The Association Between Depressive Symptoms and Limitations in Physical Functioning

Depression, a prevalent mood disorder, is often accompanied by considerable functional impairment. Its relationship with specific physical functioning domains and potential variations by symptom type or sex, however, has not been fully clarified. This study investigates these associations, paying particular attention to overall severity, sex differences, and cognitive-affective versus somatic symptom dimensions.

Data were drawn from 31,336 adults who participated in the 2005-2018 National Health and Nutrition Examination Survey (NHANES). Depressive symptoms were measured using the Mental Health-Depression Screener (Patient Health Questionnaire [PHQ-9]), while functional outcomes were based on the Physical Functioning questionnaire (PFQ). Multivariable logistic regression models were applied to examine associations.

Of all participants, 2534 (7.09%) met criteria for depressive symptoms. These individuals demonstrated markedly greater odds of functional limitations across multiple domains. The strongest association was observed for limitations in leisure and social activities (LSAs; aOR = 8.04; 95% CI = 6.68-9.67), while the weakest was for lower extremity mobility (LEM; aOR = 4.51; 95% CI = 3.53-5.76). Each incremental increase in PHQ-9 score was linked to higher odds of limitations, including 21% greater odds for LSAs (95% CI = 1.19-1.24) and 16% for LEM (95% CI = 1.14-1.19). Sex-stratified analyses suggested that females reported fewer impairments in activities of daily living (ADLs), instrumental ADLs (IADLs), LEM, and general physical activities (GPAs) than males. Cognitive-affective and somatic subscales both showed the strongest associations with LSAs (aOR = 1.35; 95% CI = 1.30-1.40; and aOR = 1.40; 95% CI = 1.37-1.44, respectively) and the weakest with LEM (aOR = 1.25; 95% CI = 1.21-1.29; and aOR = 1.32; 95% CI = 1.27-1.37, respectively).

Depressive symptoms are consistently and strongly related to physical functioning difficulties, with variations across symptom domains and sex. Future studies should explore underlying mechanisms and validate these findings.