Family relationships and health locus of control as covariables in the evolution of major depressive disorder.

BACKGROUND:In a two-year study, we compared the efficacy of noradrenergic and serotonergic antidepressants with and without the addition of 100 mg acetylsalicylic acid (ASA) in subjects suffering from major depressive disorder (MDD). In this article we examine the influence of the health locus of control, family relationships and personality traits on the progress of MDD. SUBJECTS AND METHODS:40 people with MDD (MDD group) were randomly assigned to the different treatment groups. They were followed in parallel with a group of 20 'healthy' subjects (HG). At the beginning of the study, sociodemographic data were collected, and patients were asked to complete the Multidimensional Health Locus of Control (MHLC) scale, the NEO Five-Factor Inventory (NEO-FFI), and the Family Adaptation and Cohesion Scale (FACES III). During the study subjects were regularly assessed using the Hamilton Depression Scale (HDS), the Short Form Health Survey (SF-12) and the Clinical Global Impression scale (CGI). RESULTS:Regardless of the type of treatment, physical health is the best predictor of variation at two years in the MDD group; 45% of variance is explained by a linear regression model that includes three variables from the MHLC, FACES III and NEO-FFI scales. Similarly, 40% of CGI and 24% of HDS variance is predicted. These explanatory variables are statistically less powerful in the MDD group than the HG group. CONCLUSION:While drug treatment is a determinant in changes on the HDS, CGI and SF12 scales, factors such as family relationships, MHLC or personality are important covariates of these changes. The question remains whether we can influence these covariates to improve the response to antidepressants.