Cannabis and Schizophrenia


While experts believe that drug use and abuse does not cause schizophrenia, statistics show that schizophrenics are much more likely to have a substance abuse problem than the general population. One substance used by up to 40% of schizophrenics is cannabis, and recent research is finding evidence that cannabis use may impact age of onset, symptomatology, and hospitalization rates among schizophrenics.

It has long been known that cannabis can cause psychosis even in healthy people, and research has shown that it can also increase schizophrenia symptoms in those with the disease. Additional studies have found that cannabis use in adolescence is associated with a significantly increased risk of developing schizophrenia later in life, and may lower the age of onset of the disease by years among those predisposed to developing it.

Research studies have also found that schizophrenia patients who use cannabis have more hospitalizations for psychotic symptoms, decreased social and cognitive function, less compliance with medication regimens, and more relapses.

Many scientists believe that these study results indicate that the brain systems affected by cannabis are also involved in schizophrenia. At least one study is underway to determine whether the CB1 receptor, a protein in the brain targeted by cannabis, is different in people with and without schizophrenia. This study and studies like it may help to shed more light on the precise relationship between cannabis and schizophrenia.