Background <p>Psychological therapies have been shown to reduce sickness absence (SA) among individuals with common mental disorders (CMDs) in clinical trials, but their real-world impact is unclear. To address these knowledge gaps, we compared the likelihood of receiving publicly-financed SA compensation among individuals with CMDs who received at least one session of systematic psychological therapy in primary care and individuals with CMDs who did not receive these treatments.</p> Methods <p>Primary healthcare registers were used to identify individuals with CMDs in Region Stockholm who had received psychological therapies (<i>N</i> = 12,167) and untreated controls (<i>N</i> = 40,517). SA was measured at six-monthly intervals in the two years before and after treatment commencement. Crude and inverse probability weighted (IPW) generalised estimating equation (GEE) models were used to compare the likelihood of having &gt; 14 net SA days (primary outcome) and &gt; 30 and &gt; 90 days (secondary outcomes) at each six-month interval to the period preceding treatment commencement (t0). Crude and IPW models were performed in the treated and control groups separately, with effects at each time-point compared via the ratio of odds ratios (ROR).</p> Results <p>In the crude model, the treated group showed significantly greater reductions in the likelihood of having &gt; 14 net SA days at t12, t18, and t24 compared to the control group (ROR: 0.82, 0.80, and 0.79, respectively). However, in the IPW models, the likelihood of receiving &gt; 14 net SA days at t6 relative to t0 was significantly higher in the treated group (ROR: 1.33, 95% CI: 1.25–1.40) with no group differences at t12, t18, or t24. Moreover, the treated group fared significantly worse than the control group in IPW models examining &gt; 30 and &gt; 90 net SA days. In sensitivity analyses, individuals receiving 1–2 sessions showed a greater reduction in the likelihood of having the primary outcome relative to the control group at t12, t18, and t24, whilst those receiving greater doses of psychological therapy (6–12 and &gt; 12 sessions) had a significantly higher likelihood of SA at these timepoints.</p> Conclusions <p>Our findings tentatively suggest that psychological therapies delivered in primary care are not associated with a reduction in the likelihood of receiving sick leave in people with CMDs. However, due to the possibility of unmeasured confounders, our findings cannot support causal inferences. Further studies in real-world settings are needed to investigate whether treatment-related factors (e.g., therapeutic focus, quality, and fidelity) modify the effect of primary-care delivered psychological therapies on SA outcomes among people with CMDs.</p> Clinical trial number <p>Not applicable.</p>