Does presence of metabolic syndrome impact anxiety and depressive disorder screening results in middle aged and elderly individuals? A population based study

Background: Depressive and anxiety disorders are common in primary care setting but often remain undiagnosed. Metabolic syndrome (MetS) is also prevalent in the general population and can impair recognition of common mental disorders due to significant co-morbidity and overlap with psychiatric symptoms included in self-reported depression/anxiety screening tools. We investigated if MetS has an impact on the accuracy of current major depressive disorder (MDD) and generalized anxiety disorder (GAD) screening results using the Hospital Anxiety and Depression scale (HADS). Methods: A total of 1115 (562 men; mean age 62.0 +/- 9.6 years) individuals of 45+ years of age were randomly selected from the general population and evaluated for current MetS; depressive and anxiety symptoms (HADS); and current MDD and GAD (Mini International Neuropsychiatric Interview [MINI]). Results: The MetS was diagnosed in 34.4% of the study participants. Current MDD and GAD were more common in individuals with MetS relative to individuals without MetS (25.3% vs 14.2%, respectively, p < 0.001; and 30.2% vs 20.9%, respectively, p < 0.001). The ROC analyses demonstrated that optimal thresholds of the HADS-Depression subscale for current MDE were >= 9 in individuals with MetS (sensitivity >= 87%, specificity = 73% and PPV = 52%) and >= 8 in individuals without MetS (sensitivity = 81%, specificity = 78% and PPV = 38%). At threshold of = 9 the HADS-Anxiety subscale demonstrated optimal psychometric properties for current GAD screening in individuals with MetS (sensitivity = 91%, specificity = 85% and PPV = 72%) and without MetS (sensitivity = 84%, specificity = 83% and PPV = 56%). Conclusions: The HADS is a reliable screening tool for current MDE and GAD in middle aged and elderly population with and without MetS. Optimal thresholds of the HADS-Depression subscale for current MDD is >= 9 for individuals with MetS and >= 8 - without MetS. Optimal threshold of the HADS-Anxiety subscale is >= 9 for current GAD in individuals with and without MetS. The presence of MetS should be considered when interpreting depression screening results.