Maladaptive Daydreaming or excessive daydreaming is a psychological concept first introduced by Eli Somer to describe a proposed condition in which a person excessively daydreams or fantasizes, sometimes as a response to prior psychological trauma or abuse. This mental disorder is not psychotic or schizophrenic as those affected by this are aware of the difference between reality and fantasy, sometimes painfully. This disorder only becomes truly harmful when it interferes with a person's daily life to the point where it impedes their ability to eat, sleep, etc. 
- Fantasy prone personality
- Repressed memory
- Attention-Deficit Hyperactivity Disorder
- Obsessive-Compulsive Disorder
- Major Depressive Disorder
- Borderline Personality Disorder
- Bipolar Disorder
- Somer, Eli. "Maladaptive Daydreaming: A Qualitative Inquiry". Journal of Contemporary Psychotherapy. Journal of Contemporary Psychotherapy. Retrieved 18 May 2014.
- Ardino, Vittoria (ed.). Post-Traumatic Syndromes in Childhood and Adolescence. Chichester, West Sussex, UK: Wiley-Blackwell. p. 162. ISBN 978-0-470-66929-7.