Behavioural despair test
The behavioural despair test (or Porsolt forced swimming test) is a test, centered on a rodent's response to the threat of drowning, whose result has been interpreted as measuring susceptibility to negative mood. It is commonly used to measure the effectiveness of antidepressants, although significant criticisms of its interpretation have been made.
Animals are subjected to two trials during which they are forced to swim in an acrylic glass cylinder filled with water, and from which they cannot escape. The first trial lasts 15 minutes. Then, after 24-hours, a second trial is performed that lasts 5 minutes. The time that the test animal spends in the second trial without making any movements beyond those required to keep its head above water is measured. This immobility time is decreased by various types of antidepressants and also by electroconvulsive shock. Another common variant of this behavioral test specifically used for mice is conducted only for one trial and lasts six minutes. Modern implementations of the test score swimming and climbing behaviours separately, because swimming behaviour has been shown to be increased by selective serotonin reuptake inhibitors, while climbing behaviour is increased by selective norepinephrine reuptake inhibitors such as desipramine and maprotiline.
Controversy in interpretation
Classically, immobility in the second test has been interpreted as a behavioral correlate of negative mood, representing a kind of hopelessness in the animal. Rodents given antidepressants swim harder and longer than controls (which forms the basis for claims of the test's validity). However, there is some debate between scientists whether increased immobility instead demonstrates learning or habituation, and would therefore be a positive behavioral adaptation: the animal is less fearful because it is now familiar with the environment of the test. This interpretation is supported by the fact that even rats who are first put into a container from which they can escape (and therefore do not experience despair) show reduced mobility in the second test.
The term "behavioral despair test" bears an anthropomorphic connotation and is a somewhat subjective description as it is uncertain whether the test reliably gauges mood or despair. Strictly speaking, the descriptive term "forced swimming test" should be preferred.
- Petit-Demouliere, B; Chenu, F; Bourin, M (January 2005). "Forced swimming test in mice: a review of antidepressant activity.". Psychopharmacology 177 (3): 245–55. doi:10.1007/s00213-004-2048-7. PMID 15609067.
- Borsini, Franco, Giovanna Volterra, and Alberto Meli. "Does the behavioral "despair" test measure "despair"?." Physiology & behavior 38.3 (1986): 385-386.
- Porsolt, RD; Le Pichon, M; Jalfre, M (21 April 1977). "Depression: a new animal model sensitive to antidepressant treatments.". Nature 266 (5604): 730–2. doi:10.1038/266730a0. PMID 559941.
- Porsolt, RD; Bertin, A; Jalfre, M (October 1977). "Behavioral despair in mice: a primary screening test for antidepressants.". Archives internationales de pharmacodynamie et de therapie 229 (2): 327–36. PMID 596982.
- Can, A.; et, al. (2012). "The Mouse Forced Swim Test". Journal of Visualized Experiments 59 (3638): e3638. doi:10.3791/3638. PMID 22314943.
- Detke, MJ; Rickels, M; Lucki, I (September 1995). "Active behaviors in the rat forced swimming test differentially produced by serotonergic and noradrenergic antidepressants.". Psychopharmacology 121 (1): 66–72. doi:10.1007/bf02245592. PMID 8539342.
- "Porsolt Forced Swim Test — Penn State University". Research.psu.edu. 2013-04-29. Retrieved 2014-03-24.
- Borsini, F; Meli, A (1988). "Is the forced swimming test a suitable model for revealing antidepressant activity?". Psychopharmacology 94 (2): 147–60. doi:10.1007/bf00176837. PMID 3127840.
- O'Neill, KA; Valentino, D (12 March 1982). "Escapability and generalization: effect on 'behavioral despair'.". European Journal of Pharmacology 78 (3): 379–80. doi:10.1016/0014-2999(82)90043-7. PMID 7067732.