Psychosis refers to an abnormal condition of the mind, and is a generic psychiatric term for a mental state often described as involving a “loss of contact with reality”. People suffering from psychosis are described as psychotic.
There are 12 recognised forms:
Schizophrenia: A psychiatric disorder characterised by disordered thinking and behaviour, which often includes delusions and hallucinations. Psychotic symptoms are experienced for at least six months, together with significant social or occupational dysfunction.
Schizophreniform disorder: Symptoms are similar to schizophrenia, but persist for between one and six months.
Schizoaffective disorder: Prominent mood symptoms occur with the characteristic symptoms of schizophrenia, but occasionally psychotic symptoms are experienced in the absence of mood symptoms.
Delusional disorder: Involves holding strong, false beliefs (delusions). Hallucinations are usually not present. Apart from the impact of the delusions, psychosocial functioning may not be markedly impaired nor behaviour blatantly strange. However, under some circumstances delusions are sufficiently false to cause problems with day-to-day life.
Substance-induced psychosis: Drug and alcohol use or withdrawal can result in psychotic symptoms. These may disappear once the effects of the substances or withdrawal symptoms wear off. In some cases, psychosis persists after the initial substance-induced psychosis. This is common with stimulant drugs, e.g. methamphetamine.
Dementia: Psychotic symptoms may appear with memory disturbances in conditions that cause physiological deterioration of the brain, such as a head injury, AIDS, post-encephalitis, Alzheimer’s Disease or a brain tumour.
Bipolar Disorder (Manic Depression): Psychosis generally appears as part of a more general severe mood disturbance. Psychotic symptoms tend to match your mood. (For example, when depressed, you may hear voices urging you to commit suicide.)
Major Depressive Disorder: Psychosis can be a feature of a severe major depression.
Postpartum psychosis: Psychosis that may develop during the six month period after childbirth. This is usually part of a severe mood disorder.
Delirium: Psychotic symptoms may be part of an acute confusional state that results from another severe medical disorder, such as meningitis, septicaemia or after an epileptic convulsion.
Brief psychotic episode: Psychotic symptoms appear suddenly in response to a recognisable and highly stressful life event, such as being a victim of violent crime. Symptoms may be severe but are short-lived: the psychosis lasts between one day and one month. You may or may not be aware of your bizarre behaviour.
Psychosis due to a general medical condition: Psychotic symptoms may appear as a result of brain tumours, epilepsy, and other chronic medical conditions. The psychotic symptoms can sometimes be the first sign of the underlying medical condition.