Anhedonia as a transdiagnostic symptom across psychological disorders: a network approach.

BACKGROUND: Anhedonia is apparent in different mental disorders and is suggested to be related to dysfunctions in the reward system and/or affect regulation. It may hence be a common underlying feature associated with symptom severity of mental disorders. METHODS: We constructed a cross-sectional graphical Least Absolute Shrinkage and Selection Operator (LASSO) network and a relative importance network to estimate the relationships between anhedonia severity and the severity of symptom clusters of major depressive disorder (MDD), anxiety sensitivity (AS), attention-deficit hyperactivity disorder (ADHD), and autism spectrum disorder (ASD) in a sample of Dutch adult psychiatric patients (N = 557). RESULTS: Both these networks revealed anhedonia severity and depression symptom severity as central to the network. Results suggest that anhedonia severity may be predictive of the severity of symptom clusters of MDD, AS, ADHD, and ASD. MDD symptom severity may be predictive of AS and ADHD symptom severity. CONCLUSIONS: The results suggest that anhedonia may serve as a common underlying transdiagnostic psychopathology feature, predictive of the severity of symptom clusters of depression, AS, ADHD, and ASD. Thus, anhedonia may be associated with the high comorbidity between these symptom clusters and disorders. If our results will be replicated in future studies, it is recommended for clinicians to be more vigilant about screening for anhedonia and/or depression severity in individuals diagnosed with an anxiety disorder, ADHD and/or ASD.

Comorbid depression and treatment of anxiety disorders, OCD, and PTSD: Diagnosis versus severity.

BACKGROUND: Although anxiety and depression are highly comorbid disorders, it remains unclear whether and how a concurrent depression affects the outcome of anxiety treatment. METHOD: Using anonymized routine outcome monitoring (ROM) data of 740 patients having received specialized treatment for an anxiety disorder, OCD, or PTSD, this study investigates whether a comorbid diagnosis of depression and/or self-reported depression severity levels relate to the patients' improvement following anxiety treatment. RESULTS: The results show that both the patients with and those without comorbid depression had profited similarly from the anxiety, OCD, or PTSD treatment, regardless of whether depression was merely diagnosed prior to treatment or based on self-reported severity (and assuming a smallest effect size of interest of d = 0.35/r = .2). Importantly, the post-treatment reductions in self-reported depressive symptoms were strongly and positively related to the reductions in self-reported anxiety symptoms and disorder-related disability. LIMITATIONS: Causal inferences cannot be made due to the retrospective cross-sectional design. CONCLUSIONS: The outcomes obtained in a naturalistic patient sample support current treatment guidelines recommending evidence-based treatment for anxiety disorders, OCD, and PTSD in patients with and without a comorbid depression. Future treatment studies are recommended for investigate the (bi)directionality of anxiety and depressive symptoms throughout treatment.