title: Developmental differences according to age at onset in juvenile bipolar disorder.
abstract: BACKGROUND
  This study on a large sample of unselected, consecutive children and adolescents referred to a third-level hospital who received a diagnosis of bipolar disorder (BD) was aimed at exploring whether childhood-onset BD, as compared with adolescent-onset BD, presents specific clinical features in terms of severity, functional impairment, course, prevalent mood, pattern of co-morbidity, and treatment outcome.
  
  
  METHODS
  A total of 136 patients, 81 males (59.6%) and 55 females (40.4%), mean age 13.5 +/- 2.9 years, meeting the Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV) diagnosis of BD according to a structured clinical interview Schedule for Affective Disorders and Schizophrenia for School-Age Children-Present and Lifetime Version (KSADS-PL), were included in the study.
  
  
  RESULTS
  Eighty patients (58.8%) had a childhood-onset BD (before 12 years of age) and 56 (41.2%) had an adolescents-onset BD. Compared with the adolescent-onset BD, patients with childhood-onset were more frequently males and had a more frequent co-morbidity with attention-deficit/hyperactivity disorder (ADHD) and oppositional defiant disorder (ODD). An episodic course was found in only 42.5% of bipolar children, but 76.8% of youngsters with adolescent-onset BD. Severity, 6-month treatment outcome, prevalent mood (elated versus irritable), and co-morbid anxiety did not differentiate the two groups.
  
  
  CONCLUSIONS
  Our findings suggest that a very early age at onset may identify a form of BD with a more frequent subcontinuous course and a heavy co-morbidity with ADHD.
authors.affiliation: IRCCS Stella Maris, Scientific Institute of Child Neurology and Psychiatry, Calambrone, Pisa, Italy. gabriele.masi@inpe.unipi.it
authors.forename: Gabriele
authors.initials: G
authors.lastname: Masi
authors.forename: Giulio
authors.initials: G
authors.lastname: Perugi
authors.forename: Stefania
authors.initials: S
authors.lastname: Millepiedi
authors.forename: Maria
authors.initials: M
authors.lastname: Mucci
authors.forename: Cristina
authors.initials: C
authors.lastname: Toni
authors.forename: Nicoletta
authors.initials: N
authors.lastname: Bertini
authors.forename: Chiara
authors.initials: C
authors.lastname: Pfanner
authors.forename: Stefano
authors.initials: S
authors.lastname: Berloffa
authors.forename: Cinzia
authors.initials: C
authors.lastname: Pari
mesh_terms: D000293:Adolescent; D000339:Affect; D017668:Age of Onset; D001289:Attention Deficit Disorder with Hyperactivity / Q000150:complications / Q000523:psychology; D019958:Attention Deficit and Disruptive Behavior Disorders / Q000150:complications / Q000523:psychology; D001714:Bipolar Disorder / Q000453:epidemiology / Q000473:pathology* / Q000523:psychology; D002648:Child; D002657:Child Development / Q000502:physiology*; D015897:Comorbidity; D005260:Female; D006801:Humans; D008297:Male; D011569:Psychiatric Status Rating Scales; D012737:Sex Factors; D016896:Treatment Outcome