dyslimbic
10-02-2006, 06:25 PM
Cannabis use increases mania risk
2 October 2006
Cannabis use appears to increase the risk of mania, say researchers who believe their findings could indicate that users of the drug have an increased risk of developing bipolar disorder and psychosis.
They suggest that the association between cannabis use and mania may be linked to the "sensation" of dopamine, whereby repeated, intermittent stimulant exposure produces a permanent change in dopaminergic responses.
Cécile Henquet, from Maastricht University in The Netherlands, and colleagues interviewed 4815 individuals aged between 18 and 64 years about their use of cannabis at baseline and again 1 and 3 years later. Assessments of manic and psychotic symptoms were also included.
People using cannabis at baseline were 5.32 times more likely to experience manic episodes during follow-up than people who did not use cannabis.
Taking into account age, gender, educational level, ethnicity, single marital status, neuroticism, use of other drugs, alcohol use, and depressive and manic symptoms at baseline attenuated the association, but it remained significant, at an odds ratio of 2.70.
The association between cannabis use and mania was independent of the prevalence and incidence of psychotic symptoms. There was also no evidence of reverse causality, with manic symptoms at baseline not predicting the onset of cannabis use during follow-up, which rules out the "self-medication" hypothesis as a contributing factor.
The researchers note that their data were suggestive of a dose-response relationship between frequency of exposure and mania outcome.
Reporting in the Journal of Affective Disorders, Henquet et al comment: "Recent findings suggest that subthreshold expressions of mania show continuity with clinical bipolar disorder.
"The association between cannabis and manic symptoms as described in the current study may thus not only apply to the lower ends of the continuum, but may play a role in the expression of clinical bipolar disorder as well."
Source: J Affect Disord 2006; 95: 103–110
2 October 2006
Cannabis use appears to increase the risk of mania, say researchers who believe their findings could indicate that users of the drug have an increased risk of developing bipolar disorder and psychosis.
They suggest that the association between cannabis use and mania may be linked to the "sensation" of dopamine, whereby repeated, intermittent stimulant exposure produces a permanent change in dopaminergic responses.
Cécile Henquet, from Maastricht University in The Netherlands, and colleagues interviewed 4815 individuals aged between 18 and 64 years about their use of cannabis at baseline and again 1 and 3 years later. Assessments of manic and psychotic symptoms were also included.
People using cannabis at baseline were 5.32 times more likely to experience manic episodes during follow-up than people who did not use cannabis.
Taking into account age, gender, educational level, ethnicity, single marital status, neuroticism, use of other drugs, alcohol use, and depressive and manic symptoms at baseline attenuated the association, but it remained significant, at an odds ratio of 2.70.
The association between cannabis use and mania was independent of the prevalence and incidence of psychotic symptoms. There was also no evidence of reverse causality, with manic symptoms at baseline not predicting the onset of cannabis use during follow-up, which rules out the "self-medication" hypothesis as a contributing factor.
The researchers note that their data were suggestive of a dose-response relationship between frequency of exposure and mania outcome.
Reporting in the Journal of Affective Disorders, Henquet et al comment: "Recent findings suggest that subthreshold expressions of mania show continuity with clinical bipolar disorder.
"The association between cannabis and manic symptoms as described in the current study may thus not only apply to the lower ends of the continuum, but may play a role in the expression of clinical bipolar disorder as well."
Source: J Affect Disord 2006; 95: 103–110