Affective symptoms and apathy in myotonic dystrophy type 1 a systematic review and meta-analysis

Background: To gain insight into the prevalence of apathy, depression and anxiety symptoms in myotonic dystrophy type 1 (DM1) patients on the basis of a systematic review with a meta-analysis. Methods: One author systematically searched and selected studies from Embase, Medline, PsychInfo and Web of Science (index periods up to August 2018). Data extraction and bias assessment were performed independently by two authors. We calculated (1) a weighted pooled prevalence and (2) weighted pooled standardized mean difference (Hedges’ g) from studies comparing DM1 patients to healthy and/or neuromuscular disease controls separately for symptoms of depression, anxiety and apathy. Results: The pooled prevalences of depression (26 studies, n = 1267 DM1 patients), anxiety (19 studies, n = 896) and apathy (5 studies, n = 428), were 18% (95%CI: 12–25), 16 (95%CI: 13–18) and 55% (95%CI: 55–60), respectively. Effect sizes (Hedges’ g) for depression, anxiety and apathy in DM1 patients compared to healthy controls were 1.04 (95%-CI: 0.71 to 1.37), 0.87 (95%-CI: 0.51 to 1.24) and 1.13 (95%-CI:0.54–1.71). Effect sizes for symptoms of depression, anxiety and apathy were 0.29 (95% CI: -0.12 to 0.70), 0.45 (95%-CI: –0.31 to 1.22) and 1.12 (95%-CI: 0.32–1.93) for DM1 patients versus neuromuscular disease controls. In most analyses, statistical heterogeneity was high. Conclusions: Estimated pooled prevalences of clinically significant levels of symptoms of depression, anxiety and apathy in DM1 are 19, 17 and 55% respectively. Symptoms of depression and anxiety in DM1 may reflect reactive adjustment to progressive impairment and restricted participation similar to other chronic neuromuscular disease. The literature on the prevalence and severity of apathy, although a clinically relevant and characteristic symptom of DM1, is relatively scarce.