OBJECTIVE: Obesity and depression are associated with somatic complaints that may complicate the measurement of depression in obese individuals. The Beck Depression Inventory-II (BDI-II) and the Hamilton Rating Scale for Depression (HRSD) are frequently used to measure depression severity. The BDI-II and HRSD's ability to measure depression severity may be compromised in those with obesity, to the extent that scores on their somatic items stem more from obesity than from depression. This study examined the: 1) internal consistency of the BDI-II and HRSD among obese women who varied in depressive symptomatology and 2) total and item-level change in the measures among participants who met the criteria for depression remission at 6-months.

METHODS: Data were from a randomized controlled trial of obese women with depression who received either behavioral activation for depression followed by a lifestyle intervention or a lifestyle intervention with attention control.

RESULTS: At screening (n=355), internal consistency was strong for the BDI-II (alpha=0.89), but moderate for the HRSD (alpha=0.67). Among the participants who met the criteria for depression remission following treatment (n=115), every BDI-II item showed significant change at 6-months. In contrast, three HRSD items did not significantly change: the anxiety-somatic (p=0.063), somatic symptoms-gastrointestinal (p=1.000) and loss of weight (p=0.319) items.

CONCLUSION: The BDI-II may be more reliable and sensitive to change than the HRSD in obese women with comorbid depression. Intervention studies involving obese, depressed women should consider these findings in selecting depression outcome measures.