Section on Mood Dysregulation and Neuroscience (SMDN)
SMDN focuses primarily on discovering the brain mechanisms mediating chronic, severe irritability, and on using those discoveries to generate new treatments. Our studies of irritability include both youth with the DSM-5 diagnosis of Disruptive Mood Dysregulation Disorder (DMDD) and those whose irritability is more mild but still impairing, such as those with attention deficit hyperactivity disorder (ADHD). Our major tool for studying brain mechanisms is functional magnetic resonance imaging (fMRI). This fMRI neuroimaging work provides information that guides the development of novel treatments, which we then test. Thus, we conduct pathophysiological research, based on systems neuroscience principles and techniques, with the goal of informing novel treatment development.
Our focus on irritability arose in response to questions about whether severely impairing irritability, without distinct manic episodes, should be considered to be a form of pediatric BD. To facilitate research on this question, we defined a syndrome called severe mood dysregulation (SMD); this research informed the DSM-5 discussions regarding DMDD. Our brain-based research, in concert with longitudinal and family studies, support the conclusion that, while both BD and chronic irritability are both very impairing in youth, they are not manifestations of the same illness. That is, relatively few youth with severe irritability develop BD in adulthood. This conclusion has significant treatment implications, in that first-line treatments for BD and DMDD are likely to differ.
Indeed, since DMDD is a new diagnosis, few treatments have been tested. Much of our research is designed to elucidate the brain mechanisms mediating irritability, both in DMDD, where it is particularly severe, and in anxiety disorders, depression, and attention deficit hyperactivity disorder, where irritability is also common. Careful clinical phenotyping is a hallmark of our work. As noted above, our work on brain mechanisms centers on fMRI studies, although we also use other neuroimaging techniques, as well as ecological momentary assessment, eye tracking, behavioral testing, and other approaches. The tasks that we use in the fMRI scanner focus on responses to frustration, face emotion processing, cognitive control, and attentional mechanisms. Based on these and related studies, much of our current work focuses on testing several novel psychological treatments, including computer-based treatments and a cognitive behavioral therapy that uses exposure techniques and target irritability specifically.