Dimethyltryptamine (DMT) was detected in the urine of 47% of patients diagnosed with schizophrenia, 38% of those with other non-affective psychoses, 13% of those with affective psychoses, 19% of those with neurotic and personality disorders, and 5% of normal subjects. Operational definitions of psychosis did not identify any group more strongly associated with urinary DMT than a hospital diagnosis of schizophrenia. A discriminant function analysis of symptoms identified a group of 21 patients, of whom 71% excreted detectable DMT. A general relationship between psychotic symptoms and urinary DMT existed, but specifically schizophrenic symptoms were not major determinants of DMT excretion.
Childhood adversity and cannabis use are both known risk factors for psychosis. This study examined whether cannabis use might explain the link between childhood adversity and psychotic disorders. Data from 881 first-episode psychosis patients and 1231 controls from the EU-GEI study showed that household discord was associated with psychosis partly through cannabis use. Lifetime cannabis use mediated 17% of the association, cannabis potency mediated 14%, and frequency of use mediated 29%. Similar results appeared for early exposure to household discord. The findings suggest that harmful cannabis use patterns partially explain how household discord leads to psychosis, and children exposed to challenging home environments could benefit from interventions to prevent cannabis misuse.