Primary and secondary affective disorders in a sample of alcohol dependent inpatients: sociodemographic differences
© The Author(s) 2006
Published: 28 February 2006
Several studies indicate that patients with comorbid alcohol dependence and affective syndromes can be differentiated on the basis of the time of onset of mood symptoms relative to alcohol abuse. However, there are limited data on the underlying pathogenetic mechanisms and risk factors that differentiate between primary and secondary affective disorders (AD) in the context of alcohol dependence. In the present study we investigated the sociodemographic characteristics, family history and the course of illness in cases of comorbid alcohol dependence and AD.
Materials and methods
Forty-two inpatients who met the DSM-IV criteria for both alcohol dependence and a comorbid affective disorder were assessed during alcohol detoxification by the Composite International Diagnostic Interview and were also interviewed by semistructured instruments. Based on the time of onset of the AD, patients were divided in two groups: those with a primary AD and those with a secondary AD to alcohol dependence. Sociodemographic and clinical variables were statistically tested for association with either primary or secondary AD.
In our sample, 24 (57.1%) patients had major depression, 14 (33.3%) dysthymia and 4 (9.5%) a bipolar disorder. Fifteen (35.7%) patients were identified as having a primary AD and 27 (64.3%) as having a secondary AD. The only significant difference between the two groups was that of gender representation (46.7% vs 77.8% of male subjects, respectively, p = 0.040). There were no significant differences in terms of the age at onset of both the disorders between the two groups. The secondary AD group had a higher percentage of positive family history for alcoholism than that of primary AD group (53.8% vs 20.0%, p = 0.034), whereas the primary AD group had a higher percentage of positive family history for mood disorders than the secondary AD group (86.7% vs 42.3%, p = 0.005). A positive association between family history of mood disorders and primary comorbid AD was found using a multivariate logistic regression (B = 2.016, S.E. = 0.929, p = 0.030).
Our findings offer support to the notion that primary and secondary AD in alcoholics might represent different nosological entities with different genetic predisposition.