Somatic complaints disproportionately contribute to Beck Depression Inventory estimates of depression severity in individuals with multiple chemical sensitivity.

A number of individuals with multiple chemical sensitivity (MCS) are also diagnosed with depression. However, there is content overlap in MCS and symptoms of depression with respect to somatic complaints. The Beck Depression Inventory (BDI) was used to document severity of depressive symptomatology in 42 individuals with MCS. The purpose was to determine the extent to which somatic complaints contributed to the total BDI score. Analysis of cognitive-affective and somatic-performance complaints subscales indicated a significantly higher mean item score on somatic-performance items, relative to cognitive-affective items (t = 6.43, P < 0.05). Consequently, the total BDI score classified a greater percentage (43%) of the sample as moderately depressed than did the cognitive-affective subscale score (29%). An item analysis of the BDI revealed that individuals with MCS tended to endorse more somatic-performance items than did a sample of depressed outpatients. Two alternative interpretations are possible: (a) the BDI total score overestimated severity of depressive symptomatology in this sample, and/or (b) individuals with MCS tended to express depressive symptomatology in terms of somatic complaints. It was recommended that until the etiology of MCS is better understood, caution be used when estimating severity of depressive symptomatology in individuals with MCS when measures include somatic items.