Cannabis and schizophrenia: a longitudinal study of cases treated in Stockholm County

Abstract

By means of the Stockholm County inpatient care register we identified all cases treated with a diagnosis of cannabis dependence and psychosis, not necessarily at the same occasion, during 1971-1983. By scrutinizing medical records, we evaluated the diagnosis according to DSM-III-R and we assessed the history of substance abuse as well as the psychiatric history and clinical course. We identified 229 cases during the follow-up; 112 of these cases (49%) fulfilled the DSM-III-R criteria for schizophrenia. The majority of the schizophrenics had prominent positive symptoms and a sudden onset of disease, and 69% of the cases had a record of heavy cannabis abuse at least 1 year before onset of psychotic symptoms. The high number of verified DSM-III-R cases of schizophrenia in this cohort and the temporal relation between cannabis abuse and schizophrenia further support the hypothesis that cannabis abuse may be a risk factor for schizophrenia. We confirmed previous observations that cannabis-associated schizophrenia often has a sudden onset and prominent positive symptoms.

Does substance use disorder affect clinical expression in first-hospitalization patients with schizophrenia? Analysis of a prospective cohort

“…The substance most commonly used is cannabis, followed by cocaine, amphetamine, hallucinogen and other drugs (Allebeck et al, 1993;Hambrecht and Häfner, 2000;Compton et al, 2009Compton et al, , 2011. Moreover high frequency of polysubstance abuse and misuse are reported Barnett et al, 2007).…”

Relationship between Cannabis Use, Schizotypal Traits, and Cognitive Function in Healthy Subjects

“…Cannabis use is a predictor of the later development of schizophrenia [1,2]; probably cannabis use precipitates schizophrenia in individuals with a latent liability [3]. Furthermore, schizophrenic patients run the risk of psychotic relapse or exacerbation by use of even moderate amounts of cannabis [4,5].…”

Development of CIE-10 and DSM-IV cannabis disorders / Desarrollo de la CIE-10 y el DSM-IV para trastornos por cánnabis

“…Los síntomas positivos que muestran los esquizofrénicos con antecedentes de cannabismo incluyen trastornos de conducta y alucinaciones, en especial de tipo auditivo con voces que comentan los pensamientos del enfermo (Negrete, 1988;Allebeck et al, 1993).…”