Background: We provide new and comprehensive evidence on the evolution of a wide range of patient-reported outcomes (PROs) in the NAMSAL ANRS 12313 trial in Cameroon (2016–2021)—the first randomized comparison of dolutegravir 50 mg (DTG) and low-dose efavirenz (ie, 400 mg; EFV400) in treatment-naive adults living with HIV-1 in sub-Saharan Africa. Methods: We first described the evolution of PROs between baseline and week 192. Then, we used random-effects models to measure the effect of time since the initiation of antiretroviral therapy and the differential effect of DTG versus EFV400 on each PRO, adjusting for clinical, demographic, and socioeconomic factors, while accounting for unobserved heterogeneity and missing data. Results: Among the 613 patients randomized (DTG arm, n = 310; EFV400 arm, n = 303), (1) physical and mental health-related quality of life improved by 13.3% and 6.8%, respectively, (2) the percentage of patients with depression, anxiety, and stress decreased from 23.3%, 23.0%, and 7.7% to 3.1%, 3.5%, and 0.4%, respectively, and (3) the mean number of HIV-related symptoms decreased from 7.2 to 3.0 ( P < 0.001). For most PROs, no significant difference was found between both arms, even when accounting for the effect of DTG on weight gain. Nevertheless, our results suggest smaller improvements in mental health outcomes in the DTG arm, with a 5 percentage point higher adjusted probability of having anxiety at week 192 ( P < 0.01). Conclusions: Although supporting the current World Health Organization guidelines recommending DTG-based and EFV400-based regimens as preferred and alternative first-line antiretroviral therapy, further studies should investigate medium-term mental health outcomes in patients on DTG. Trial Registration: ClinicalTrials.gov: NCT02777229.