The use of stimulants and atomoxetine in adults with comorbid ADHD and bipolar disorder.

INTRODUCTION: Attention deficit/hyperactivity disorder (ADHD) persists into adulthood in about 50% of the affected children, with high rates of comorbidity with bipolar disorder (BD). Stimulants and atomoxetine (ATX) are effective treatments for ADHD, but their use in adults with comorbid BD (ADHD-BD) has not been extensively studied and may be problematic. AREAS COVERED: The aim of the paper is to summarize the available literature regarding the use of these medications in ADHD-BD adult patients. Results of randomized-controlled and open-label trials, case reports, and case series are reviewed. We also reviewed data relative to some specific issues of this comorbidity in adults, especially substance use disorder, malingering, and stimulants misuse. EXPERT OPINION: ADHD-BD may be associated with more severe symptoms, course, and worst outcome of both conditions. The frequent coexistence with alcohol and substance abuse may further complicate treatment management. Stimulants are the most effective medications for ADHD, but their use may be contraindicated in the presence of a comorbid drug abuse or in patients that simulate or exaggerate ADHD symptoms in order to obtain stimulants for diversion or abuse. ATX may be effective in the treatment of ADHD symptoms in BD patients, with a modestly increased risk of (hypo)manic switches and destabilization of the mood disorder when utilized in association with mood stabilizers. In the majority of the cases, a hierarchical approach is desirable, with mood stabilization preceding the treatment of ADHD symptoms. Although systematic trials on the use of stimulants and ATX in ADHD-BD comorbidity in adulthood are necessary, both treatments should be considered possible options to be carefully evaluated once the patient has been stabilized.