What are the types of Psychosis? When someone has a psychosis, a diagnosis of a particular psychotic illness is usually given. A diagnosis means identification of an illness by a person’s symptoms and the diagnosis will depend on what brought on the illness and how long the symptoms last. Many psychotic symptoms like hallucinations and delusions are common to all psychoses. This means that the boundaries between the different types of psychosis are blurred and it is often difficult to make a decision. The most common conditions in which psychosis occur are: • Brief Psychotic Disorder - This is a psychosis that lasts less than one week that is a reaction to a severe stress. It can involve quite severe symptoms but recovery is quick. • Organic Psychosis - This type of psychosis can be clearly related to a physical problem that disrupts brain functioning and is caused by illness or head injury. • Substance-Induced Psychosis - This type of psychosis is associated with alcohol or drug abuse or withdrawal. It is usually brief with psychotic symptoms resolving as the effects of the substances wear off, although in some cases longer lasting psychotic illness seems to begin with substance induced psychosis. • • Bipolar Disorder (or Manic-Depression) - Bipolar Disorder is a mood disorder which may or may not be accompanied by psychotic symptoms. Prominent symptoms are extremes of mood both highs (mania) and lows (depression). Psychotic symptoms when present fit in with the person’s mood. • • Major Depressive Episode with Psychotic Features (or Psychotic Depression) - This diagnosis is made when there is depression with psychotic symptoms but without mania (high). • • Schizophrenia - This type of psychosis includes hallucinations, delusions and changes in behaviour, feelings and thinking that have been continuing for a period of at least six months. • Schizophreniform Disorder - A psychosis like Schizophrenia however the symptoms last more than one month and less than six months. • • Schizoaffective Disorder - This diagnosis is made when the person has symptoms of both a mood disorder (depression or mania) and psychosis. .