Trajectories of attention-deficit/hyperactivity disorder dimensions in adults.

OBJECTIVE: There is a lack of available information on the trajectories of attention-deficit/hyperactivity disorder (ADHD) dimensions during adulthood. This study investigates the course and the predictors of change for each ADHD domain in a clinical sample of adults with ADHD. METHOD: Adults with ADHD (n = 344) were followed up for 7 years, with a final retention rate of 66.0%. Trajectories of inattention, hyperactivity, and impulsivity and their potential predictors were examined. RESULTS: On average, symptoms declined in all ADHD domains during follow-up. Despite this, rises in inattentive, hyperactive, and impulsive symptoms were observed in approximately 13%, 25%, and 17% of patients respectively. Different predictors influenced the trajectory of each ADHD dimension. Oppositional defiant disorder and social phobia were associated with the maintenance of symptoms, while alcohol use disorder was associated with both maintenance and rise of symptoms. CONCLUSION: Unexpectedly, a rise in the symptoms after 7 years was not uncommon in adults with ADHD. Prevalent comorbidities have the potential to influence the neurodevelopment and the trajectory of ADHD. Therefore, such predictors should be investigated in population cohorts to better characterize the course of ADHD. Additionally, these findings may be relevant in prevention studies and in strategies for ADHD treatment.

Coordinated brain development: exploring the synchrony between changes in grey and white matter during childhood maturation.

Brain development during childhood and early adolescence is characterized by global changes in brain architecture. Neuroimaging studies have revealed overall decreases in cortical thickness (CT) and increases in fractional anisotropy (FA). Furthermore, previous studies have shown that certain cortical regions display coordinated growth during development. However, there is significant heterogeneity in the timing and speed of these developmental transformations, and it is still unclear whether white and grey matter changes are co-localized. In this multimodal neuroimaging study, we investigated the relationship between grey and white matter developmental changes and asynchronous maturation within brain regions in 249 normally developing children between the ages 7-14. We used structural magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI) to analyze CT and FA, respectively, as well as their covariance across development. Consistent with previous studies, we observed overall cortical thinning with age, which was accompanied by increased FA. We then compared the coordinated development of grey and white matter as indexed by covariance measures. Covariance between grey matter regions and the microstructure of white matter tracts connecting those regions were highly similar, suggesting that coordinated changes in the cortex were mirrored by coordinated changes in their respective tracts. Examining within-brain divergent trajectories, we found significant structural decoupling (decreased covariance) between several brain regions and tracts in the 9- to 11-year-old group, particularly involving the forceps minor and the regions that it connects to. We argue that this decoupling could reflect a developmental pattern within the prefrontal region in 9- and 11-year-old children, possibly related to the significant changes in cognitive control observed at this age.

Persistence and remission of ADHD during adulthood: a 7-year clinical follow-up study.

BACKGROUND: Course and predictors of persistence of attention deficit hyperactivity disorder (ADHD) in adults are still largely unknown. Neurobiological and clinical differences between child and adult ADHD raise the need for follow-up studies of patients diagnosed during adulthood. This study investigates predictors of ADHD persistence and the possibility of full remission 7 years after baseline assessment. METHOD: A 7-year follow-up study of adults with ADHD (n = 344, mean age 34.1 years, 49.9% males) was conducted. Variables from different domains (social demographics, co-morbidities, temperament, medication status, ADHD measures) were explored with the aim of finding potential predictors of ADHD persistence. RESULTS: Retention rate was 66% (n = 227). Approximately a third of the sample (n = 70, 30.2%) did not maintain ADHD criteria and 28 (12.4%) presented full remission (<4 symptoms), independently of changes in co-morbidity or cognitive demand profiles. Baseline predictors of diagnostic persistence were higher number of inattention symptoms [odds ratio (OR) 8.05, 95% confidence interval (CI) 2.54-25.45, p < 0.001], number of hyperactivity/impulsivity symptoms (OR 1.18, 95% CI 1.04-1.34, p = 0.01), oppositional defiant disorder (OR 3.12, 95% CI 1.20-8.11, p = 0.02), and social phobia (OR 3.59, 95% CI 1.12-11.47, p = 0.03). CONCLUSIONS: Despite the stage of brain maturation in adults suggests stability, approximately one third of the sample did not keep full DSM-IV diagnosis at follow-up, regardless if at early, middle or older adulthood. Although full remission is less common than in childhood, it should be considered as a possible outcome among adults.