Long-term Outcomes for Childhood-Onset Disorders: Bipolar Disorder
This week we’ll be summarizing the research on long-term outcomes for four childhood-onset illnesses: bipolar disorder, unipolar depression, attention-deficit hyperactivity disorder (ADHD), and anxiety disorder. The information comes from a symposium at the 2012 meeting of the American Academy of Child and Adolescent Psychiatry (AACAP).
Course of Childhood Onset Bipolar Disorder
At the AACAP meeting, researcher Boris Birmaher discussed the considerable differences in presentations of bipolar disorder in childhood versus in adolescence. In childhood there appeared to be a more sub-syndromal symptoms or diagnoses of bipolar not otherwise specified (BP-NOS). There were more mixed symptoms, more hallucinations, worse course of illness, more comorbidities with ADHD and oppositional defiant disorder, and more separation anxiety disorder. In contrast, in adolescence there were more diagnoses of bipolar I and bipolar II, major depression, mania with elation and grandiosity, substance abuse, and conduct disorder.
Birmaher reported that while most children with early-onset mania recovered within two years, roughly 80% experienced recurrences over the next two to five years. Over a follow-up period of four years, 30% remained euthymic, 40% had continuing substantial symptoms, and 20% remained seriously ill. Birmaher’s data indicate that those with childhood-onset bipolar illness remained symptomatic during 60% of the follow-up period.
Predictors of a more difficult outcome included an early onset, a BP-NOS presentation, longer duration of illness, any comorbid illness, lower socioeconomic status, and a family history of bipolar disorder in first-degree relatives. Birmaher reported that these data in childhood-onset mania were consistent with earlier research by Judd and colleagues in a longitudinal follow-up study of adult patients with bipolar disorder. However, there were three major differences. The proportion of time well was lower in children (41.1%) than in adults (52.7%). Time in mixed episodes or rapid cycling was higher in childhood-onset bipolar disorder (28.9%) than in adults (5.9%). Rapid changes in polarity were also more common in children (15.7% ) than in adults (3.5%).
Birmaher and colleagues initially found that about 40% of children with BP-NOS converted to bipolar I or II upon follow-up. However, after longer follow-up, they have found that 50% of those with BP-NOS convert to bipolar I or bipolar II. Roughly two-thirds of those with a family history of bipolar illness convert from BP-NOS to bipolar I or II. These data provide very strong support for the view that BP-NOS is an early phase of bipolar disorder and should be treated early, as it is highly impairing and difficult to stabilize.
Birmaher also discussed substance abuse among this population of children with bipolar disorder. In 167 bipolar children initially presenting without substance abuse, 32% showed new onset of substance abuse, and in 76% of these individuals, it involved two or more drugs. There was an approximate 6-year lag between onset of bipolar illness at an average age of 12 and onset of substance abuse at average age 18, indicating a substantial therapeutic window for intervention and treatment.
Birmaher presented new data from a latent growth analysis separating youth with bipolar disorder into 4 groups based on the percent of time euthymic during the 90 months (or approximately 8 years) after onset. About 30% showed a course of persistent wellness, while 25% had persistent severe illness. Thirty percent experienced moderate illness throughout the follow-up period. Most interestingly, 15% showed a course of relatively severe illness for the first 30 months and then a relatively rapid progression to consistent wellness thereafter. The reasons for this relatively sudden transition are not yet clear. However, Birmaher speculated that it could be related to changes in brain chemistry and maturity or diverse psychosocial issues such as leaving the home environment or perhaps deciding to avoid alcohol or other substances of abuse. This intriguing group of patients will be studied in more detail in order to ascertain the mechanisms involved in their improvement. This 15% of participants, along with the 30% who were consistently well, indicate that 45% of those with childhood-onset bipolar disorder do very well over long-term followup.
