Familial Predisposition for Psychiatric Disorder

[Dragonfan]

Archives of General Psychiatry

Comparison of Subjects Treated for Cannabis-Induced Psychosis and Schizophrenia

Mikkel Arendt, MScPsych, PhD; Preben B. Mortensen, DrMedSc; Raben Rosenberg, DrMedSc; Carsten B. Pedersen, MSc; Berit L. Waltoft, MSc. Arch Gen Psychiatry. 2008;65(11):1269-1274.

Context Cannabis-induced psychosis is considered a distinct clinical entity in the existing psychiatric diagnostic systems. However, the validity of the diagnosis is uncertain.

 

Objectives To establish rate ratios of developing cannabis-induced psychosis associated with predisposition to psychosis and other psychiatric disorders in a first-degree relative and to compare them with the corresponding rate ratios for developing schizophrenia spectrum disorders.

 

Design A population-based cohort was retrieved from the Danish Psychiatric Central Register and linked with the Danish Civil Registration System. History of treatment of psychiatric disorder in family members was used as an indicator of predisposition to psychiatric disorder. Rate ratios of cannabis-induced psychosis and schizophrenia associated with predisposition to psychiatric disorders were compared using competing risk analyses.

 

Setting Nationwide population-based sample of all individuals born in Denmark between January 1,1955, and July 1, 1990 (N = 2 276 309).

 

Patients During the 21.9 million person-years of follow-up between 1994 and 2005, 609 individuals received treatment of a cannabis-induced psychosis and 6476 received treatment of a schizophrenia spectrum disorder.

 

Results In general, the rate ratios of developing cannabis-induced psychosis and schizophrenia spectrum disorder associated with predisposition to schizophrenia spectrum disorder, other psychoses, and other psychiatric disorders in first-degree relatives were of similar magnitude. However, children with a mother with schizophrenia were at a 5-fold increased risk of developing schizophrenia and a 2.5-fold increased risk of developing cannabis-induced psychosis. The risk of a schizophrenia spectrum disorder following a cannabis-induced psychosis and the timing of onset were unrelated to familial predisposition.

 

Conclusions Predisposition to both psychiatric disorders in general and psychotic disorders specifically contributes equally to the risk of later treatment because of schizophrenia and cannabis-induced psychoses. Cannabis-induced psychosis could be an early sign of schizophrenia rather than a distinct clinical entity.

 

Author Affiliations: Centre for Psychiatric Research, Aarhus University Hospital, Risskov (Drs Arendt and Rosenberg), and National Centre for Register-Based Research, University of Aarhus (Dr Mortensen and Messrs Pedersen and Waltoft), Aarhus, Denmark.

[Frazz]

Very brief and very interesting i would like to read it, but is there anyway to read the paper without paying money ..

or asking the 'brain' aka danoz ?

 

[Dragonfan]

Very brief and very interesting i would like to read it, but is there anyway to read the paper without paying money ..

or asking the 'brain' aka danoz ?

 

Danoz has a brain, oh that's right, he sits on it all day