Pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections/pediatric acute-onset neuropsychiatric syndromes vs. pediatric bipolar disorder-A possible connection?

Many studies on the causality of mental illness are currently focusing on the interplay of genetics, environment, inflammatory processes, and immunologic changes. Select diagnostic groups with extant data from some of these domains may provide etiological insight and suggest novel therapeutic paradigms. This article compares and discusses two diagnostic groups with accumulating evidence about the role of genetic, environmental and immunological factors: pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections (PANDAS) and the related pediatric acute-onset neuropsychiatric syndromes (PANS) and pediatric bipolar disorder. These entities are increasingly reported in children and adolescents. Clinical observation and review of the literature suggest similarities between these diagnostic groupings including: early onset; mood dysregulation; irrational and unpredictable temper outbursts; high comorbidity with anxiety disorders (including obsessive compulsive disorder), school refusal, attention deficit hyperactivity disorder, sensory hypersensitivity; unpredictable responses to psychotropic medications and a waxing and waning course that can become chronic with repeated exacerbations. Neurologic symptoms such as tics, rapid jerky movements or other movement abnormalities seen in PANS/PANDAS are not part of the bipolar presentation. A case demonstrating the importance of recognizing both diagnostic groupings is presented. The phenotypic commonalities discussed raise intriguing questions about whether or not illness in a child or adolescent who is genetically predisposed to bipolar disorder can be triggered by infection and subsequent inflammatory and/or immune responses. Additionally, the symptomatic overlap between the two disease groupings, even if not causally related, may have implications for therapy. Treatment of inflammation may ameliorate bipolar symptoms in some patients.