The Role of ADHD and Hedonic Capacity in the Clinical Presentation of Treatment-Resistance and Suicidality in Adults with Generalized Anxiety Disorder

Up to 60% of individuals diagnosed with anxiety experience residual symptoms after treatment with standard anxiolytics. Suicide is among the leading causes of death globally. ADHD and generalized anxiety disorder (GAD) are highly comorbid and associated with reduced quality of life and increased risk of self-harm. The aim of this study was to examine predictive factors associated with treatment-resistance and suicidality in patients with GAD.

Patients (N = 160) referred to a tertiary-care psychiatry clinic were screened using MINI International Neuropsychiatric Interview Plus 6.0.0 and psychiatric assessment. Chi-square and logistic regression analyses were conducted to examine predictive clinical features associated with treatment-resistance and suicidality.

Comorbid ADHD was present in 43.7% of treatment-resistant GAD referrals with 91.9% reporting chronic anhedonia. Features predictive of undiagnosed ADHD included sex (65.4% males, p < .031), alcohol (p = .010) and substance dependence/abuse (p = .047), and number of diagnoses (p < .001). Number of current (p < .001) and past intake medications (p < .001), SSRI failure (p < .001), and ADHD (p = .016) predicted treatment-resistance. Chronic anhedonia (p = .042) and alcohol dependence/abuse (p = .025) predicted suicidal ideation, whereas substance abuse was associated with suicide attempt (p = .013).

This study demonstrated undiagnosed ADHD is associated with treatment-resistant GAD and may explain risky behaviors, multiple referral diagnoses, and failed medications. As well, chronic anhedonia may be a prognostic indicator of unrecognized ADHD and suicidality. This signifies the importance of ADHD screening in patients with anhedonia to personalize treatment and reduce self-harm.