Long-term course of ADHD symptoms from childhood to early adulthood in a community sample

Abstract

Comparatively little information is available from population-based studies on subgroup trajectories of attention-deficit/hyperactivity disorder (ADHD) core symptoms of inattention and hyperactivity-impulsivity (particularly as defined by DSM-IV and ICD-10). Recent report of a subgroup with high and increasing inattention symptoms across development requires replication. To identify the different trajectory subgroups for inattention, hyperactivity-impulsivity and total symptoms of ADHD in children and adolescents aged 7-19 years. Eleven birth cohorts from 2,593 families with children and adolescents who had parent ratings for the outcome measures of inattention, hyperactivity-impulsivity or total symptoms were considered. Data were analysed using an accelerated longitudinal design and growth mixture modelling was applied to detect subgroups. For all three outcome measures, three trajectories with low (78.3-83.3 %), moderate (13.4-18.8 %) and high (2.8-3.2 %) symptom levels were detected. Course within these subgroups was largely comparable across outcome domains. In general, a decrease in symptoms with age was observed in all severity subgroups, although the developmental course was stable for the high subgroups of inattention and total symptoms. About 3 % of children in a community-based sample follow a course with a high level of ADHD symptoms. In this high trajectory group, hyperactivity-impulsivity symptoms decrease with age from 7 to 19 years, whilst inattention and total symptoms are stable. There was no evidence for an increase in symptoms across childhood/adolescence in any of the severity groups.

Should We Subtype ADHD According to the Context in Which Symptoms Occur? Criterion Validity of Recognising Context-Based ADHD Presentations

“…Five classes is a larger number than those generally identified for either inattention or hyperactivity/impulsivity in previous studies of ADHD developmental trajectories [e.g. 23,44,51,52]. Previous studies have, however, only included symptoms as reported by a single informant in their models and could, therefore, not identify distinctions between individuals with different patterns of expression across school and home contexts.…”

Attention deficit hyperactivity disorder and developmental coordination disorder: Two separate disorders or do they share a common etiology.

“…Previous ADHD studies have reported a general decline in hyperactivity-impulsivity symptoms severity across development [49,50], whilst for inattentive symptoms the findings are inconclusive. A reduction [51], stability [48] and increase in attention [49] have all been reported. There are few longitudinal studies for DCD, with many methodological differences among these.…”

“…The developmental course appears to be variable but stable for both disorders [1,40,48]. ADHD symptomatology and motor impairment may vary both in severity and nature, and for both disorders the manifestation of symptoms may differ according to the age at which the diagnosis is considered.…”

Neurobiology of Adult ADHD: Emerging Evidence for Network Dysfunctions

“…Studies indicate that the hyperactive/ impulsive cluster of symptoms tends to wane with age relative to the more enduring inattentive cluster. 8,9,18,19 It has also been suggested that expression of hyperactivity in adults may become internalized as restlessness or inner tension, which may be misinterpreted as anxiety. 9,12 In addition, hyperactive/ impulsive symptoms may become less apparent due to a changing environment with different behavioral constraints.…”