A clinical comparison of schizophrenia with and without pre-onset cannabis use disorder: a retrospective cohort study using categorical and dimensional approaches

Annals of General Psychiatry, Dec 2015

Background A high prevalence of cannabis use disorder has been reported in subjects suffering from schizophrenia, fuelling intense debate about whether schizophrenia with pre-onset cannabis use disorder may be a distinct entity with specific features or whether cannabis use disorder can precipitate schizophrenia in genetically vulnerable subjects. Methods We retrospectively assessed schizophrenia subjects with and without pre-onset cannabis use disorder on the basis of their clinical features, assessed categorically and dimensionally with the operational criteria checklist for psychotic illnesses (OCCPI). We also investigated whether the two groups could be differentiated on the basis of a history of psychiatric disorders in first-degree relatives. A principal component factor analysis of the OCCPI items was used to identify specific symptom dimensions. The relationships between symptom dimensions and cannabis status were analysed by point-biserial correlation analysis to control for sex and age at time of the assessment and illness duration. Results One hundred and seventy-one subjects with a diagnosis of schizophrenia were included. Among them, forty-one patients (18.2 % of the sample) had a cannabis use disorder before or at the time of the onset of schizophrenia. We found similar results in symptoms patterns or family history between patients with and without pre-onset cannabis use disorder. Conclusions Our results clearly argue against cannabis-associated schizophrenia being a relevant distinct clinical entity of schizophrenia with specific features.

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A clinical comparison of schizophrenia with and without pre-onset cannabis use disorder: a retrospective cohort study using categorical and dimensional approaches

Sarrazin et al. Ann Gen Psychiatry A clinical comparison of schizophrenia with and without pre-onset cannabis use disorder: a retrospective cohort study using categorical and dimensional approaches Samuel Sarrazin 0 2 3 Florence Louppe 0 3 Raphael Doukhan 0 3 Franck Schürhoff 0 1 2 3 4 0 AP-HP, DHU PePSY, Hôpitaux universitaires Henri-Mondor, Pôle de Psychiatrie et d'Addictologie , 94000 Créteil , France 1 Faculté de Médecine, Université Paris-Est , 94000 Créteil , France 2 INSERM U955 , Equipe 15, IMRB, 94000 Créteil , France 3 AP-HP, DHU PePSY, Hôpitaux universitaires Henri-Mondor, Pôle de Psychiatrie et d'Addictologie , 94000 Créteil , France 4 FondaMental Fondation, Fondation de coopération scientifique , 94000 Créteil , France Background: A high prevalence of cannabis use disorder has been reported in subjects suffering from schizophrenia, fuelling intense debate about whether schizophrenia with pre-onset cannabis use disorder may be a distinct entity with specific features or whether cannabis use disorder can precipitate schizophrenia in genetically vulnerable subjects. Methods: We retrospectively assessed schizophrenia subjects with and without pre-onset cannabis use disorder on the basis of their clinical features, assessed categorically and dimensionally with the operational criteria checklist for psychotic illnesses (OCCPI). We also investigated whether the two groups could be differentiated on the basis of a history of psychiatric disorders in first-degree relatives. A principal component factor analysis of the OCCPI items was used to identify specific symptom dimensions. The relationships between symptom dimensions and cannabis status were analysed by point-biserial correlation analysis to control for sex and age at time of the assessment and illness duration. Results: One hundred and seventy-one subjects with a diagnosis of schizophrenia were included. Among them, forty-one patients (18.2 % of the sample) had a cannabis use disorder before or at the time of the onset of schizophrenia. We found similar results in symptoms patterns or family history between patients with and without pre-onset cannabis use disorder. Conclusions: Our results clearly argue against cannabis-associated schizophrenia being a relevant distinct clinical entity of schizophrenia with specific features. Schizophrenia; Psychosis; Cannabis; Symptom dimension; OCCPI Background A high prevalence of cannabis use has repeatedly been reported in psychotic patients [ 1 ]. Previous systematic reviews have reported a wide range (13–45 %) in the rates of cannabis use disorders (CUD) in schizophrenia users [ 2, 3 ], with a median lifetime rate estimated at 27.1  % [4]. Apart from the fact that acute intoxication can lead to ‘psychotic-like’ experiences that do not persist beyond the period of intoxication [ 5 ], various possibilities have been discussed for the association between cannabis and schizophrenia which include: (a) cannabis use is a component cause of schizophrenia; (b) the hypothesis of “self-medication” for symptoms of psychiatric diseases such as the negative symptoms of schizophrenia, anxiety, depression or dysphoria and (c) common socio-demographic factors and shared genetic factors. Several studies have shown that the use of cannabis leads to physiological and cognitive deficits of a similar nature to those seen in schizophrenia [ 6 ]. In particular, there is an increasing body of evidence demonstrating that cannabis users (without schizophrenia) show deficits in tasks of sustained attention, working memory and other executive functions [ 7 ], as well as abnormalities in automatic processing of auditory stimuli: P50 suppression [ 8 ], prepulse inhibition (PPI) [ 9 ] and the mismatch negativity (MMN) [ 10 ] of the event-related potential (ERP). This suggests that dysfunctions in the endocannabinoid system could be involved in the development of similar deficits associated with cannabis use and schizophrenia, and further proposes that the neurobiology underpinning the development of electrophysiological/ cognitive deficits in cannabis users may overlap with the neurobiological underpinnings of schizophrenia. Other data suggest that the link between cannabis use and schizophrenia might be causal, even if a direct cause–effect relationship between the two disorders has not been clearly established. Systematic reviews regarding the association between cannabis and psychosis have suggested that cannabis can increase the lifetime risk of psychosis by a factor of two or three [ 11–13 ] and metaanalytic approaches found that the risk of psychosis was approximately 40 % higher in cannabis users than in nonusers [ 14 ]. In the causal hypothesis, cannabis use may be directly involved in the pathophysiological processes that lead to a distinct form of schizophrenia-spectrum disorder that would have never happened otherwise. This is different from the hypothesis in which cannabis use may act (...truncated)


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Samuel Sarrazin, Florence Louppe, Raphael Doukhan, Franck Schürhoff. A clinical comparison of schizophrenia with and without pre-onset cannabis use disorder: a retrospective cohort study using categorical and dimensional approaches, Annals of General Psychiatry, 2015, pp. 44, 14, DOI: 10.1186/s12991-015-0083-x