Bipolar disorder in children is controversial. It didn't use to be diagnosed as often as it is now, especially in the U.S., and more atypical symptosm are suggested to be bipolar. In the journal Child and Adolescent Mental Health, Boris Birmaher reviewed the literature surrounding this controversy. It's an interesting article, viewing the controversy from all sides.
Birmaher starts by describing the diffiuclties diagnosing manic, hypomanic and depressive episodes in children and adolescents. Particularly, it is hard to distinguish symptoms of (hypo)mania from normal episodes of increased activity or from ADHD. Depressed symptoms are also hard to diagnose because children do not always feel or look depressed all the time. Adolescents experiece more atypical symptoms (increased sleep and appetite and weight gain) than adults do. Birmaher discusses whether onepisodic mania can be seen as bipolar.
He fortunately also shreds the idea that irritability only is bipolar. It isn't. In fact, it is not severe mood dysregulation (also known as disruptive mood dysregulation disorder) eitehr, which surprised me. Irritability only is more indicative of ADHD or disruptive behavior disorders than of bipolar or SMD. Elation only, also, is not common in childhood or adolescent bipolar. More likely, patients experience both irritability and mood elation.
Birmaher is quite clear that pediatric bipolar disorder exists. The prevalence is around 2%, with just over 1% of children and adolescents presenting with bipolar I. For some perspective, Levorich et al. (2007) show that as many as half of adult bipolar patients in their study reported onset in childhood (14%) or adolescence (36%).
Birmaher is not a bipolar proponent, in the sense that he thinks atypical symptoms warrant a diagnosis of BP. He makes it quite clear that more research is needed into the risk factors for converting from atypical or subsyndromal bipolar-like symptoms into full-blown bipolar in children and adolescents. It looks like family history of bipolar is one such factor. Levorich et al (2007) found that, the earlier the onset of bipolar disorder, the more likely the patients were to have a parental history of bipolar or depressive disorders.
Levorich et al. (2007) particularly studied prognosis in adults with bipolar disorder, comparing those with (retrospectively reported) childhood or adolescent onset bipolar to those with onset in adulthood. They found that, the earlier the onset of the disorder, the more likely patients were to suffer from dysphoric (irritable) rather than euphoric mania and the more likely they were to have comorbid anxiety and drug abuse. In addition, the researchers tracked all participants' mood over a year's period. This showed that those with early onset bipolar had more depressed episodes, more severe manic and depressive symptoms and fewer good days in a year than those whose bipolar started in adulthood. For these and other reasons, Levorich et al. advocate an active ruling in or outo f bipolar d isorder in children and adolescents, rather than it being considered a last resort diagnosis.
References
Birmaher B (2013), Bipolar Disorder in Children and Adolescents. Child and Adolescent Mental Health, 18: 140-148. DOI: 10.1111/camh.12021.
Levorich GS, Post RM, Keck PE, Altshuler LL, Frye MA, Kupka RW, Nolen WA, Suppes T, McElroy SL, Grunze H, Denicoff K, Moravec MKM, & Luckenbaugh D (2007), The Poor Prognosis of Childhood-Onset Bipolar Disorder. Journal of Pediatrics, the, 150(5):485-490. DOI: 10.1016/j.jpeds.2006.10.070.
