bradafoster asked:
In the book and movie “Fight Club”, the main character develops a split personality seemingly because of his insomnia. Is this a realistic effect of insomnia? Have there been any documented cases? Please supply documentation, if possible.
no..because there is no such documented real proof of multiple personalities..
Insomnia does not cause split personality disorder, but can be a symptom of the disease, it may also be a symptom of bipolar disorder. but these disorders are not caused by insomnia, insomnia can be caused by them. Insomnia though in long term cases can cause personality changes due to lack of REM sleep which is needed for the brain to get rid of excess energy, when it has no release it starts to deteriorate fast.