Discussion
anxiety, psychiatric, depressive symptoms, depression, adjustment disorders
DISORDER, REMISSION, PCP
In this RCT of over 500 primary care patients with symptoms of depression, anxiety, or at-risk drinking, compared with eUC, a novel, low-cost, transdiagnostic tCC intervention delivered by lay providers did not result in a larger improvement in depression symptoms in those presenting with depression at baseline or in health-related quality of life and functioning in the whole sample. In those presenting with anxiety, tCC yielded a larger improvement in anxiety symptoms. While tCC did not affect the proportion of participants who had transitioned from at-risk drinking to safe drinking at the end of the 12-month study, it was associated with a faster transition. Participants randomized to tCC were more likely to have antidepressants initiated and to receive adequate antidepressant treatment than those randomized to eUC. These findings suggest that tCC delivered by lay providers is feasible in primary care and may benefit some patients with anxiety or at-risk drinking. These findings are also relevant in the context of the COVID-19 pandemic, which has led to a higher prevalence of anxiety symptoms and substance misuse and a rapid increase in virtual health care.Improvement in depressive symptoms and rates of depression response or remission were high in both groups; contrary to our hypotheses, they were not significantly different in the tCC or eUC groups. This is despite the fact that those receiving tCC were more likely to be prescribed an adequate antidepressant trial. This finding is inconsistent with similar previous studies.The positive effect of our active intervention on anxiety symptoms is consistent with a previous trial of a telephone-based tCC for 329 primary care patients with anxietySimilarly, in a recent large RCT in primary care patients with depression or anxiety, sertraline was superior to placebo for anxiety symptoms but not depressive symptoms.Our results also add to the limited literature on CC interventions for alcohol use disorder. Two published RCTs of (face-to-face) CC for alcohol use disorder have reported conflicting results.Our study has both strengths and limitations. Although we only randomized half of the planned sample, the relatively large sample size and high retention rates (68.5% overall) provided sufficient power to detect clinically meaningful differences. Selecting participants based on referrals from their PCP and their scores on the PHQ-9 or GAD-7 rather than formal psychiatric diagnoses has some pragmatic advantage (i.e., it better reflects primary care practice). However, it may have resulted in the inclusion of participants with adjustment disorders or subsyndromal depression, both of which have been shown to resolve with the passing of time or placebo treatment,In conclusion, the findings of our RCT, taken together with the results of other CC trials, support the feasibility of implementing transdiagnostic tCC delivered by lay providers in primary care. However, while patients with anxiety or at-risk drinking benefitted from tCC compared to eUC, this was not the case for those with depression. This negative result goes against our hypothesis that the crucial “ingredient” of the active intervention would be the MHT. Given the marked improvement in depressive symptoms with both tCC and eUC, future studies of CC for depression need to assess the benefits and cost-effectiveness of its specific components, in particular, MBC.