Cannabis and psychiatric syndrome

It has long been known that cannabis consumption may cause a number of psyc hopathological reactions. Mental effects of cannabis range from acute intox ication to long-standing psychiatric disorders. Research on the association between cannabis and psychiatric disorders is difficult, since there are a number of confounding factors and since many persons with psychiatric diso rders use cannabis. Thus the causal pathways linking cannabis to psychiatri c disorders are particularly difficult to elucidate. Although it is clear t hat cannabis may precipitate or aggravate psychotic reactions, it has been debated whether cannabis is an independent risk factor for schizophrenia. T he paper summarizes the major psychiatric syndromes that may be associated with cannabis consumption and also Swedish studies that give support to the hypothesis that cannabis is a risk factor for schizophrenia.