Brief psychotic disorder (BPD) according to DSM-5 is the sudden onset of psychotic behavior that lasts less than 1 month followed by complete remission with possible future relapses.

Source : Stephen A, Lui F. Brief Psychotic Disorder. In: StatPearls.

It presents one or more of the following symptoms :

• Delusions
• Hallucinations
• Disorganized speech
• Grossly disorganized or catatonic behavior

The causes are unknown. Some research groups suggest a genetic component, as BPD seems to be more common in families with other mood disorders. There are also (sometimes, but not always) links with some kind of severe stress and/or trauma.

In addition, the prevalence of BPD in the general population has not been accurately assessed, though it's generally considered 'uncommon'.- perhaps less than 0.01% (see article cited above).

Also see : Schizophreniaplugin-autotooltip__plain plugin-autotooltip_bigSchizophrenia

"Schizophrenia is a mental disorder characterized by abnormal social behavior and failure to understand what is real. Common symptoms include false beliefs, unclear or confused thinking, auditory and visual hallucinations, reduced social engagement and emotional expression, and a lack of motivation."