Difficulty concentrating
Summary
- ADHD groups tend to vary more between fast and slow responses in experimental tasks.
- Difficulties may involve resuming work after interruptions or being more prone to boredom.
ADHD groups have more variable response times in experiments
Research-backed
A meta-analysis of 319 studies found greater variation in response times among people with attention deficit hyperactivity disorder (ADHD) than among typical peers of the same age. Responses were more likely to vary between fast and slow within the same task(Kofler et al., 2013).
An approximate conversion compares one randomly selected person with ADHD and one typical peer of the same age. The chance of greater response variability in the person with ADHD was about 70% for children and adolescents, and 63% for adults(Kofler et al., 2013).
Barkley’s model links resuming work to keeping the plan in mind
Proposed in research
Barkley’s behavioral inhibition model proposes that resuming a task after interruption requires keeping the original plan in mind during the interruption. The model links difficulty with this ability to greater difficulty resuming the task(Barkley, 1997).
This explanation comes from the 1997 model, mainly addressing hyperactive-impulsive and combined types of ADHD. It does not cover the predominantly inattentive type(Barkley, 1997).
In a study, self-relevant content disrupted ADHD children’s attention
Proposed in research
A child study inserted self-relevant content into an attention task. Children with ADHD then had significantly more variable responses; no such change was detected in controls(Merrill et al., 2022).
The same study scheduled free play before and after schoolwork for children with ADHD. Work completion fell significantly; the effect was more consistent than that of watching a movie. The researchers suggested that thinking about future personal activities might explain this(Merrill et al., 2022).
More ADHD symptoms are linked to greater proneness to boredom
Research-backed
A meta-analysis of 18 mostly correlational studies involving over 20,000 people linked more ADHD symptoms to greater proneness to boredom. The correlation coefficient was 0.40, a moderate association(Muris et al., 2026).
The authors proposed that proneness to boredom may affect motivation, emotion regulation, and the ability to act toward goals(Muris et al., 2026).
Evidence
References (4)
- Meta-analysisReaction time variability in ADHD: a meta-analytic review of 319 studiesKofler MJ, Rapport MD, Sarver DE, Raiker JS, Orban SA, Friedman LM, Kolomeyer EG (2013). Clinical Psychology Review
- TheoryBehavioral inhibition, sustained attention, and executive functions: Constructing a unifying theory of ADHDBarkley RA (1997). Psychological Bulletin
- Cohort studyMind-Wandering and Childhood ADHD: Experimental Manipulations across Laboratory and Naturalistic SettingsMerrill BM, Raiker JS, Mattfeld AT, Macphee FL, Ramos MC, Zhao X, Altszuler AR, Schooler JW, Coxe S, Gnagy EM, Greiner AR, Coles EK, Pelham WE Jr (2022). Research on Child and Adolescent Psychopathology
- Meta-analysisThe Boredom-ADHD Nexus: A Narrative and Meta-Analytic Review of the EvidenceMuris P, Otgaar H, Donkers F (2026). Clinical Child and Family Psychology Review