A person calmed down after having a panic attack
|Classification and external resources|
|Patient UK||Panic disorder|
Panic disorder is an anxiety disorder characterized by recurring panic attacks, causing a series of intense episodes of extreme anxiety during panic attacks. It may also include significant behavioral changes lasting at least a month and of ongoing worry about the implications or concern about having other attacks. The latter are called anticipatory attacks (DSM-IVR).
Panic disorder is not the same as agoraphobia (fear of public places), although many afflicted with panic disorder also suffer from agoraphobia. Panic attacks cannot be predicted, therefore an individual may become stressed, anxious or worried wondering when the next panic attack will occur. Panic disorder may be differentiated as a medical condition, or chemical imbalance. The DSM-IV-TR describes panic disorder and anxiety differently. Whereas anxiety is preceded by chronic stressors which build to reactions of moderate intensity that can last for days, weeks or months, panic attacks are acute events triggered by a sudden, out-of-the-blue cause: duration is short and symptoms are more intense. Panic attacks can occur in children, as well as adults. Panic in young people may be particularly distressing because children tend to have less insight about what is happening, and parents are also likely to experience distress when attacks occur.
Panic disorder is a potentially disabling disorder, but can be controlled and successfully treated. Because of the intense symptoms that accompany panic disorder, it may be mistaken for a life-threatening physical illness such as a heart attack. This misconception often aggravates or triggers future attacks (some are called "anticipatory attacks"). People frequently go to hospital emergency rooms on experiencing a panic attack, and extensive medical tests may be performed to rule out other conditions, thus creating further anxiety. There are three types of panic attacks: unexpected, situationally bounded, and situationally predisposed.
Signs and symptoms
Panic disorder sufferers usually have a series of intense episodes of extreme anxiety during panic attacks. These attacks typically last about ten minutes, and can be as short-lived as 1–5 minutes, but can last twenty minutes to more than an hour, or until helpful intervention is made. Panic attacks can wax and wane for a period of hours (panic attacks rolling into one another), and the intensity and specific symptoms of panic may vary over the duration.
In some cases the attack may continue at unabated high intensity, or seem to be increasing in severity. Common symptoms of an attack include rapid heartbeat, perspiration, dizziness, dyspnea, trembling, uncontrollable fear such as: the fear of losing control and going crazy, the fear of dying and hyperventilation. Other symptoms are sweating, a sensation of choking, paralysis, chest pain, nausea, numbness or tingling, chills or hot flashes, faintness, crying and some sense of altered reality. In addition, the person usually has thoughts of impending doom. Individuals suffering from an episode have often a strong wish of escaping from the situation that provoked the attack. The anxiety of Panic Disorder is particularly severe and noticeably episodic compared to that from Generalized Anxiety Disorder. Panic attacks may be provoked by exposure to certain stimuli (e.g., seeing a mouse) or settings (e.g., the dentist's office). Other attacks may appear unprovoked. Some individuals deal with these events on a regular basis, sometimes daily or weekly. The outward symptoms of a panic attack often cause negative social experiences (e.g., embarrassment, social stigma, social isolation, etc.).
Limited symptom attacks are similar to panic attacks, but have fewer symptoms. Most people with PD experience both panic attacks and limited symptom attacks.
There is no single cause for panic disorder, however, panic disorder has been found to run in families, and suggests that inheritance plays a strong role in determining who will get it. It has also been found to exist as a co-morbid condition with many hereditary disorders, such as bipolar disorder, and a genetic predisposition to alcoholism.
Psychological factors, stressful life events, life transitions, and environment as well as often thinking in a way that exaggerates relatively normal bodily reactions are also believed to play a role in the onset of panic disorder. Often the first attacks are triggered by physical illnesses, major stress, or certain medications. People who tend to take on excessive responsibilities may develop a tendency to suffer panic attacks. Post-traumatic stress disorder (PTSD) patients also show a much higher rate of panic disorder than the general population.
There is some evidence to suggest hypoglycemia, hyperthyroidism, mitral valve prolapse, labyrinthitis, pheochromocytoma and respiratory conditions can cause or aggravate panic disorder.
Many SSRIs also have stimulant side-effects during the beginning of treatment which may exacerbate the condition and have actually caused first-time panic attacks in otherwise healthy individuals being treated for depression.
Substance abuse is often correlated with panic attacks. The majority of individuals participating in a study determined (63%) of those abusing alcohol reported that alcohol use began prior to onset of panic, and the majority (59%) of those abusing illicit drugs reported that drug use began first. The study that was conducted documented the panic-substance abuse relationship. Substance abuse began prior to onset of panic and substances were used to self-medicate for panic attacks by only a few subjects.
In another study, 100 methamphetamine dependent individuals were analyzed for co-morbid psychiatric disorders; of the 100 individuals, 36% were categorized as having co-morbid psychiatric disorders. Mood and Psychotic disorders were more prevalent than anxiety disorders, which accounted for 7% of the 100 sampled individuals.
Tobacco smoking increases the risk of developing panic disorder with or without agoraphobia and panic attacks; smoking started in adolescense or early adulthood particularly increases this risk of developing panic disorder. While the mechanism of how smoking increases panic attacks is not fully understood, a few hypotheses have been derived. Smoking cigarettes may lead to panic attacks by causing changes in respiratory function (e.g. feeling short of breath). These respiratory changes in turn can lead to the formation of panic attacks, as respiratory symptoms are a prominent feature of panic. Respiratory abnormalities have been found in children with high levels of anxiety, which suggests that a person with these difficulties may be susceptible to panic attacks, and thus more likely to subsequently develop panic disorder. Nicotine, a stimulant, could contribute to panic attacks. However, nicotine withdrawal may also cause significant anxiety which could contribute to panic attacks.
It is also possible that panic disorder patients smoke cigarettes as a form of self-medication to lessen anxiety. Nicotine and other psychoactive compounds with antidepressant properties in tobacco smoke which act as monoamine oxidase inhibitors in the brain can alter mood and have a calming effect, depending on dose.
A number of clinical studies have shown a positive association between caffeine ingestion and panic disorder and/or anxiogenic effects. People who have panic disorder are more sensitive to the anxiety provoking effects of caffeine. One of the major anxiety provoking effects of caffeine being an increase in heart rate.
Alcohol and sedatives
About 30% of people with panic disorder use alcohol and 17% use other psychoactive drugs. This is in comparison with 61% (alcohol) and 7.9% (other psychoactive drugs) of the general population who use alcohol and psychoactive drugs, respectively. Utilization of recreational drugs or alcohol generally make symptoms worse. Most stimulant drugs (caffeine, nicotine, cocaine) would be expected to worsen the condition, since they directly increase the symptoms of panic, such as heart rate.
Deacon and Valentiner (2000) conducted a study that examined co-morbid panic attacks and substance use in a non-clinical sample of young adults who experienced regular panic attacks. The authors found that compared to healthy controls, therapeutic alcohol and sedative use was greater for non-clinical participants who experienced panic attacks. These findings are consistent with the suggestion made by Cox, Norton, Dorward, and Fergusson (1989) that panic disorder patients self-medicate if they believe that certain substances will be successful in alleviating their symptoms. If panic disorder patients are indeed self-medicating, there may be a portion of the population with undiagnosed panic disorder who will not seek professional help as a result of their own self-medication. In fact, for some patients panic disorder is only diagnosed after they seek treatment for their self-medication habit.
While alcohol initially helps ease panic disorder symptoms, medium- or long-term alcohol abuse can cause panic disorder to develop or worsen during alcohol intoxication, especially during alcohol withdrawal syndrome. This effect is not unique to alcohol but can also occur with long term use of drugs which have a similar mechanism of action to alcohol such as the benzodiazepines which are sometimes prescribed as tranquilizers to people with alcohol problems. The reason chronic alcohol misuse worsens panic disorder is due to distortion of the brain chemistry and function.
Approximately 10% of patients will experience notable protracted withdrawal symptoms, which can include panic disorder, after discontinuation of benzodiazepines. Protracted withdrawal symptoms tend to resemble those seen during the first couple of months of withdrawal but usually are of a subacute level of severity compared to the symptoms seen during the first 2 or 3 months of withdrawal. It is not known definitively whether such symptoms persisting long after withdrawal are related to true pharmacological withdrawal or whether they are due to structural neuronal damage as result of chronic use of benzodiazepines or withdrawal. Nevertheless such symptoms do typically lessen as the months and years go by eventually disappearing altogether.
A significant proportion of patients attending mental health services for conditions including anxiety disorders such as panic disorder or social phobia have developed these conditions as a result of alcohol or sedative abuse. Anxiety may pre-exist alcohol or sedative independence, which then acts to perpetuate or worsen the underlying anxiety disorder. Someone suffering the toxic effects of alcohol abuse or chronic sedative use or abuse will not benefit from other therapies or medications for underlying psychiatric conditions. as they do not address the root cause of the symptoms. Recovery from sedative Symptoms may temporarily worsen during alcohol withdrawal or benzodiazepine withdrawal.
There are other researchers looking at some individuals with panic disorder as having a chemical imbalance within the limbic system and one of its regulatory chemicals GABA-A. The reduced production of GABA-A sends false information to the amygdala which regulates the body's "fight or flight response" mechanism and in return, produces the physiological symptoms that lead to the disorder. Clonazepam, an anticonvulsant benzodiazepine with a long half-life, has been successful in keeping the condition in check.
Recently, researchers have begun to identify mediators and moderators of aspects of panic disorder. One such mediator is the partial pressure of carbon dioxide, which mediates the relationship between panic disorder patients receiving breathing training and anxiety sensitivity; thus, breathing training affects the partial pressure of carbon dioxide in a patient’s arterial blood, which in turn lowers anxiety sensitivity. Another mediator is hypochondriacal concerns, which mediate the relationship between anxiety sensitivity and panic symptomatology; thus, anxiety sensitivity affects hypochondriacal concerns which, in turn, affect panic symptomatology.
Perceived threat control has been identified as a moderator within panic disorder, moderating the relationship between anxiety sensitivity and agoraphobia; thus, the level of perceived threat control dictates the degree to which anxiety sensitivity results in agoraphobia. Another recently identified moderator of panic disorder is genetic variations in the gene coding for galanin; these genetic variations moderate the relationship between females suffering from panic disorder and the level of severity of panic disorder symptomatology.
The DSM-IV-TR diagnostic criteria for panic disorder require unexpected, recurrent panic attacks, followed in at least one instance by at least a month of a significant and related behavior change, a persistent concern of more attacks, or a worry about the attack's consequences. There are two types, one with and one without agoraphobia. Diagnosis is excluded by attacks due to a drug or medical condition, or by panic attacks that are better accounted for by other mental disorders.
Panic disorder is a serious health problem that in many cases can be successfully treated, although there is no known cure. Identification of treatments that engender as full a response as possible, and can minimize relapse, is imperative. Cognitive behavioural therapy and Positive Self Talk specific for panic are the treatment of choice for panic disorder. Several studies show that 85 to 90 percent of panic disorder patients treated with CBT recover completely from their panic attacks within 12 weeks. When cognitive behavioral therapy is not an option pharmacotherapy can be used. SSRIs are considered a first line pharmacotherapeutic option.
As with many disorders, having a support structure of family and friends who understand the condition can help increase the rate of recovery. During an attack, it is not uncommon for the sufferer to develop irrational, immediate fear, which can often be dispelled by a supporter who is familiar with the condition. For more serious or active treatment, there are support groups for anxiety sufferers which can help people understand and deal with the disorder.
Current treatment guidelines American Psychiatric Association and the American Medical Association primarily recommend either cognitive-behavioral therapy or one of a variety of psychopharmacological interventions. Some evidence exists supporting the superiority of combined treatment approaches.
Another option is self-help based on principles of cognitive-behavioral therapy. Using a book or a website, a person does the kinds of exercises that would be used in therapy, but they do it on their own, perhaps with some email or phone support from a therapist. A systematic analysis of trials testing this kind of self-help found that websites, books, and other materials based on cognitive-behavioral therapy could help some people. The best-studied conditions are panic disorder and social phobia.
Panic Disorder is not the same as phobic symptoms, although phobias commonly result from panic disorder. CBT and one tested form of psychodynamic psychotherapy have been shown efficacious in treating panic disorder with and without agoraphobia. A number of randomized clinical trials have shown that CBT achieves reported panic-free status in 70-90% of patients about 2 years after treatment.
Clinically, a combination of psychotherapy and medication can often produce good results, although research evidence of this approach has been less robust. Some improvement may be noticed in a fairly short period of time — about 6 to 8 weeks. Psychotherapy can improve the effectiveness of medication, reduce the likelihood of relapse for someone who has discontinued medication, and offer help for people with panic disorder who do not respond at all to medication.
The goal of cognitive behavior therapy is to help a patient reorganize thinking processes and anxious thoughts regarding an experience that provokes panic. An approach that proved successful for 87% of patients in a controlled trial is interoceptive therapy, which simulates the symptoms of panic to allow patients to experience them in a controlled environment.
Symptom inductions generally occur for one minute and may include:
- Intentional hyperventilation – creates lightheadedness, derealization, blurred vision, dizziness
- Spinning in a chair – creates dizziness, disorientation
- Straw breathing – creates dyspnea, airway constriction
- Breath holding – creates sensation of being out of breath
- Running in place – creates increased heart rate, respiration, perspiration
- Body tensing – creates feelings of being tense and vigilant
The key to the induction is that the exercises should mimic the most frightening symptoms of a panic attack, although none of the symptoms listed above are the essence of panic attack—which is pure terrifying panic. Symptom inductions should be repeated three to five times per day until the patient has little to no anxiety in relation to the symptoms that were induced. Often it will take a period of weeks for the afflicted to feel no anxiety in relation to the induced symptoms. With repeated trials, a person learns through experience that these internal sensations do not need to be feared and becomes less sensitized or desensitized to the internal sensation. After repeated trials, when nothing catastrophic happens, the brain learns (hippocampus & amygdala) to not fear the sensations, and the sympathetic nervous system activation fades. However, in real-life situations panic may escalate independently of whether the subject is fearful of the minor symptoms associated with panic. The subject may have no fear of fast heart rate, hyperventilation or derealization, but may nevertheless feel terror, and it is the terror that may cause the other symptoms. Psychiatrists are asking subjects to feel terror but look upon it dispassionately, a situation which would require extraordinary mind control training and not contribute to the subject's quality of life. Meanwhile, there is true danger of blackouts in hyperventilation, heart attacks in racing heart rates, being out of personal control during derealization, and so on.
For patients whose panic disorder involves agoraphobia, the traditional cognitive therapy approach has been in vivo exposure, in which the affected individual, accompanied by a therapist, is gradually exposed to the actual situation that provokes panic.
Another form of psychotherapy which has shown effectiveness in controlled clinical trials is panic-focused psychodynamic psychotherapy, which focuses on the role of dependency, separation anxiety, and anger in causing panic disorder. The underlying theory posits that due to biochemical vulnerability, traumatic early experiences, or both, people with panic disorder have a fearful dependence on others for their sense of security, which leads to separation anxiety and defensive anger. Therapy involves first exploring the stressors that lead to panic episodes, then probing the psychodynamics of the conflicts underlying panic disorder and the defense mechanisms that contribute to the attacks, with attention to transference and separation anxiety issues implicated in the therapist-patient relationship.
Comparative clinical studies suggest that muscle relaxation techniques and breathing exercises are not efficacious in reducing panic attacks. In fact, breathing exercises may actually increase the risk of relapse.
Appropriate treatment by an experienced professional can prevent panic attacks or at least substantially reduce their severity and frequency — bringing significant relief to percent of people with panic disorder. Relapses may occur, but they can often be effectively treated just like the initial episode.
vanApeldoorn, F.J. et al. (2011) demonstrated the additive value of a combined treatment incorporating an SSRI treatment intervention with cognitive behavior therapy (CBT). Gloster et al. (2011) went on to examine the role of the therapist in CBT. They randomized patients into two groups: one being treated with CBT in a therapist guided environment, and the second receiving CBT through instruction only, with no therapist guided sessions. The findings indicated that the first group had a somewhat better response rate, but that both groups demonstrated a significant improvement in reduction of panic symptomatology. These findings lend credibility to the application of CBT programs to patients who are unable to access therapeutic services due to financial, or geographic inaccessibility. Koszycky et al. (2011) discuss the efficacy of self-administered cognitive behavioural therapy (SCBT) in situations where patients are unable to retain the services of a therapist. Their study demonstrates that it is possible for SCBT in combination with an SSRI to be as effective as therapist-guided CBT with SSRI. Each of these studies contribute to a new avenue of research that allows effective treatment interventions to be made more easily accessible to the population.
Appropriate medications are effective for panic disorder. Selective serotonin reuptake inhibitors are first line treatments rather than benzodiazapines due to concerns with the latter regarding tolerance, dependence and abuse. Although there is little evidence that pharmacological interventions can directly alter phobias, few studies have been performed, and medication treatment of panic makes phobia treatment far easier. Medications can include:
- Antidepressants (SSRIs, MAOIs, tricyclic antidepressants and norepinephrine reuptake inhibitors): these are taken regularly every day, and alter neurotransmitter configurations which in turn can help to block symptoms. Although these medications are described as "antidepressants", nearly all of them — especially the tricyclic antidepressants — have anti-anxiety properties, in part, due to their sedative effects. SSRIs have been known to exacerbate symptoms in panic disorder patients, especially in the beginning of treatment and have even provoked panic attacks in otherwise healthy individuals. SSRIs are also known to produce withdrawal symptoms which include rebound anxiety and panic attacks. Comorbid depression has been cited as imparting the worst course, leading to chronic, disabling illness.
- Anti-anxiety drugs (benzodiazepines): Use of benzodiazepines for panic disorder is controversial with opinion differing in the medical literature. The American Psychiatric Association states that benzodiazepines can be effective for the treatment of panic disorder and recommends that the choice of whether to use benzodiazepines, antidepressants with antipanic properties or psychotherapy should be based on the individual patient's history and characteristics. They reported that in their view there is insufficient evidence to recommend one treatment over another for panic disorder. The APA noted that while benzodiazepines have the advantage of a rapid onset of action, that this is offset by the risk of developing a benzodiazepine dependence. The National Institute of Clinical Excellence came to a different conclusion, they pointed out the problems of using uncontrolled clinical trials to assess the effectiveness of pharmacotherapy and based on placebo controlled research they concluded that benzodiazepines were not effective in the long-term for panic disorder and recommended that benzodiazepines not be used for longer than 4 weeks for panic disorder. Instead NICE clinical guidelines recommend alternative pharmacotherapeutic or psychotherapeutic interventions. Other experts believe that benzodiazepines are best avoided due to the risks of the development of tolerance and physical dependence. The World Federation of Societies of Biological Psychiatry, say that benzodiazepines should not be used as a first line treatment option but are an option for treatment resistant cases of panic disorder. Despite increasing focus on the use of antidepressants and other agents for the treatment of anxiety as recommended best practice, benzodiazepines have remained a commonly used medication for panic disorder.
It typically begins during early adulthood; roughly half of all people who have panic disorder develop the condition before age 24, especially those subjected to traumatic experiences. However, some sources say that the majority of young people affected for the first time are between the ages of 25 and 30. Women are twice as likely as men to develop panic disorder.
Panic disorder can continue for months or years, depending on how and when treatment is sought. If left untreated, it may worsen to the point where one's life is seriously affected by panic attacks and by attempts to avoid or conceal the condition. In fact, many people have had problems with personal relationships or employment while struggling to cope with panic disorder. Some people with panic disorder may conceal their condition because of the stigma of mental illness. In some individuals, symptoms may occur frequently for a period of months or years, then many years may pass without symptoms. In some cases, the symptoms persist at the same level indefinitely. There is also some evidence that many individuals (especially those who develop symptoms at an early age) may experience symptom cessation later in life (e.g. past age 50).
In 2000, the World Health Organization found prevalence and incidence rates for panic disorder to be very similar across the globe. Age-standardized prevalence per 100,000 ranged from 309 in Africa to 330 in East Asia for men and from 613 in Africa to 649 in North America, Oceania, and Europe for women.
A retrospective study has shown that 40% of adult panic disorder patients reported that their disorder began before the age of 20. In an article examining the phenomenon of panic disorder in youth, Diler et al. (2004) found that only a few past studies have examined the occurrence of juvenile panic disorder. They report that these studies have found that the symptoms of juvenile panic disorder almost replicate those found in adults (e.g. heart palpitations, sweating, trembling, hot flashes, nausea, abdominal distress, and chills). The anxiety disorders co-exist with staggeringly high numbers of other mental disorders in adults. The same comorbid disorders that are seen in adults are also reported in children with juvenile panic disorder. Last and Strauss (1989) examined a sample of 17 adolescents with panic disorder and found high rates of comorbid anxiety disorders, major depressive disorder, and conduct disorders. Eassau et al. (1999) also found a high number of comorbid disorders in a community-based sample of adolescents with panic attacks or juvenile panic disorder. Within the sample, adolescents were found to have the following comorbid disorders: major depressive disorder (80%), dysthymic disorder (40%), generalized anxiety disorder (40%), somatoform disorders (40%), substance abuse (40%), and specific phobia (20%). Consistent with this previous work, Diler et al. (2004) found similar results in their study in which 42 youths with juvenile panic disorder were examined. Compared to non-panic anxiety disordered youths, children with panic disorder had higher rates of comorbid major depressive disorder and bipolar disorder.
Children differ from adolescents and adults in their interpretation and ability to express their experience. Like adults, children experience physical symptoms including accelerated heart rate, sweating, trembling or shaking, shortness of breath, nausea or stomach pain, dizziness or light-headedness. In addition children also experience cognitive symptoms like fear of dying, feelings of being detached from oneself, feelings of losing control or going crazy, but they are unable to vocalize these higher order manifestations of fear. They simply know that something is going wrong and that they are very afraid. Children can only describe the physical symptoms. They have not yet developed the constructs to put these symptoms together and label them as fear. Parents often feel helpless when they watch a child suffer. They can help children give a name to their experience, and empower them to overcome the fear they are experiencing
The role of the parent in treatment and intervention for children diagnosed with panic disorder is discussed by McKay & Starch (2011). They point out that there are several levels at which parental involvement should be considered. The first involves the initial assessment. Parents as well as the child should be screened for attitudes and treatment goals, as well as for levels of anxiety or conflict in the home. The second involves the treatment process in which the therapist should meet with the family as a unit as frequently as possible. Ideally all family members should be aware and trained in the process of cognitive behaviour therapy (CBT) in order to encourage the child to rationalize and face fears rather than employ avoidant safety behaviours. McKay & Storch (2011) suggest training/modeling of therapeutic techniques and in session involvement of the parents in the treatment of children to enhance treatment efficacy.
Despite the evidence pointing to the existence of early-onset panic disorder, the DSM-IV-TR currently only recognizes six anxiety disorders in children: separation anxiety disorder, generalized anxiety disorder, specific phobia, obsessive-compulsive disorder, social anxiety disorder (a.k.a. social phobia), and post-traumatic stress disorder. Panic disorder is notably excluded from this list.
- Phil Barker (7 October 2003). Psychiatric and mental health nursing: the craft of caring. Arnold. pp. 215–. ISBN 978-0-340-81026-2. Retrieved 4 December 2010.
- "Anxiety Attacks Versus Panic Attacks - Difference Between Panic and Anxiety Attacks". Panicdisorder.about.com. Retrieved 28 June 2013.
- Herr, NR; Williams JW, Jr; Benjamin, S; McDuffie, J (Jul 2, 2014). "Does this patient have generalized anxiety or panic disorder?: The Rational Clinical Examination systematic review.". JAMA : the journal of the American Medical Association 312 (1): 78–84. PMID 25058220.
- American psychiatric association 2000
- depression and anxiety 27:93-112, 2010.
- marquez (N.D). Panic Disorder Respiratory Subtype: Psychopathology, Laboratory Challenge Tests, and Response to Treatment.
- Diler et al., (2004) Cognitive-Behavioral Treatment of Adolescent Panic.
- Frisch, N. and Frisch, L. 2006. Psychiatric Mental Health Nursing. 3rd ed. Canada: Thomson Delmar Learning.
- Healy (2009) Psychiatric Drugs Explained
- "Panic Disorder and Pharmacological Treatment Options". Retrieved 12 May 2012.
- Ludewig S, Geyer MA, Ramseier M, Vollenweider FX, Rechsteiner E, Cattapan-Ludewig K (January 2005). "Information-processing deficits and cognitive dysfunction in panic disorder". J Psychiatry Neurosci 30 (1): 37–43. PMC 543839. PMID 15644996.
- Department of Family Practice, University of Texas Health Science Center, San Antonio (1999). "Relationship between substance abuse and panic attacks". pubmed.gov. Retrieved 26 March 2014.
- "Psychiatric disorders in individuals with methamphetamine dependence: prevalence and risk factors". pubmed.gov. Retrieved 8 March 2014.
- Roy-Byrne PP, Craske MG, Stein MB (September 2006). "Panic disorder". The Lancet 368 (9540): 1023–32. doi:10.1016/S0140-6736(06)69418-X. PMID 16980119.
- Cosci F, Knuts IJ, Abrams K, Griez EJ, Schruers KR (May 2010). "Cigarette smoking and panic: a critical review of the literature". Journal of Clinical Psychiatry 71 (5): 606–15. doi:10.4088/JCP.08r04523blu. PMID 19961810.
- Johnson JG, Cohen P, Pine DS, Klein DF, Kasen S, Brook JS (November 2000). "Association between cigarette smoking and anxiety disorders during adolescence and early adulthood". JAMA 284 (18): 2348–51. doi:10.1001/jama.284.18.2348. PMID 11066185.
- Isensee B, Wittchen HU, Stein MB, Höfler M, Lieb R (July 2003). "Smoking increases the risk of panic: findings from a prospective community study". Arch. Gen. Psychiatry 60 (7): 692–700. doi:10.1001/archpsyc.60.7.692. PMID 12860773.
- Goodwin RD, Lewinsohn PM, Seeley JR (1 November 2005). "Cigarette smoking and panic attacks among young adults in the community: the role of parental smoking and anxiety disorders". Biological Psychiatry 58 (9): 686–93. doi:10.1016/j.biopsych.2005.04.042. PMID 16018987.
- Breslau N, Klein DF (December 1999). "Smoking and panic attacks: an epidemiologic investigation". Archives of General Psychiatry 56 (12): 1141–7. doi:10.1001/archpsyc.56.12.1141. PMID 10591292.
- Pine DS, Klein RG, Coplan JD, et al. (October 2000). "Differential carbon dioxide sensitivity in childhood anxiety disorders and nonill comparison group". Archives of General Psychiatry 57 (10): 960–7. doi:10.1001/archpsyc.57.10.960. PMID 11015814.
- Gorman JM, Kent J, Martinez J, Browne S, Coplan J, Papp LA (February 2001). "Physiological changes during carbon dioxide inhalation in patients with panic disorder, major depression, and premenstrual dysphoric disorder: evidence for a central fear mechanism". Archives of General Psychiatry 58 (2): 125–31. doi:10.1001/archpsyc.58.2.125. PMID 11177114.
- Hughes RN (June 1996). "Drugs which Induce Anxiety: Caffeine". New Zealand Journal of Psychology 25 (1): 36–42. doi:10.1016/S0278-6915(02)00096-0. PMID 12204388.
- Vilarim, Marina Machado; Rocha Araujo, Daniele Marano; Nardi, Antonio Egidio (August 2011). "Caffeine challenge test and panic disorder: A systematic literature review". Expert Review of Neurotherapeutics 11 (8): 1185–95. doi:10.1586/ern.11.83. PMID 21797659.
- Halter (2008). Foundations of Psychiatric Mental Health Nursing: A Clinical Approach.
- Lara DR (2010). "Caffeine, mental health, and psychiatric disorders". J. Alzheimers Dis. 20 (Suppl 1): S239–48. doi:10.3233/JAD-2010-1378. PMID 20164571.
- Lee MA, Flegel P, Greden JF, Cameron OG (May 1988). "Anxiogenic effects of caffeine on panic and depressed patients". American Journal of Psychiatry 145 (5): 632–35. PMID 3358468. Retrieved 28 June 2013.
- Nardi AE, Lopes FL, Valença AM, Freire RC, Veras AB, de-Melo-Neto VL, Nascimento I, King AL, Mezzasalma MA, Soares-Filho GL, Zin WA (May–June 2007). "Caffeine challenge test in panic disorder and depression with panic attacks". Comprehensive Psychiatry 48 (3): 257–63. doi:10.1016/j.comppsych.2006.12.001. PMID 17445520. Retrieved 28 June 2013.
- "Panic Disorder". Mental Health America. Retrieved 2 July 2007.
- "FASTSTATS — Alcohol Use". Centers for Disease Control and Prevention. Retrieved 28 June 2013.
- "FASTSTATS — Illegal Drug Use". Centers for Disease Control and Prevention. 2013-05-30. Retrieved 28 June 2013.
- "Practice guideline for the treatment of patients with panic disorder. Work Group on Panic Disorder.". American Journal of Psychiatry 155 (5 Suppl): 1–34. May 1998. PMID 9585731.
- Deacon BJ, Valentiner DP (2000). "Substance use and non-clinical panic attacks in a young adult sample". Journal of Substance Abuse 11 (1): 7–15. doi:10.1016/S0899-3289(99)00017-6. PMID 10756510.
- Cox BJ, Norton GR, Dorward J, Fergusson PA (1989). "The relationship between panic attacks and chemical dependencies". Addictive Behaviour 14 (1): 53–60. doi:10.1016/0306-4603(89)90016-6. PMID 2718824.
- Cox BJ, Norton GR, Swinson RP, Endler NS (1990). "Substance abuse and panic-related anxiety: a critical review". Behaviour Research and Therapy 28 (5): 385–93. doi:10.1016/0005-7967(90)90157-E. PMID 2256896.
- Terra MB, Figueira I, Barros HM (August 2004). "Impact of alcohol intoxication and withdrawal syndrome on social phobia and panic disorder in alcoholic inpatients". Revista do Hospital das Clínicas 59 (4): 187–92. doi:10.1590/S0041-87812004000400006. PMID 15361983.
- Wetterling T and Junghanns K (December 2000). "Psychopathology of alcoholics during withdrawal and early abstinence". European Psychiatry 15 (8): 483–8. doi:10.1016/S0924-9338(00)00519-8. PMID 11175926.
- Cowley DS (24 January 1992). "Alcohol abuse, substance abuse, and panic disorder". American Journal of Medicine 92 (1A): 41S–8S. doi:10.1016/0002-9343(92)90136-Y. PMID 1346485.
- Cosci F, Schruers KR, Abrams K, Griez EJ (June 2007). "Alcohol use disorders and panic disorder: a review of the evidence of a direct relationship". Journal of Clinical Psychiatry 68 (6): 874–80. doi:10.4088/JCP.v68n0608. PMID 17592911.
- Ashton H (1991). "Protracted withdrawal syndromes from benzodiazepines". Journal of Substance Abuse and Treatment 8 (1–2): 19–28. doi:10.1016/0740-5472(91)90023-4. PMID 1675688.
- Cohen SI (February 1995). "Alcohol and benzodiazepines generate anxiety, panic and phobias". Journal of the Royal Society of Medicine 88 (2): 73–7. PMC 1295099. PMID 7769598.
- Belleville G, Morin CM (March 2008). "Hypnotic discontinuation in chronic insomnia: impact of psychological distress, readiness to change, and self-efficacy". Health Psychology 27 (2): 239–48. doi:10.1037/0278-6188.8.131.52. PMID 18377143.
- Professor C Heather Ashton (1987). "Benzodiazepine Withdrawal: Outcome in 50 Patients". British Journal of Addiction 82: 655–671.
- Onyett SR (April 1989). "The benzodiazepine withdrawal syndrome and its management". Journal of the Royal College of General Practitioners 39 (321): 160–3. PMC 1711840. PMID 2576073.
- Spindustry Systems, www.spindustry.com (2007-08-06). "Psychiatry Weekly: Symptoms of Panic Disorder Linked to Benzodiazepine Binding Activity in the Insular Cortex". Psychweekly.com. Retrieved 28 June 2013.
- Meuret AE, Rosenfield D, Hofmann SG, Suvak MK, Roth WT (March 2009). "Changes in respiration mediate changes in fear of bodily sensations in panic disorder". J Psychiatr Res 43 (6): 634–41. doi:10.1016/j.jpsychires.2008.08.003. PMC 3327292. PMID 18835608.
- Berrocal C, Moreno FR, Cano J (2007). "Anxiety sensitivity and panic symptomology: the mediator role of hypochondriacal concerns". Span J Psychol 10 (1): 159–66. doi:10.1017/s1138741600006429. PMID 17549889.
- White KS, Brown TA, Somers TJ, Barlow DH (January 2006). "Avoidance behavior in panic disorder: the moderating influence of perceived control". Behav Res Ther 44 (1): 147–57. doi:10.1016/j.brat.2005.07.009. PMID 16300725.
- Unschuld PG, Ising M, Erhardt A, et al. (January 2008). "Polymorphisms in the galanin gene are associated with symptom-severity in female patients suffering from panic disorder". J Affect Disord 105 (1–3): 177–84. doi:10.1016/j.jad.2007.05.006. PMID 17573119.
- American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders. 4th, text revision (DSM-IV-TR) ed. 2000. ISBN 0-89042-025-4. Panic Disorder without Agoraphobia. Panic Disorder with Agoraphobia.
- Salvador-Carulla L, Seguí J, Fernández-Cano P, Canet J (April 1995). "Costs and offset effect in panic disorders". Br J Psychiatry Suppl (27): 23–8. PMID 7794590.
- Ellis, Ross; Ryan, J. A. (2005). "Emotional Intelligence and Positive Psychology: Therapist Tools for Training/Coaching Clients to Move Beyond Emotional Relief". Annals of the American Psychotherapy Assn 8 (3): 42-43.
- Nolen-Hoeksema, Susan. Abnormal Psychology. McGraw-Hill. p. 132. ISBN 0078035384.
- Cloos, Jean-Marc (2005). "The Treatment of Panic Disorder". Curr Opin Psychiatry 18 (1): 45–50. PMID 16639183. Retrieved 25 September 2007.
- Foldes-Busque, G.; Marchand, A.; Landry, P. (Oct 2007). "L'identification et traitement du trouble panique avec ou sans agoraphobie: Mise à jour". Can Fam Physician 53 (10): 1686–93. PMC 2231433. PMID 17934032.
- Rathgeb-Fuetsch, M., Kempter, G., Feil, A., Pollmächer, T., Schuld, A. (2011). Short- and long-term efficacy of cognitive behavioural therapy for DSM-IV panic disorder in patients with and without severe psychiatric comorbidity. Journal of Psychiatric Research, 45, 1264-1268. doi:10.1016/j.jpsychires.1.03.018
- Seguí, J.; Márquez, M.; Canet, J.; García, L. (1999). "[Causes of failure in psychopharmacological treatment of anxiety disorder]". Actas Esp Psiquiatr 27 (4): 250–8. PMID 10469946.
- Barlow DH, Gorman JM, Shear MK, Woods SW (May 2000). "Cognitive-behavioral therapy, imipramine, or their combination for panic disorder: A randomized controlled trial". JAMA 283 (19): 2529–36. doi:10.1001/jama.283.19.2529. PMID 10815116.
- Marks IM, Swinson RP, Başoğlu M, et al. (June 1993). "Alprazolam and exposure alone and combined in panic disorder with agoraphobia. A controlled study in London and Toronto". Br J Psychiatry 162 (6): 776–87. doi:10.1192/bjp.162.6.776. PMID 8101126.
- Wiborg IM, Dahl AA (August 1996). "Does brief dynamic psychotherapy reduce the relapse rate of panic disorder?". Arch. Gen. Psychiatry 53 (8): 689–94. doi:10.1001/archpsyc.1996.01830080041008. PMID 8694682.
- Lewis, C; Pearce, J; Bisson, JI (January 2012). "Efficacy, cost-effectiveness and acceptability of self-help interventions for anxiety disorders: systematic review". The British journal of psychiatry : the journal of mental science 200 (1): 15–21. doi:10.1192/bjp.bp.110.084756. PMID 22215865.
- PubMed Health. "Featured review". PubMed Health. NCBI.
- American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders. 4th, text revision (DSM-IV-TR) ed. 2000. ISBN 0-89042-025-4.
- Milrod BL, Leon AC, Barber JP, Markowitz JC, Graf E (June 2007). "Do comorbid personality disorders moderate panic-focused psychotherapy? An exploratory examination of the American Psychiatric Association practice guideline". J Clin Psychiatry 68 (6): 885–91. doi:10.4088/JCP.v68n0610. PMID 17592913.
- Barlow DH, Gorman JM, Shear MK, Woods SW (May 2000). "Cognitive-behavioral therapy, imipramine, or their combination for panic disorder: A randomized controlled trial". JAMA 283 (19): 2529–36. doi:10.1001/jama.283.19.2529. PMID 10815116.
- Choy Y (February 1, 2008). "Treatment Planning for Panic Disorder". Psychiatric Times 25 (2).
- Busch FN and Milrod BL (February 1, 2008). "Panic-Focused Psychodynamic Psychotherapy". Psychiatric Times 25 (2).
- Schmidt NB, Woolaway-Bickel K, Trakowski J et al. (2000). "Dismantling cognitive-behavioral treatment for panic disorder: questioning the utility of breathing retraining". J Consult Clin Psychol 68 (3): 417–424. doi:10.1037/0022-006X.68.3.417. PMID 10883558.
- "Panic Disorder". National Institute of Mental Health. Archived from the original on 2006-04-28. Retrieved 12 May 2006.
- van Apeldoorn F.J., van Hout W.J.P.J., Mersch P.P.A., Huisman M., Slaap B.R., Hale W.W.III, den Boer J.A. (2008). "Is a combined therapy more effective than either CBT or SSRI alone? Results of a multicenter trial on panic disorder with or without agoraphobia". Acta Psychiatrica Scandinavica 117 (4): 260–270. doi:10.1111/j.1600-0447.2008.01157.x. PMID 18307586.
- Gloster A.T., Wittchen H-U, Lang T., Helbig-Lang S., Fydrich T., Fehm L., Volker A. (2011). "Psychological treatment for panic disorder with agoraphobia: A randomized controlled trial to examine the role of therapist-guided exposure in situ in CBT". Journal of Consulting and Clinical Psychology 79 (3): 406–420. doi:10.1037/a0023584. PMID 21534651.
- Koszycki D., Taljaard M., Segal Z., Bradwejn J. (2011). "A randomized trial of sertraline, self-administered cognitive behavior therapy, and their combination for panic disorder". Psychological Medicine 41 (2): 373–383. doi:10.1017/S0033291710000930.
- Moylan S, Giorlando F, Nordfjærn T, Berk M (March 2012). "The role of alprazolam for the treatment of panic disorder in Australia". Aust N Z J Psychiatry 46 (3): 212–24. doi:10.1177/0004867411432074. PMID 22391278.
- Roy-Byrne PP, Stang P, Wittchen HU, Ustun B, Walters EE, Kessler RC (March 2000). "Lifetime panic-depression comorbidity in the National Comorbidity Survey. Association with symptoms, impairment, course and help-seeking". Br J Psychiatry 176 (3): 229–35. doi:10.1192/bjp.176.3.229. PMID 10755069.
- Hollifield M, Katon W, Skipper B, et al. (June 1997). "Panic disorder and quality of life: variables predictive of functional impairment". Am J Psychiatry 154 (6): 766–72. PMID 9167503.
- Work Group on Panic Disorder (January 2009). "APA Practice Guideline for the Treatment of Patients With Panic Disorder, Second Edition" (PDF). Retrieved 12 July 2009.
- McIntosh A, Cohen A, Turnbull N et al. (2004). "Clinical guidelines and evidence review for panic disorder and generalised anxiety disorder" (PDF). National Collaborating Centre for Primary Care. Retrieved 16 June 2009.
- Damsa C, Lazignac C, Iancu R, et al. (February 2008). "[Panic disorders: differential diagnosis and care in emergencies]". Rev Med Suisse (in French) 4 (144): 404–6, 408–9. PMID 18320769.
- Bandelow, B.; Zohar, J.; Hollander, E.; Kasper, S.; Möller, HJ.; World Federation of Societies of Biological Psychiatry Task Force on Treatment Guidelines for Anxiety, Obsessive-Compulsive and Posttraumatic Stress Disorders (Oct 2002). "World Federation of Societies of Biological Psychiatry (WFSBP) guidelines for the pharmacological treatment of anxiety, obsessive-compulsive and posttraumatic stress disorders". World J Biol Psychiatry 3 (4): 171–99. doi:10.3109/15622970209150621. PMID 12516310.
- Bruce SE, Vasile RG, Goisman RM, et al. (2003). "Are benzodiazepines still the medication of choice for patients with panic disorder with or without agoraphobia?". Am J Psychiatry 160 (8): 1432–8. doi:10.1176/appi.ajp.160.8.1432. PMID 12900305.
- Stevens JC, Pollack MH (2005). "Benzodiazepines in clinical practice: consideration of their long-term use and alternative agents". J Clin Psychiatry. 66. Suppl 2: 21–7. PMID 15762816.
- "Caffeine abstention in the management of anxiety disorders". Retrieved 26 March 2014.
- Prasad, Chandan (2005). Nutritional Neuroscience. CRC Press. p. 351. ISBN 0415315999. Retrieved 7 October 2012.
- Nehlig, Astrid (2004). Coffee, Tea, Chocolate, and the Brain. CRC Press. p. 136. ISBN 0415306914. Retrieved 7 October 2012.
- Juliano LM, Griffiths RR (2004). "A critical review of caffeine withdrawal: empirical validation of symptoms and signs, incidence, severity, and associated features". Psychopharmacology (Berl.) 176 (1): 1–29. doi:10.1007/s00213-004-2000-x. PMID 15448977.
- "Facts about Panic Disorder". National Institute of Mental Health. Archived from the original on 2006-09-07. Retrieved 30 September 2006.
- Ayuso-Mateos, Jose Luis. "Global burden of panic disorder in the year 2000". World Health Organization. Retrieved 27 February 2013.
- Moreau DL, Follet C (1993). "Panic disorder in children and adolescents". Child Adolesc Psychiatr Clin N Am 2: 581–602.
- Diler RS, Birmaher B, Brent DA et al. (2004). "Phenomenology of panic disorder in youth". Depress Anxiety 20 (1): 39–43. doi:10.1002/da.20018. PMID 15368595.
- Alessi NE, Magen J; Magen (November 1988). "Panic disorder in psychiatrically hospitalized children". Am J Psychiatry 145 (11): 1450–2. PMID 3189608.
- Biederman J, Faraone SV, Marrs A et al. (February 1997). "Panic disorder and agoraphobia in consecutively referred children and adolescents". J Am Acad Child Adolesc Psychiatry 36 (2): 214–23. doi:10.1097/00004583-199702000-00012. PMID 9031574.
- Essau CA, Conradt J, Petermann F; Conradt; Petermann (1999). "Frequency of panic attacks and panic disorder in adolescents". Depress Anxiety 9 (1): 19–26. doi:10.1002/(SICI)1520-6394(1999)9:1<19::AID-DA3>3.0.CO;2-# (inactive 2015-01-09). PMID 9989346.
- King NJ, Gullone E, Tonge BJ, Ollendick TH; Gullone; Tonge; Ollendick (January 1993). "Self-reports of panic attacks and manifest anxiety in adolescents". Behav Res Ther 31 (1): 111–6. doi:10.1016/0005-7967(93)90049-Z. PMID 8417721.
- Macauly JL, Kleinknecht RA; Kleinknecht (1989). "Panic and panic attacks in adolescents". J Anxiety Disord 3 (4): 221–41. doi:10.1016/0887-6185(89)90016-9.
- de Reiter C, Rifkin H, Garssen B, Van Schawk A; Rijken; Garssen; Van Schaik; Kraaimaat (1989). "Comorbidity among the anxiety disorders". J Anxiety Disord 3 (2): 57–68. doi:10.1016/0887-6185(89)90001-7.
- Last CG, Strauss CC; Strauss (1989). "Panic disorder in children and adolescents". J Anxiety Disord 3 (2): 87–95. doi:10.1016/0887-6185(89)90003-0.
- Beidel D.C., & Alfano, C.A. (2011) Child Anxiety Disorders: A Guide to Research and Treatment. (2nd Ed.) Routledge Taylor & Frances Group, New York, U.S.A.
- Lewin, A.B. (2011) Parent Training for Childhood Anxiety. In McKay, D, & Storch, E.A. (Eds.), Handbook of Child & Adolescent Anxiety Disorders. (pp.405-417). New York: Springer Science + Business Media doi:10.1007/978-1-4419-7784-7