Suicide methods and presence of intoxicating abusable substances: some clinical and public health implications

Selective alterations of the CB1 receptors and the fatty acid amide hydrolase in the ventral striatum of alcoholics and suicides

Recent studies in rodents have suggested a role for the central endocannabinoid system in the regulation of mood and alcohol related behaviors. Alcohol use disorder is often associated with suicidal behavior. In the present study, we examined whether abnormalities in the endocannabinoid system in the ventral striatum are associated with alcohol dependence and suicide. The levels of CB1 receptors, receptor-mediated G-protein signaling, and activity and level of the fatty acid amide hydrolase (FAAH) were analyzed postmortem in the ventral striatum of alcohol-dependent nonsuicides (CA, n=9), alcohol-dependent suicides (AS, n=9) and nonpsychiatric controls (C, n=9). All subjects underwent a psychological autopsy, and toxicological and neuropathological examinations. The levels of the CB1 receptors and the CB1 receptor-mediated G-protein signaling were significantly lower in the ventral striatum of CA compared to the control group. However, these parameters were elevated in AS when compared to CA group. The activity of FAAH enzyme was lower in CA compared to the control group while it was found to be significantly higher in AS compared with CA group. These findings suggest that alcohol dependence is associated with the downregulation of the CB1 receptors, while suicide is linked to the upregulation of these receptors in the ventral striatum. Alteration in the activity of FAAH enzyme that regulates the anandamide (AEA) content might in turn explain differences in the CB1 receptor function in alcohol dependence and suicide. These findings may have etiological and therapeutic implications for the treatment of alcohol addiction and suicidal behavior.

Predictors of high rates of suicidal ideation among drug users

Several studies have attempted to understand the link among substance abuse, depression, and suicidal ideation (SI). Assessment of this link is important to develop specific interventions for persons in substance abuse treatment. This association was tested among 990 drug users in and out of treatment with significant criminal justice histories from two National Institute on Drug Abuse studies. The Diagnostic Interview Schedule and Substance Abuse Module assessed DSM-III-R depression, number of depression criteria met, antisocial personality disorder (ASPD), and substance use disorders. Compared with men, women were twice as likely to report depression (24% vs. 12%), whereas men were nearly twice as likely to report ASPD (42% vs. 24%). High rates of SI were found, with women more likely than men to report thoughts of death (50% vs. 31%), wanting to die (39% vs. 21%), thoughts of committing suicide (47% vs. 33%), or attempting suicide (33% vs. 11%); 63% of women and 47% of men reported at least one of these suicidal thoughts or behaviors. Male and female ideators were more likely than nonideators to report depressed mood and to meet criteria for depression, ASPD, and alcohol use disorders. Male ideators were more likely than male nonideators to meet criteria for cocaine use disorders. Using logistic regression, SI among men was predicted by alcohol use disorder (OR = 1.60), ASPD (OR = 1.59), and number of depression criteria (OR = 9.38 for five criteria). Among women, SI was predicted by older age, marital status, alcohol use disorder (OR = 2.77), and number of depression criteria (OR = 9.12 for five criteria). These original findings point out the need to discuss suicidal thoughts among depressed drug users for early treatment and prevention.