The Influence of Somatic Symptoms on Beck Depression Inventory Scores in Hospitalized Postmyocardial Infarction Patients

Objective: The Beck Depression Inventory (BDI) has been used more than any other self-report questionnaire in research on depression in cardiovascular disease. However, no studies have examined whether BDI scores may be influenced by somatic symptoms common after myocardial infarction (MI) that may overlap with symptoms of depression. The objective of this study was to examine whether BDI scores of post-MI patients may be influenced by somatic symptoms that commonly occur after MI, but may not be related to depression. Method: Post-MI patients and psychiatric outpatients were matched on BDI cognitive-affective symptom scores, sex, and age, and their BDI somatic symptom scores were compared using independent samples t tests. Results: Somatic symptoms accounted for 57% of BDI total scores for 296 post-MI patients (mean total BDI = 8.8), compared with 50% for 296 matched psychiatric outpatients (mean total BDI = 7.6). Overall, BDI somatic scores of post-MI patients were 1.3 points higher than for psychiatric outpatients (95% CI 0.68 to 1.82; P < 0.001), equivalent to 14% of total scores of post-MI patients. Conclusions: The relative influence of somatic symptoms on BDI total scores was higher for post-MI patients than for psychiatric outpatients matched on cognitive-affective scores, sex, and age. This finding stands in contrast to that from a previous study that used similar methods and sample comparisons and found that post-MI and psychiatric outpatients did not differ in their endorsement of somatic symptoms on the BDI-II. The BDI-II may be preferable to the BDI in post-MI patients.