Objectives:
Both cannabinoids and psychoactive substances from the group of stimulants can have a significant effect on the induction, course and treatment of severe mental illness. They also can be treated as self-medication. Many patients feel subjective benefits of using psychoactive substances in the areas of social competence, to cope with side effects of neuroleptics, stress accompanying mental illness or to control its symptoms. Our research tries to explain the causes of taking psychoactive substances by patients with schizophrenia.

Methods:
A total of 50 schizophrenia patients using cannabinoids, including 25 of them using also stimulants, took part in our research. They filled out questionnaires about the causes of drug use and subjectively perceived mental complaints. We analyzed medical documentation.

Results:
It was found that subjects using both cannabinoids and stimulants pointed to spirituality as a cause significantly more often than subjects taking only cannabinoids. Marijuana and hashish were significantly more often taken to improve social relations. In both groups, the most common reasons were: curiosity, the need to relax, problem solving, improving relationships, and remedy for ‘shyness’. In the group using only cannabinoids, it was observed that people who felt misunderstood often smoked marijuana to solve problems. Individuals using stimulants often complained of poor concentration.

Conclusions:
Ignorance of the consequences of using psychoactive substances in people at risk of schizophrenia or in those already ill is an additional risk factor. The results may indicate an increased demand for psychoeducation and social support regarding many areas of life of patients suffering from schizophrenia.