title: Three-year latent class trajectories of attention-deficit/hyperactivity disorder (ADHD) symptoms in a clinical sample not selected for ADHD.
abstract: OBJECTIVE
  This study aims to examine trajectories of attention-deficit/hyperactivity disorder (ADHD) symptoms in the Longitudinal Assessment of Manic Symptoms (LAMS) sample.
  
  
  METHODS
  The LAMS study assessed 684 children aged 6 to 12 years with the Kiddie-Schedule for Affective Disorders and Schizophrenia (K-SADS) and rating scales semi-annually for 3 years. Although they were selected for elevated manic symptoms, 526 children had baseline ADHD diagnoses. With growth mixture modeling (GMM), we separately analyzed inattentive and hyperactive/impulsive symptoms, covarying baseline age. Multiple standard methods determined optimal fit. The χ(2) and Kruskal-Wallis analysis of variance compared resulting latent classes/trajectories on clinical characteristics and medication.
  
  
  RESULTS
  Three latent class trajectories best described inattentive symptoms, and 4 classes best described hyperactive/impulsive symptoms. Inattentive trajectories maintained their relative position over time. Hyperactive/impulsive symptoms had 2 consistent trajectories (least and most severe). A third trajectory (4.5%) started mild, then escalated; and a fourth (14%) started severe but improved dramatically. The improving trajectory was associated with the highest rate of ADHD and lowest rate of bipolar diagnoses. Three-fourths of the mildest inattention class were also in the mildest hyperactive/impulsive class; 72% of the severest inattentive class were in the severest hyperactive/impulsive class, but the severest inattention class also included 62% of the improving hyperactive-impulsive class.
  
  
  CONCLUSIONS
  An ADHD rather than bipolar diagnosis prognosticates a better course of hyperactive/impulsive, but not inattentive, symptoms. High overlap of relative severity between inattention and hyperactivity/impulsivity confirms the link between these symptom clusters. Hyperactive/impulsive symptoms wane more over time. Group means are insufficient to understand individual ADHD prognosis. A small subgroup deteriorates over time in hyperactivity/impulsivity and needs better treatments than currently provided.
authors: The Ohio State University, Columbus, OH. Electronic address: l.arnold@osumc.edu.
authors: L Eugene
authors: LE
authors: Arnold
authors: Case Western Reserve University, Cleveland.
authors: Stephen J
authors: SJ
authors: Ganocy
authors: The Ohio State University, Columbus, OH.
authors: Katherine
authors: K
authors: Mount
authors: University of North Carolina at Chapel Hill, NC.
authors: Eric A
authors: EA
authors: Youngstrom
authors: Center for Pediatric Behavioral Health and Center for Autism at the Cleveland Clinic, Cleveland.
authors: Thomas
authors: T
authors: Frazier
authors: The Ohio State University, Columbus, OH.
authors: Mary
authors: M
authors: Fristad
authors: New York University Langone Medical Center, New York.
authors: Sarah M
authors: SM
authors: Horwitz
authors: Western Psychiatric Institute and Clinic, University of Pittsburgh Medical Center, Pittsburgh.
authors: Boris
authors: B
authors: Birmaher
authors: Johns Hopkins University and the Kennedy Krieger Institute, Baltimore.
authors: Robert
authors: R
authors: Findling
authors: The Ohio State University and Nationwide Children's Hospital.
authors: Robert A
authors: RA
authors: Kowatch
authors: Case Western Reserve University, Cleveland.
authors: Christine
authors: C
authors: Demeter
authors: The Ohio State University and Nationwide Children's Hospital.
authors: David
authors: D
authors: Axelson
authors: Western Psychiatric Institute and Clinic, University of Pittsburgh Medical Center, Pittsburgh.
authors: Mary Kay
authors: MK
authors: Gill
authors: Case Western Reserve University, Cleveland.
authors: Linda
authors: L
authors: Marsh
mesh_terms: D001289:Attention Deficit Disorder with Hyperactivity / Q000145:classification / Q000175:diagnosis* / Q000453:epidemiology; D001714:Bipolar Disorder / Q000175:diagnosis* / Q000453:epidemiology; D002648:Child; D015897:Comorbidity; D018450:Disease Progression; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D011379:Prognosis; D013997:Time Factors
keywords: ADHD; GMM; hyperactivity/impulsivity; inattention; longitudinal symptoms