What is the cause of psychosis


In the middle of the 19th century, when the term first appeared, organic diseases of the nervous system, i.e. pathological changes in the brain, were suspected to be the causes of psychoses. In fact, psychotic symptoms such as hearing voices or delusions can also be caused by organic diseases of the nervous system, such as dementia. In newer classification systems for diseases (e.g. ICD-10), psychotic disorders that are not based solely on organic diseases are divided into schizophrenia, bipolar affective disorders and schizoaffective disorders. A genetic predisposition (e.g. if one of the parents already had psychotic symptoms) in combination with an acute life crisis can lead to the appearance of the first symptoms; in the case of schizophrenia, it is often drug consumption that promotes the occurrence of the disease. An imbalance in the production of a messenger substance in the brain, the neurotransmitter dopamine, is also being considered as a possible trigger for psychosis.


Symptoms of psychotic disorders affect various basic functions of the human psyche:






including acoustic, visual, physical hallucinations

Affected person hears voices, sees or feels something that is not there (e.g. certain forms or pain)


E.g. slowing down of thinking, confusion, delusion

The thought process is slower, what is said is incoherent, delusional thoughts arise (e.g. paranoia)

Ego functions

including thought spreading, thought deprivation, thought inspiration

Affected person has the feeling that thoughts do not belong to him alone or are taken away or entered by others

Focus and attention

inter alia, perception disorders, concentration disorders

Questions or stories are not understood, it is difficult for those affected to stick to the point


including listlessness

Lack of energy


i.a. depression, lack of affect, mania / hypomania

Gloomy and negative basic attitude, flattened emotional experience, pathological high mood / slightly elevated mood


The symptoms mentioned occur to varying degrees in the various forms of schizophrenia and schizoaffective disorders. In bipolar affective disorders, drive and affectivity are particularly disturbed.



The course of schizophrenia is very different: there can be continuous and phased courses

occur, whereby the psychotic symptoms are sometimes more pronounced, sometimes less pronounced or even disappear completely. In around 20%, the first psychotic phase heals completely and no further symptoms appear later. Around 60% of those affected can work despite being ill, and only around 10% require care. Around 10% of those affected eventually commit suicide.


Bipolar affective disorder

Bipolar affective disorders typically occur between the ages of 25 and 30; the course is characterized by the alternation of depressive and manic phases and phases without any symptoms. If bipolar affective disorder is not treated, there are often more than 10 episodes of illness during a lifetime, with the times without symptoms becoming shorter and shorter. Around 15% of those affected commit suicide.


Schizoaffective Disorders

In schizoaffective disorders, the course is also phased, similar to bipolar affective disorders. Chronic changes in character (e.g. persistent paranoia) do not usually occur; in the long term, the course is more favorable for those affected.