What causes Psychosis?

Scientists are yet to determine the causes of psychosis, however, it is agreed that it is brain disease, and studies indicate that the symptoms of psychosis could be due to the imbalance of dopamine, a neurotransmitter in the brain. 

Is it genetic?
A family history of psychosis is associated with a higher likelihood of developing the disorder. However it is likely to be a polygenic condition.

Is it stress-related?
Most patients experience stressful events prior to the onset of psychosis (such as: marriage, emigration, school transferring, relationship break-up, unemployment, public examinations, domestic violence, loss of loved ones), however the relationship between stress and psychosis is not necessarily unidirectional, and it is possible for stressful events to be the products of prodromal symptoms experienced by the patient as their daily lives may have been affected by the symptoms.  

Is it drug-related?
Certain drugs such as ketamine and cocaine can induce psychosis symptoms temporarily. Research shows that long-term abuse of drugs such as cannabis, could lead to a higher chance of developing psychosis in the future, even though the user has stopped using the drugs.

Is it related to one’s upbringing?
Some studies show that prenatal infection, malnutrition, obstetrics complications, childhood abuse or trauma could increase one’s chance of developing psychosis.

The above factors may affect dopamine activities in the brain, which is associated with psychosis. Scientists are still trying to understand the relationship between these factors and the brain activity and hence development of psychosis, and examining other potential factors that may increase the chance of one developing psychosis. The brain is a very complex organ and our understanding of its function and mechanisms is still rudimentary. More research will be needed to understand the brain and the mechanisms of developing psychosis.