A prospective study of mental health outcomes in morbidly obese patients

Aim: To determine if co-morbidities have an effect on mood in a cohort of morbidly obese patients.
Methods: Sequential linear regression analysis conducted on health and demographic data, using two validated anxiety/depression scales combined [Patient Health Questionnaire (PHQ-9) and Generalized Anxiety Disorder (GAD-7)] as the primary outcome.
Results: Complete outcome data was recorded on 410 patients. 211 (51.4%) had 1 or 2 reported co-morbidities; of which hypertension and anxiety/depression were the most common. One hundred and seven patients (26.4%) were recorded as having diabetes. The outcome measures of PHQ-9 and GAD-7 were found to be strongly and significantly correlated (r=0.822; p<0.001); hence analysis was conducted on a combined outcome. Occurrence of arthritis and anxiety/depression were both statistically significant at the 5% significance level (p=0.049 for arthritis; p<0.001 for anxiety/depression), with the presence of both conditions being associated with lower functionality. Age appeared to show some substantive association with the outcome (p=0.069); with increasing age being associated with slightly improved functionality. BMI, gender and the presence of other co-morbidities, including diabetes, did not exhibit any substantive relationship with the outcome measure.
Summary: There is insufficient evidence to conclude that either BMI, gender or diabetes affect scores measured on the combined PHQ-9/GAD-7 outcome. Of the various co-morbidities reported by patients, arthritis and, particularly, reported anxiety/depression have the greatest effect on combined scale scores.