Adult ADHD and comorbid depressive disorders: diagnostic challenges and treatment options.

Attention-deficit/hyperactivity disorder (ADHD) and major depressive disorder (MDD) are separately common mental health conditions that can have an adverse effect on a patient's quality of life if left untreated. These disorders frequently co-occur with one another, which can lead to increased patient suffering and diagnostic challenges for the treating clinician. In the United States adult population, epidemiological data show that the prevalence rate for MDD is 6.7%, while the ADHD prevalence rate in US adults is 4.4%. This epidemiological data represents the general population and likely underestimates the prevalence rates in clinic or practice patients. Examining the concurrent comorbid rate, if a patient has MDD, the likelihood of that patient also having ADHD is 18.6%; if the patient has ADHD, the likelihood of that patient having comorbid MDD is 9.4%. If the patient has dysthymia, the comorbid rate of ADHD is 12.8%, while those adults with ADHD have a comorbid rate of dysthymia of 22.6%.