Introduction: ADHD is a common neurodevelopmental disorder and is highly prevalent in adults. It is associated with several negative outcomes, impacting well-being and global functioning. ADHD is highly associated with comorbidities, anxiety disorders being probably the most frequent. The goal of our study is to assess the prevalence of anxiety disorders and their impact in adults with ADHD.

Method: 353 individuals diagnosed with ADHD were recruited. Severity of ADHD was assessed as well as lifetime anxiety disorders and other psychiatric comorbidities. We performed logistic and linear regressions to test the impact of lifetime anxiety disorders on demographic and clinical variables.

Results: More than half of the patients had at least one anxiety disorder. The presence of comorbid anxiety disorders was associated with worse clinical presentation (positive history of suicide attempts, higher disposition toward anger, higher rate of hospitalization and psychotic symptoms) and with a lower level of education.

Conclusion: Anxiety disorders are highly prevalent in ADHD and are associated with higher levels of suicidality and disposition towards anger, more severe clinical presentation and lower functioning. Comorbid anxiety needs to be evaluated and treated by clinicians to limit distress, aggression towards self and others and to improve quality of life.