In primary care, individuals with a history of depression often opt for maintenance antidepressant medication as recommended by the National Institute for Health and Care Excellence (NICE) guidance for up to 2 years to prevent depression relapse (NICE, 2022). When considering discontinuing maintenance antidepressants, it is important to assess the risk of potential relapse (Maund et al., 2019). Currently, there is limited knowledge about the clinical risk factors that may increase vulnerability to relapse among individuals in primary care. Some evidence suggests that factors such as the number of previous depression episodes (Conradi et al., 2008), residual depression symptoms, and comorbid anxiety (Gopinath et al., 2007) are linked to a higher risk of relapse in this population.
To address this gap in knowledge, Duffy and colleagues (2023) conducted a study to identify clinical factors associated with the risk of depression relapse in individuals considering discontinuation of long-term maintenance antidepressant treatment. The study utilized data from the ANTLER trial, a double-blind, randomized controlled trial, where participants were randomized to either continue or taper their antidepressant use over 2 months. Cox proportional hazards modeling was employed to assess the time to relapse, with relapse defined as the reappearance of depressive symptoms.
The results of the study indicated that individuals with a greater number of previous depressive episodes, higher residual depression symptoms, and a younger age of depression onset were at an increased risk of relapse. Specifically, individuals with more than 5 previous episodes of depression had a 57% increased risk of relapse, while a 1-point increase on the PHQ-9 scale was associated with a 6% greater chance of relapse. Additionally, a younger age of depression onset (<40 years) was linked to an increased risk of relapse. These findings suggest that clinicians should consider these clinical factors when assessing the risks of relapse in individuals on long-term maintenance antidepressants who are considering discontinuation. However, the study also highlights the need for further research to explore additional factors that may influence the risk of depression relapse in this population, such as co-morbid physical and mental health conditions, previous psychological therapies received, and sociodemographic factors like ethnic diversity, employment, housing, and income. Overall, this study provides valuable insights into the clinical factors associated with depression relapse in individuals on long-term maintenance antidepressants, but emphasizes the importance of continued research to fully understand and address the complexities of relapse risk in this population.
