Attention deficit hyperactivity disorder (ADHD) is one of the most common neurobehavioral disorders, affecting 5–۷% of school children worldwide [1]. In the USA, up to 11% of youth have been diagnosed with ADHD and over 5% of school children have been prescribed ADHD medication [2]. More money is spent on ADHD care than any other childhood condition, except newborn care [3] Many children with ADHD also meet criteria for additional behavioral health disorders, with mood and anxiety disorders being some of the most commonly occurring comorbidities [4–۶]. Up to 40% of children with ADHD may meet criteria for a mood disorder over their lifetime [4, 5]. In the largest clinical trial of ADHD to date, the Multimodal Treatment Study of ADHD, 6% of participants met criteria for mood disorders at baseline [6]. In clinical samples of depressed adolescents, 13.7% had comorbid ADHD [7]. In addition, childhood ADHD increases the rate for depression in young adulthood, which is mediated by persistent ADHD symptoms and associated impairment [8]. The combination of ADHD, depression, and a disruptive behavior disorder [either oppositional-defiant disorder (ODD) or conduct disorder] appreciably increases the risk for attempted and completed suicide [9, 10]. When comorbid, ADHD typically onsets first suggesting that management of ADHD may help to reduce the risk of future depression [11, 12]. Over the past two decades, there has been appreciable controversy about the association between bipolar disorder and ADHD. When severe persistent irritability is interpreted as a symptom of mania, multiple studies reported elevated rates of bipolar disorder in children with ADHD [13–۱۵]. The labels of severe mood dysregulation (SMD) and then disruptive mood dysregulation disorder (DMDD) [16] were created to describe children with severe persistent irritability and frequent temper outbursts but who did not meet full diagnostic criteria for bipolar disorder. It remains a point of debate if severe persistent irritability is a meaningfully distinct diagnostic entity [17, 18]. It has now been established that chronic irritability, even when severe, is not a meaningful risk factor for mania [19–۲۱], but there is increasing evidence that this presentation is in association with a wide range of impairments that merits intervention [22– ۲۴]. Poor frustration tolerance has been suggested to be a key mechanism underlying the relationship between ADHD and depression [25].