Time Reproduction Deficits at Young Adult Follow-Up in Childhood ADHD: The Role of Persistence of Disorder and Executive Functioning

Time Perception in Adult ADHD: Findings from a Decade-A Review

Time perception is impaired in adult ADHD. Since the term time perception subsumes different constructs, including time estimation, time reproduction, time production, and duration discrimination, it remains open whether certain domains are more affected than other domains in adult ADHD. The aim of this explorative review is to present the current state of research on time perception in adult ADHD by analysing studies from the past 10 years. A review of the literature addressing adult ADHD time perception, time estimation, and time reproduction was performed. The search strategy was conducted by using the databases "PubMed", "Medline", and "PSYNDEX". The results of the present review indicate that the number of studies on time perception in adult ADHD is very scarce. Moreover, the main investigated domains of time perception in the past decade were time estimation, time reproduction and time management. Whereas some of the found studies were able to demonstrate a distinct deficit in time estimation, time reproduction and time management other studies were unable to demonstrate a clear association between ADHD and time estimation and time reproduction deficits. However, the diagnostic protocols, study design, and methodology varied between studies. Further studies on time estimation and time reproduction need to be carried out.

Meta-analysis: Altered Perceptual Timing Abilities in Attention-Deficit/Hyperactivity Disorder

OBJECTIVE

We meta-analyzed studies comparing perceptual timing abilities in the range of milliseconds to several seconds in persons with attention-deficit/hyperactivity disorder (ADHD) and neurotypical participants, using the well-established time discrimination, time estimation, time production, and time reproduction paradigms.

METHOD

We searched PubMed, OVID databases, and Web of Knowledge through September 17, 2020. From 2,266 records, 55 studies were retained and meta-analyzed with random effects models. We conducted meta-regression analyses to explore moderating effects of task parameters and neuropsychological measures of working memory, attention, and inhibition on timing performance.

RESULTS

Compared with persons without ADHD, those with ADHD had significantly more severe difficulties in discriminating stimuli of very brief durations, especially in the sub-second range. They also had more variability in estimating the duration of stimuli lasting several seconds. Moreover, they showed deficits in time estimation and time production accuracy, indicative of an accelerated internal clock. Additional deficits in persons with ADHD were also found in the time reproduction paradigm, involving attentional (slower counting at short time intervals due to distraction) and motivational (faster counting at long time intervals due to increased delay aversion) functions.

CONCLUSION

There is meta-analytic evidence of a broad range of timing deficits in persons with ADHD. Results have implications for advancing our knowledge in the field (eg, for refinement of recent timing models in ADHD) and clinical practice (eg, testing timing functions to characterize the clinical phenotype of the patient and implementation of interventions to improve timing abilities).

Impaired auditory and visual time reproduction in adult patients with attention deficit-hyperactivity disorder

Objective: Although impaired time perception is associated with significant disturbance in the everyday functioning of adult patients with Attention Deficit-Hyperactivity Disorder (ADHD), it is not very well studied. The present study aimed to evaluate both visual and auditory time reproduction (TR) by using eight time intervals in adult ADHD patients compared to healthy controls (HC).Method: Wechsler Adult Intelligence Scale-R (WAIS-R), Adult Attention Deficit-Hyperactivity Disorder Self-Report Scale (ASRS), Wender Utah Rating Scale (WURS), Hyperfocusing Scale (HS), Beck Depression Inventory (BDI) and a 2-back task were administered to participants. In TR tasks, participants reproduced the same duration of the auditory/visual stimulus by pressing a key and absolute discrepancy scores (ADS) were calculated. A 2 (Group) x 2 (Task Modality) x 8 (Time Interval: 500, 1000, 2000, 4000, 6000, 8000, 12000 and 16000 msec) mixed-design ANOVA was performed.Results: All clinical scores of ADHD group were higher than HC (p < .001) while WAIS-R and 2-back performances of the groups were similar. Mixed-design ANOVA yielded significant Group and Time Interval main effects as well as a Group X Time Interval effect (both p < .001). ADHD patients had larger ADS than HC and as time intervals increased, error levels increased. Errors for time intervals >8000 msec were more prominent in patients. For both TR tasks, ASRS-hyperactivity/impulsivity scores were the main predictor of ADS in the linear regression analysis, while ASRS-attention deficit and HS scores were excluded.Conclusion: Results of the present study indicate significant TR impairment in adult ADHD regardless of task modality (visual or auditory), depressive symptoms and working memory performances. Longer time intervals in TR tasks differentiated patients better and TR impairment was associated with hyperactivity/impulsivity. These findings should be replicated in larger samples and underlying neurobiological components of impaired TR need to be examined in future research.