An investigation of individual typologies of attention-deficit hyperactivity disorder using cluster analysis of DSM-IV criteria

Cluster analysis was used to investigate empirical typologies of inattention and hyperactivity-impulsivity traits and whether these traits would correspond to DSM-IV ADHD typologies. Parents rated 104 male and female children, aged 5 to 14.7 years, on a scale developed to operationalise DSM-IV (American Psychiatric Association, 1994) criteria. Cluster analysis revealed four ADHD typologies with possible developmental changes in hyperactive-impulsive behavior as children mature as well as two 'normal' subgroups. Results indicated that DSM-IV defined ADHD characteristics where present in a cross section of individuals including nonpsychiatric controls. The structure of ADHD characteristics reflected the DSM-IV Combined and Inattentive types but failed to support a robust hyperactivity-impulsivity subgroup. Post hoe analysis suggested this may be a result of developmental factors; wherein hyperactivity-impulsivity traits decrease with age and inattention remains relatively stable. Cluster analysis also suggests that ADHD symptoms are normal personality traits that become pathological at relatively high levels. (C) 2003 Elsevier Ltd. All rights reserved.