Association and cumulative burden of common mental disorder symptoms with quality of life and functional impairment in primary care

Common mental disorders (CMDs), such as major depressive disorder (MDD), generalized anxiety disorder (GAD), somatic symptom disorder (SSD) and panic disorder (PD), are the most prevalent disorders worldwide. These disorders are mainly addressed in primary care (PC) and are strongly associated with diminished quality of life (QoL) and functioning. This study investigates the individual associations and the cumulative burden of probable MDD, GAD, SSD, and PD with QoL and functioning in PC patients A cross-sectional secondary analysis of baseline data from the PsicAP-CV trial was conducted with a sample of 689 PC patients. Participants completed self-report measures assessing clinical symptoms of CMDs, QoL, and functioning. Pearson correlations and hierarchical multiple linear regression models were utilized to examine the relationships and independent contributions of these clinical symptoms to QoL and functioning. Furthermore, the association between the cumulative burden of algorithm-defined probable CMD classifications and these psychosocial outcomes was analyzed using MANCOVA. Symptoms of the four CMDs were significantly associated with poorer QoL and greater functional impairment across all domains. Regression models showed that the addition of clinical variables significantly increased the variance explained beyond sociodemographic factors. Depressive symptoms showed the strongest independent associations across all QoL and functioning domains. Somatic symptoms significantly predicted physical and environmental QoL, as well as work and social impairment, while panic symptoms independently impacted physical QoL and work-related impairment. MANCOVA analyses indicated that a higher cumulative number of probable CMD classifications was associated with generally poorer QoL and greater functional impairment compared to the zero-classification reference group. These findings underscore that CMDs in PC rarely occur in isolation. The high overlap and the substantial cumulative burden of these conditions highlight the clinical utility of adopting holistic, transdiagnostic approaches to assessment and treatment. Moving beyond single-disorder symptom severity to address shared emotional and physical burden could be key to improving patients’ overall well-being. The study was approved by the Spanish National Scientific Research Ethics Committee, conducted in accordance with the Declaration of Helsinki (EUDRACT: 2013-001955-11) and duly registered (ISRCTN58437086). The original trial was registered in 2013 and a substantial modification of the trial was approved in 2021, with the aim of developing the present research.