Dissecting the association between long COVID and depressive symptoms in a nationally representative population from France.

Objective: Depressive symptoms may overlap with those of long COVID. This cross-sectional study aims to compare the prevalence of depressive symptoms among individuals infected with SARS-CoV-2 with versus without long COVID and to explore specific associations with each of the nine core symptoms of major depression.

Methods: Data regarding age, gender, SARS-CoV-2 infections, current symptoms, their date of onset, impact on daily functioning, and consideration of alternative diagnoses were collected through phone interviews between September and December 2022 in a nationally representative sample of adults aged ≥18. Data on chronic health conditions and depressive symptoms (PHQ-9) were collected online in infected participants with or without long COVID, according to the WHO definition of the post-COVID-19 condition.

Results: Among 1247 participants (mean age (SD): 48.3 (14.3) years, 53.3 % of women), 12.8 % had long COVID and 87.2 % experienced SARS-CoV-2 infection at least 3 months prior to the survey without long COVID. Participant with long COVID were four-fold more likely to have a PHQ-9 score ≥ 10 than those without (44.0 % versus 11.1 %). Three symptoms out of nine were independently associated with long COVID: little interest or pleasure (aOR [95 % CI]: 2.01 [1.03-3.92]), feeling tired or having little energy (1.92 [1.10-3.33]), and poor attention/concentration (2.02 [1.03-3.96]).

Conclusion: Clinicians should screen patients with long COVID for major depression but associations with specific depressive symptoms suggest some clinical overlap. Future studies should consider the course of each depressive symptom separately and focus on those less prone to overlap with symptoms of long COVID.