Many things can cause temporary psychosis. Environmental triggers, such as losing a loved one, are known to contribute, as may excessive stress, or the interaction of strong social demands with a pre-existing vulnerability of self.
Other causes that have been identified include lack of sleep, fever, brain damage, and even hypnosis.
War/battlefield experience may also trigger a psychotic break: when reality becomes unbearable, the mind temporarily breaks with it.
Parenthood may occasionally set off a psychotic break in men, as may giving birth in women who have previously denied their pregnancy.
The compulsive drug user may find their ego dissociating in a psychotic break if habituation means the drug can no longer fulfil its defensive function.
Symptoms of psychotic breaks vary greatly, usually depending on the circumstances of diagnosis or any contributary substance ingested. Symptoms can range from harmless, sometimes unnoticed delusions, to violent outbursts and major depression. The sufferer may also be unable to distinguish reality from fantasy (for example, believing that a dream really happened or experiencing hallucinations that appear to be real.) Where a bipolar disorder is involved, crying, grandiosity, insomnia, irritability, and persecutory delusions may all or severally manifest themselves as symptoms.