What Causes It?

There are many theories about the causes of Psychosis, but no definite answers.

There are 3 main theories



There is strong evidence that some psychoses involve a dysfunction in neurotransmitters in the brain. Neurotransmitters are the “chemical messengers” of the brain. They transmit impulses throughout the brain and the Central Nervous System. Of particular importance is the neurotransmitter Dopamine. Most anti-psychotic drugs that control the positive symptoms of Psychosis also block the transmission of Dopamine.


Individuals whose close relatives experience Psychosis are themselves at increased risk. For example, the risk of developing Psychosis associated with Schizophrenia in the general population is approximately 1%, yet the children and siblings of those with Schizophrenia have respective lifetime risks of 13% and 9%.

Brain Changes

Changes have been found in the brains of some individuals with Schizophrenia, which appear to have been present since birth or early childhood. Possible causes of the changes include: genetic transmission, abnormal neurodevelopment and pregnancy or birth complications (e.g. exposure of mother to a virus during the second Trimester of pregnancy).