Does age of onset of impairment impact on neuropsychological and personality features of adult ADHD?

Identifying Early Markers of "Late Onset" Attention Deficit and Hyperactivity/Impulsivity Symptoms

Objective: In recent years, there has been an increased focus on "late onset" ADHD, referring to the onset of symptoms beyond childhood, into adolescence and adulthood. We aimed to identify childhood predictors of ADHD symptom increases over development. Method: We used growth mixture modeling to evaluate predictors of a "late onset" symptom trajectories in a longitudinal cohort study of youth measured at eight points from ages 7 to 15. Results: Individuals with high levels of sensation seeking at age 7 were more likely to show a trajectory of ADHD symptoms characterized by increasing levels from age 7 than persistently low symptom levels. Conclusion: The late versus early onset distinction may align with the distinction between deficits in "bottom-up" versus "top-down" processes previously discussed in relation to ADHD. Results also raise the possibility that later onset symptoms could be predicted based on characteristics in childhood.

Outcomes of ADHD Symptoms in Late Adolescence: Are Developmental Subtypes Important?

Objective: Substantial individual variation exists in the age of onset and course of ADHD symptoms over development. We evaluated whether, within this variation, meaningful developmental subtypes can be defined. Method: Using growth mixture modeling in a community-based sample (N = 1,571), we analyzed ADHD symptom trajectories based on measures taken at ages 7, 8, 9, 10, 11, 13, and 15 years. We evaluated whether those showing developmental trajectories characterized by later onsets versus early onsets differed in terms of mental health and behavioral outcomes in late adolescence (age 17 years). Result: The late onset category was best conceptualized as a milder subtype than early onset. The former was, however, more similar in outcomes to the latter than to the unaffected category, suggesting that later onsets are still associated with impairment. Conclusion: Considering diagnoses for those affected by ADHD symptoms but who do not meet current age of onset criteria may be important for ensuring that they receive appropriate support.

A review of changes to the attention deficit/hyperactivity disorder age of onset criterion using the checklist for modifying disease definitions

BACKGROUND

Widening definitions of health conditions have the potential to affect millions of people and should only occur when there is strong evidence of benefit. In the last version of the Diagnostic and Statistical Manual of Mental Disorders (DSM), the DSM-5 Committee changed the Attention Deficit Hyperactivity Disorder (ADHD) age of onset criterion in two ways: raising the age of symptom onset and removing the requirement for symptoms to cause impairment. Given concerns about ADHD prevalence and treatment rates, we aimed to evaluate the evidence available to support these changes using a recently developed Checklist for Modifying Disease Definitions.

METHODS

We identified and analysed research informing changes to the DSM-IV-TR ADHD age of onset criterion. We compared this evidence to the evidence recommended in the Checklist for Modifying Disease Definitions.

RESULTS

The changes to the DSM-IV-TR age of onset criterion were based on a literature review (publicly available as a 2 page document with online table of included studies), which we appraised as at high risk of bias. Estimates of the change in ADHD prevalence resulting from change to the age of onset criterion were based on a single study that included only a small number of children with ADHD (n = 68) and only assessed the impact of change to the age component of the criterion. No evidence was used by, or available to the Committee regarding the impact on prevalence of removal of the requirement for impairment, or the effect of the criterion changes on diagnostic precision, the prognosis of, or the potential benefits or harms for individuals diagnosed by the new, but not old criterion.

CONCLUSIONS

The changes to the age of onset criterion were based on minimal research evidence that suffered from either high risk of bias or poor applicability. The minimal documentation available makes it difficult to judge the rigor of the process behind the criterion changes. Use of the Checklist for Modifying Disease Definitions would assist future proposed modifications of the DSM ADHD criteria, provide guidance on the studies needed to inform potential changes and would improve the transparency and documentation of the process.

Annual Research Review: Does late-onset attention-deficit/hyperactivity disorder exist?

Attention-deficit/hyperactivity disorder (ADHD) is conceptualized as an early onset childhood neurodevelopmental disorder. Prevalence in adults is around two-thirds that in childhood, yet longitudinal outcome studies of children with ADHD found a minority continue to meet full criteria in adulthood. This suggests that not all adult cases meet ADHD criteria as children, a conclusion supported by earlier studies relying on retrospective recall in adolescent and adult samples. More recently prospective follow-up of population and control samples suggest that adolescent and young adult ADHD is not always a continuation of childhood ADHD. Here, we review the literature on age of onset, to explore whether late-onset ADHD exists, and if so, examine the evidence for whether this should be considered the same or a different disorder as childhood onset ADHD. We conclude that current evidence supports the view that a significant proportion of young adults meeting criteria for ADHD would not have met full diagnostic criteria for ADHD as children. However, many in the late-onset group show some ADHD symptoms in childhood, or an externalizing disorder such as oppositional defiant disorder. Furthermore, the current studies suggest that most (but not all) cases of late-onset ADHD develop the disorder between the ages of 12-16 and can therefore be considered adolescent or early adult onset ADHD. There is a relative lack of data spanning young to older adulthood to address the question of adult-onset. Currently, there is insufficient data to clarify the extent to which early and late onset ADHD reflect a different balance of genetic and environmental risks or share the same underlying neural mechanisms. Clinicians should be aware that significantly impairing forms of ADHD can emerge beyond the age of 12 years, although perhaps rarely in the context of a complete absence of precursors. The current evidence on treatment responses is limited.

Replicated association of Synaptotagmin (SYT1) with ADHD and its broader influence in externalizing behaviors

Attention-Deficit/Hyperactivity Disorder (ADHD) is a common psychiatric disorder, affecting both children and adults. The Soluble N-ethylmaleimide sensitive factor Attachment REceptors (SNARE) complex has been implicated in ADHD pathophysiology since it is a key component of neurotransmitter release events and neurodevelopment processes, and SNPs in this complex have been associated with ADHD. Here we aim to analyze the effects of SNARE complex variants on ADHD susceptibility and its clinical heterogeneity in affected adults. We tested the association between ADHD and polymorphisms on the SNARE genes STX1A (rs2228607), SYT1 (rs1880867 and rs2251214), VAMP2 (26bp Ins/Del) and SNAP25 (rs6108461 and rs8636) on a sample comprised of 548 adults with ADHD and 644 non-affected controls. Regarding clinical heterogeneity, we further investigated the effects of associated SNPs on age at onset of impairment due to ADHD and on relevant externalizing behaviors (i.e. school suspensions/expulsions and problems with law/authority) and comorbidities (i.e. Substance Use Disorder, Oppositional Defiant Disorder, Conduct Disorder and Antisocial Personality Disorder). We replicated a previously reported association between SYT1-rs2251214 and ADHD in adulthood. This SNP was also associated with age at onset of impairment due to ADHD symptoms and with a range of externalizing phenotypes. These findings involving SYT1 suggest that variation in neurotransmitter exocytosis mechanisms may represent an underlying genetic factor shared by a spectrum of externalizing behaviors and disorders, including - but not restricted to - ADHD.

Temperament and characteristics related to attention deficit/hyperactivity disorder symptoms

OBJECTIVE

Adult attention deficit/hyperactivity disorder (ADHD) exhibits symptoms, such as attention deficit and impulsivity, that make it difficult for patients to manage social activities. In this study, we investigated the association of adult ADHD symptoms with temperament and character dimensions, taking into account possible sex interactions.

METHOD

A total of 2917 (1462 males and 1455 females) college students completed the 140 5-point Likert items on the Temperament and Character Inventory-Revised Short version (TCI-RS) and the Attention Deficit/Hyperactivity Disorder Self-Rated Scale (ASRS). According to the ASRS score, subjects were classified into the control group, the inattentive ADHD symptom (IA) group, or the hyperactive/impulsive ADHD symptom (HI) group. Additionally, the scores of the four temperament dimensions and the three character dimensions were compared.

RESULTS

In the IA and HI groups, the NS and HA levels of the temperament dimension were high and the PS level was low compared with the control group. In the character dimension, the levels of SD and CO were significantly lower in the ADHD groups than in the control group (P<0.001). Meanwhile, the ST level in the HI group was significantly higher than in the control group. In the regression analysis after age and gender correction, NS and SD in the IA group and NS, CO, and ST in the HI group were associated with adult ADHD symptoms.

CONCLUSION

The current findings suggest that high novelty seeking may be related to adult ADHD symptoms in the temperament dimension. Furthermore, some character dimensions were associated with adult ADHD symptoms.

Personality profiles in adults with attention deficit hyperactivity disorder (ADHD)

BACKGROUND

Previous studies suggested that the presence of ADHD in children and young adolescents may affect the development of personality. Whether or not the persistence of ADHD in adult life is associated with distinct personality patterns is still matter for debate. To address this issue, we compared the profiles of the Temperament and Character Inventory (TCI) that assesses personality dimensions in 119 adults ADHD and 403 controls.

METHODS

ANCOVA were used to examine group differences (controls vs. ADHD and ADHD inattentive type vs. ADHD combined + hyperactive/impulsive types) in Temperaments and Characters. Partial correlation coefficients were used to assess correlation between TCI and expression and severity of symptoms of ADHD.

RESULTS

High novelty seeking (NS), harm avoidance (HA) and self-transcendence (ST) scores as well as low self-directedness (SD) and cooperativeness (C) scores were associated with ADHD diagnosis. Low SD was the strongest personality trait associated with adult ADHD. Cases with the ADHD inattentive type showed higher HA and lower SD scores compared to the combined and hyperactive/impulsive types. High HA scores correlated with inattention symptoms whereas high NS and ST scores were related to hyperactive symptoms. Finally low SD and high NS were associated with increased ADHD severity.

CONCLUSIONS

Distinct temperaments were associated with inattentive versus hyperactive/impulsive symptoms supporting the heterogeneous nature of the disorder.

Rethinking ADHD and LD in DSM-5: proposed changes in diagnostic criteria

The Diagnostic and Statistical Manual of Mental Disorders (DSM) is currently undergoing revision that will lead to a fifth edition (DSM-5) in 2013. This article first provides a brief synopsis of the DSM-5 administrative structure, procedures, and guiding principles to enhance understanding of how changes are made in the DSM. The next two sections (on attention-deficit/hyperactivity disorder and learning disorders, respectively) highlight the major concerns and controversies surrounding the DSM-IV diagnostic criteria for these two disorders and provide a rationale for the proposed changes to the criteria, along with a commentary on the empirical evidence on which the proposed changes were based.