Background
People with HIV (PHW) are at greater risk of depression than the general population. Insight into the time-to-treatment-response and predictors of response to psychotherapy may improve implementation in primary care.

Methods
We assessed depression treatment response among 80 participants in a trial of cognitive-behavioral therapy for adherence and depression (CBT-AD) for PWH with MDD and suboptimal antiretroviral therapy (ART) adherence. Participants self-reported depressive symptoms (CESsingle bondD) at each therapy session. Clinicians assessed participants' depression (HAMsingle bondD), along with potential predictors of response, every four months for one year. Latent class analyses examined classes of responders for the active and the post-treatment phases. Regression analyses identified predictors of class membership for each phase.

Results
During the active treatment phase (CESsingle bondD) we identified an early response (at session 2 and with continued trajectory of improvement) and a non-response group. There were also two classes during post-treatment (HAM-D): early responders (4-month) and late responders (12-month). Distress aversion was associated with lower likelihood of early response to CBT-AD (aOR = 0.74, 95%CI[0.56–0.90], p = .009), and social support was associated with increased likelihood of early response (aOR = 2.24, 95%CI[1.07–5.46], p = .045).

Limitations
Self-reported depression during the treatment phase may have resulted from social desirability bias.

Conclusions
Most participants responded to CBT-AD early during treatment (89 %) and had sustained improvements in depression by 4 months (80 %). Distress aversion was a risk factor for late response, and social support was protective. Future research is needed to assess the optimal dose of CBT-AD in resource limited settings.