BACKGROUND : Cannabis use may trigger or perpetuate clinical features of schizophrenia in vulnerable individuals, thereby contributing to
the morbidity of schizophrenia and its burden of disease. These findings have mostly not considered the views of schizophrenia patients on
cannabis use and its effect on their mental health.
METHODS : A semi-structured 16-point opinion-type questionnaire was formulated from the results of a previous qualitative study on
schizophrenia patients’ opinions about cannabis use. The questionnaire was applied to 60 participants from an inpatient schizophrenia
population at Weskoppies Hospital, Pretoria, South Africa, who had a Diagnostic and Statistical Manual of Mental Disorders, 4th edition
(text revision) (DSM-IV-TR) diagnosis of schizophrenia and a documented history of cannabis use.
RESULTS : According to participants’ responses, 61.7% admitted to suffering from a mental illness, 95.0% admitted to using cannabis in the
past, and 20.0% of participants admitted to the current use of cannabis. Over half (51.7%) of the participants responded that cannabis had
adverse effects on their mental health, 26.7% that their mental illness was caused by using an illicit drug other than cannabis, 26.7% that only
impure cannabis had adverse effects on their mental health, and 48.3% that only using too much cannabis had bad effects on their mind. A
high percentage (58.3%) of participants responded that cannabis use helped reduce tension, 56.7% that it helped reduce anxiety, 66.7% that
it helped to lift their mood, 63.3% that it helped them to relax, 60.0% that it helped to relieve their boredom, 43.3% that it helped them feel
more energetic, 58.3% that it helped them sleep better, 13.3% that it helped reduce auditory hallucinations, and 31.7% that the beneficial
effects of cannabis outweighed its negative effects.
CONCLUSION : Most of the participants who responded that they were not using cannabis currently had positive views about its effects on their
mental health, despite responding that cannabis may have adverse effects on their mental health. This is a worrisome outcome, since those
participants who feel that cannabis has more beneficial than detrimental effects might not remain abstinent.