Screening for depression in diabetes using the Beck Depression Inventory

The purpose of this study was to determine the utility of the Beck Depression Inventory (BDI) as a screening tool for major depression in diabetes.

One hundred seventy-two diabetic outpatients (insulin-dependent diabetes mellitus [IDDM] = 59, or non-insulin-dependent diabetes mellitus [NIDDM] = 113) being evaluated for a treatment trial were studied. BDI scores were calculated for the complete 21-item measure as well as for the cognitive (13 items) and somatic (eight items) symptom subgroups. The presence of depression was determined using the National Institute of Mental Health Diagnostic Interview Schedule in accordance with the Diagnostic and Statistical Manual of Mental Disorders (DSM-III-R) criteria. Receiver operating characteristic (ROC) analyses were used to evaluate the performance of the screening test in relation to the diagnostic standard.

Depressed subjects were effectively discriminated from nondepressed subjects by using the full 21-item BDI, the cognitive items alone, or the somatic items alone (p < .001 for each comparison), although the cognitive items were more effective than the somatic items (p < .0005). BDI total scores between 12 and 14 inclusive displayed the best balance between sensitivity (0.90-0.82) and specificity (0.84-0.89), but a cutoff score > or = 16 for the entire 21-item measure exhibited the best balance between sensitivity and positive predictive value when prediction values were extrapolated to a diabetic population with a depression prevalence rate of 20%. This cutoff score would capture > 70% of the patients diagnosed with major depression yet provide > 70% certainty that a person screening positive actually has the psychiatric disorder.

The BDI is an effective screening test for major depression in diabetic patients. Prospective studies are needed to confirm the test's precise performance characteristics in the general clinical setting.