title: Prior stimulant treatment in adolescents with bipolar disorder: association with age at onset.
abstract: OBJECTIVE
  To compare demographic and clinical characteristics between bipolar adolescents with and without a history of stimulant treatment, we hypothesized that adolescents treated with stimulants would have an earlier age at onset of bipolar disorder, independent of co-occurring attention-deficit-hyperactivity disorder (ADHD).
  
  
  METHODS
  Thirty-four adolescents hospitalized with mania were assessed using the Washington University at St Louis Kiddie Schedule for Affective Disorders and Schizophrenia (WASH-U-KSADS). We systematically evaluated age at onset of bipolar disorder and pharmacological treatment history.
  
  
  RESULTS
  Bipolar adolescents with a history of stimulant exposure prior to the onset of bipolar disorder had an earlier age at onset of bipolar disorder than those without prior stimulant exposure. Additionally, bipolar adolescents treated with at least two stimulant medications had a younger age at onset compared with those who were treated with one stimulant. There was no difference in age at onset of bipolar disorder between bipolar adolescents with and without ADHD.
  
  
  CONCLUSIONS
  Our results suggest that stimulant treatment, independent of ADHD, is associated with younger age at onset of bipolar disorder. A behavioral sensitization model is proposed to explain our findings. There are several limitations to our study including the small sample size, the retrospective assessment of stimulant exposure and age at onset of bipolar disorder, and the inclusion of only hospitalized patients, who may be more likely to present with a severe illness. Nonetheless, future prospective longitudinal investigations that systematically assess the effects of stimulant medications in children with or at genetic risk for bipolar disorder are warranted.
authors.affiliation: Bipolar and Psychotic Disorders Research Program, Department of Psychiatry, University of Cincinnati College of Medicine, OH 45267-0559, USA. delbelmp@email.uc.edu
authors.forename: M P
authors.initials: MP
authors.lastname: DelBello
authors.forename: C A
authors.initials: CA
authors.lastname: Soutullo
authors.forename: W
authors.initials: W
authors.lastname: Hendricks
authors.forename: R T
authors.initials: RT
authors.lastname: Niemeier
authors.forename: S L
authors.initials: SL
authors.lastname: McElroy
authors.forename: S M
authors.initials: SM
authors.lastname: Strakowski
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D001289:Attention Deficit Disorder with Hyperactivity / Q000188:drug therapy / Q000453:epidemiology; D001714:Bipolar Disorder / Q000139:chemically induced* / Q000175:diagnosis; D000697:Central Nervous System Stimulants / Q000009:adverse effects*; D015897:Comorbidity; D019955:Conduct Disorder / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D009771:Obsessive-Compulsive Disorder / Q000453:epidemiology; D011569:Psychiatric Status Rating Scales; D013997:Time Factors
chemical_list: D000697:Central Nervous System Stimulants