[Links between depressive disorders and dependent personality disorders: The important effect of locus of control]

Empirical researches have proved that there are powerful correlations between dependent personality and depression. Different hypotheses were described to conceptualize links between these two entities. The dysfunction of attributive style seems to be linked to dependency and to depression. Interpersonal dependency can be considered to be a mode of adaptation to the external direction of the locus of control. The self-esteem so subjected to the climate of social interactions can lead, by the discontinuity of its protective relations, to the depression. In a coordinated model, this study explores psychopathological aspects between depressive cognition, self-esteem and interpersonal dependency.

This study tries to support the hypothesis that depression and dependency are consequences of an external locus of control, secondary in deterioration of the self-esteem and the main objective is to highlight correlations between external locus of control, interpersonal dependency, hopelessness and depressive affect.

The regrouping of 42 patients in a protocol of psychotherapeutic practices allowed the realization of this retrospective study, multicentric within different hospitals or ambulant psychiatric structures of the agglomeration of Lille, during a period of 6 months. The administration of questionnaires (Beck Depression Inventory/Dependent Personality Questionnaire by Tyrer, translated by Loas/Hopelessness Scale by Beck/Powerful others and Chance Scale [IPC] of Levenson, translated by Loas) was included into clinical practice.

The main results indicate that external locus of control "powerful others" is significantly correlated with pathological dependency (P<0.0001), depression (P<0.0001) and hopelessness (P=0.02). In addition, the pathological dependency seems to be correlated with external locus "chance" (P<0.05) and external locus "powerful others" (P<0.0001).

We explored in this study the powerful links joining pathological dependency with depression. These correlations confirm and specify data found in literature. This work is in favor of a conception of external locus of control as a psychopathologic component between depression and dependent personality. This cognitive aspect manifests vulnerability in the depression of the patients suffering from pathological dependency. Also, the place of external locus of control ("powerful others" and "chance") seems to be a cognitive dimension more pathogenic than the internal locus of control. It will be necessary to investigate other psychopathological dimensions such as self-esteem in a longitudinal report. Without neglecting neurobiological vulnerability in depression, it is pertinent to identify this cognitive fragility to optimize the psychotherapies.