BERLIN– Alcohol dependence and major depressive disorder are similarly potent yet independent risk factors for suicidal behavior, according to Dr. Philip Gorwood.

Although alcohol use disorder and major depression are extremely common and often comorbid, the mechanisms by which they boost the risk for suicidal behavior are very different, he said at the annual congress of the European College of Neuropsychopharmacology.

“The ideation about suicidal behavior comes from the mood disorder, but the organization of the behavior – the suicidal attempt, especially when it is unplanned and impulsive – is driven by the alcohol consumption,” said Dr. Gorwood, professor of psychiatry at Rene Descartes University, Paris.

“The real take-home message is the difference between suicidal ideas and impulsive acts. Probably that was not well understood before. Alcohol dependence has no relationship with suicidal ideas. But once you have those ideas, alcohol consumption becomes very important in the risk of suicidal behavior,” he said.

A recent retrospective analysis of nearly 451,000 French patients hospitalized for suicide attempts during 2004-2011 showed their most common psychiatric diagnosis was major depressive disorder, present in 52% of the men and 65% of the women. Second most common – and far ahead of the rest of the pack – was alcohol use disorder, diagnosed in 36% of the hospitalized men and 49% of the women.

Alcohol probably facilitates suicidal behaviors in a variety of ways – by generating stressful life events, weakening social supports, worsening mood, restricting cognition and thereby inhibiting coping strategies, boosting impulsivity, and promoting inaccurate assessment of harm and pain.

A recent review of epidemiologic studies on the risk factors for suicide attempts and suicide among individuals with alcohol use disorder identified a clutch of risk factors that could be useful in clinical practice as a means of targeting problem drinkers at increased risk for suicidality: major depressive disorder, greater severity of alcohol use disorder, limited social support, stressful life events, aggression, medical illness, and economic adversity (Am. J. Prev. Med. 2014;47:S204-S208).

Other studies have identified additional risk factors that distinguish individuals with alcohol dependence who do attempt suicide from those who don’t: early onset of alcohol dependence, childhood trauma, a family history of suicidal behavior, and tobacco dependence. But if a clinician is going to rely on the two strongest risk factors in order to identify increased suicidal risk among alcohol-dependent patients, those would be major depression and the greater severity of alcohol dependence, according to Dr. Gorwood.

A study from the National Comorbidity Survey Replication based on a representative sample comprised of 9,282 U.S. adults concluded that alcohol abuse or dependence was associated with a 2.1-fold increased risk of a history of a suicide attempt, while major depressive disorder was independently associated with a 2.0-fold increased risk. In a multivariate analysis, major depressive disorder was associated with a statistically significant 2.3-fold increased risk of suicidal ideation but no significant increase in planned or unplanned suicide attempts. In contrast, alcohol abuse or dependence wasn’t associated with a significant increase in suicidal ideation but did carry a 2.9-fold increased risk of unplanned, impulsive suicide attempts (Mol. Psychiatry 2010;15:868-76).

A first-of-its-kind U.S. national study of postmortem blood alcohol levels as a means of assessing alcohol use prior to suicide concluded that men and women who committed suicide were 1.8- and 2.4-fold more likely, respectively, to have consumed alcohol within 48 hours prior to their death, compared with matched living controls. More importantly, in a multivariate analysis adjusted for potential confounders, men and women who committed suicide were 6.2-fold and 10-fold more likely to have been intoxicated. The investigators concluded that it’s essential for suicide prevention programs to include components that discourage intoxication (Ann. Epidemiol. 2014;24:588-92).

Dr. Gorwood said a popular misconception among clinicians is that focusing solely on antidepressant therapy in patients with major depressive disorder and comorbid alcohol dependence will reduce their risk of suicidal behavior. A large Finnish national study scrutinizing the use of antidepressants and cause-specific mortality over the course of a decade showed this is not the case (J. Affect. Disord. 2013;148:278-85).

“The Finnish data means that probably if you are not also taking care of the alcohol dependence, then independently treating the associated mood disorder will not be an efficient way of reducing the suicide risk,” Dr. Gorwood noted.

He added, however, that getting patients with alcohol use disorder to stop drinking is hardly a panacea.

“We shouldn’t be naive. Stopping drinking alcohol will not resolve a lot of the difficulties that affect these patients. They have to build a new life and new types of functioning, and it’s difficult. There’s a lot of work to do. But it’s a very important step in reducing suicidal risk.”

Dr. Gorwood reported receiving research grants from Eli Lilly and Servier, and serving on scientific advisory boards or speakers panels for those pharmaceutical companies and eight others.

bjancin@frontlinemedcom.com

New insights into relationship between alcohol, depression, and suicide