Health, wealth, and culture as predominant factors in psychosocial morbidity.

Depression is the most common psychological morbidity in epilepsy, yet this comorbidity is not well understood. Possible explanations for this comorbidity include recurrence of premorbid depression, increased risk for severe epilepsy due to a history of depression, shared risk factors for depression and epilepsy, AED-induced depression in vulnerable individuals, and coping styles in the face of stressors linked to epilepsy. Preexisting vulnerability to depression may contribute to each of these explanations. Vulnerability may arise from the influence of common risk factors, family history of depression, a history of depression before initiation of relevant AEDs, or coping styles and may reflect allostatic load. These exposures may precede the occurrence of epilepsy or follow the onset of epilepsy, in both cases increasing the risk for depression in prevalent epilepsy. Their careful evaluation is vital to identifying people at greatest risk for depression in epilepsy and for informing interventions to prevent the occurrence of this disabling epilepsy comorbidity.