Patients with persistent depressive disorder (PDD) have worse mental and physical health outcomes compared with patients with nonchronic major depressive disorder (NCMDD), according to study results published in BMC Psychiatry.
In the study, researchers from Germany obtained patient data between 2009 and 2012 from the mental health module of the German Health Interview and Examination Survey for Adults (DEGS1-MH; n=4483; 49.1% men; mean age, 48 years), as well as a clinical sample of inpatients at Charité – Universtätsmedizin Berlin between 2018 and 2019 (n=45; 53.3% men; mean age, 47.1 years). The researchers assessed depression characteristics in these patients, including depression onset, self-classified course, suicidality, comorbid mental disorders, treatment history, and current depressive symptoms on the Patient Health Questionnaire-9.
Patients with PDD were compared with patients with NCMDD in the DEGS1-MH in terms of health-related quality of life (Short Form Health Survey-36), chronic somatic conditions, number of sick days in the past 12 months, or days with limitations in normal activities of daily life in the past 4 weeks, and health service utilization in the past 12 months.
More patients with PDD in the clinical sample experienced depression onset before age 21 years compared with cases of PDD and NCMDD in the DEGS1-MH sample (73.3% vs 24.7% vs 32.2%, respectively). In addition, patients with PDD in the clinical sample demonstrated more suicidality than all patients in the DEGS1-MH sample (95.5% vs 86.2-86.4%). A higher percentage of patients with PDD had a persistent depressive course compared with DEGS1-MH PDD and NCMDD cases (50.0% vs 24.6% vs. 2.0%).
In the DESGS1-MH cohort, PDD was associated with worse outcomes compared with NCMDD for somatic comorbidity (risk of having ≥2 comorbid conditions, 26.2% vs 15.6%, respectively; relative risk ratio, 3.2; P =.004), mental health-related quality of life (34.5 vs 43.8; P <.001), and mean number of days with activity limitations due to mental health problems (5.4 vs 2.4 days; incidence rate ratio, 2.6; P <.001). Overall, patients with PDD compared with patients with NCMDD also more often reported fair or poor self-rated health (36.8% vs 20.4%; odds ratio, 2.0; P =.041).
A study limitation was the small number of PDD cases, which may have reduced statistical power, as well as the accuracy of the frequency and mean estimates. However, the researchers wrote that these findings “highlight the need to further reduce barriers to accessing mental health care, improve awareness of different depression courses among health professionals, and implement specific treatment concepts for chronic depression.”
Nübel J, Guhn A, Mullender S, Le HD, Cohrdes C, Kohler S. Persistent depressive disorder across the adult lifespan: results from clinical and population-based surveys in Germany. BMC Psychiatry. 2020;20(1):58.