Co-Occurring Alcohol Dependence and Depression Versus Depression On Its Own: a Comparison of Service Use Among Depressed Individuals with and without a History of Alcohol Dependence in a Heterogeneous Community Sample

Background and Purpose: Although many effective treatments exist for alcohol use disorders (AUDs), few of those who might benefit from these services actually receive treatment. Individuals with AUD constitute a population that has an alarmingly low rate of treatment utilization. In the general United States population, rates of lifetime alcohol treatment for persons with AUD have been estimated at 14.6% (Cohen et al, 2007). Epidemiologic studies have found that alcohol dependent individuals with co-occurring depression have higher rates of service seeking. However, studies have yet to compare service seeking that is attributed to depression across individuals with and without alcohol dependence. To address this gap in the literature, the current study uses a case-control design to identify the extent to which lifetime depression is differentially associated with service seeking among individuals with versus without a history of stable alcohol dependence.

Method: This study included 444 participants from the 1997 Health Services Use and Cost (HSUC) study, a 14-year follow-up of individuals who were interviewed in the 1981-1983 St Louis Epidemiologic Catchment Area (ECA) study. A case-control design frequency matched individuals (on age, gender and race) who met criteria for DSM-III alcohol dependence in at least two ECA interview waves to two control groups: individuals unaffected by alcohol, and individuals with heavy drinking. The response rate was 82.9% for those alive and capable of re-interview. Interview data from three waves of HSUC (collected at six month intervals) provided information on DSM-IV psychiatric diagnoses, demographic characteristics, and the self-report of visits to mental health and substance abuse treatment in the community. Logistic regression was used to examine how case/comparison group status and lifetime DSM-IV depression at wave 1 were associated with receiving self-help or professional treatment for psychiatric or substance use problems between waves 1 to 3 (an 18 month period). Analyses controlled for income, education, marital status, and lifetime DSM-IV alcohol use disorder (to account for alcohol use disorder that developed in the 14-year follow-up period). An interaction term was used to determine if there was a differential effect of lifetime depression on treatment seeking across case/comparison groups, and predicted probabilities were calculated to determine the extent to which major depression increased the probability of receiving treatment for each case/comparison group.

Results: The interaction between lifetime depression and case/comparison group status was significant, indicating a differential effect of depression on service seeking across case/comparison groups. Depression played a greater role in service seeking for those unaffected by alcohol as compared to those with stable alcohol dependence; the predicted probability for unaffected individuals increased from 5.8% to 53.8% when depression was present, whereas for stable alcoholics the predicted probability increased from 9.2% to 19.5%.

Discussion & Implications: The role of depression in service seeking appears to be more salient in those unaffected by alcohol as compared to those without alcohol dependence. Perhaps these findings suggest that the barriers to treatment seeking for individuals with alcohol problems may also preclude service seeking for co-occurring depression.