Primary care patients' personal illness models for depression: relationship to coping behavior and functional disability.

OBJECTIVE: The applicability and clinical utility of Leventhal et al.'s model of illness cognition were evaluated in depressed primary care patients. The intercorrelations of illness beliefs and the mediational effects of coping behavior on these beliefs were also evaluated. Moderating effects of coping behaviors were explored.
METHODS: Baseline evaluations of demographic information, depression diagnoses, depressive symptom severity, self-reported psychosocial and physical functioning, medical comorbidity, illness beliefs and depression coping strategies were obtained from 191 primary care patients receiving antidepressant medication for the treatment of depression.
RESULTS: Patients' beliefs about depressive symptoms, causes, duration as well as controllability and the consequences of these symptoms are described. Leventhal et al.'s mediational model was partially supported for the outcome of psychosocial functioning. Coping behavior did not mediate the relationship between illness beliefs and physical functioning. The relationships between participants' beliefs about the cause, controllability and duration of depressive symptoms were mediated by the use of behavioral disengagement, venting or self-blame as a strategy to cope with depression. In addition, use of acceptance, religious coping or behavioral disengagement moderated the relationship between beliefs about the cause of depression (i.e., environment or chance or medical illness) and psychosocial functioning.
CONCLUSIONS: Illness models for depression are important determinants of functioning in depressed primary care patients. These beliefs and coping behaviors are potentially modifiable and could be the target of interventions to decrease functional impairment in depressed patients.