Inhibitory control refers to the ability to deliberately stop an impulsive or automatic behavior that is inappropriate in a given situation.
People with attention-deficit/hyperactivity disorder (ADHD) often exhibit problems with inhibitory control, such as interrupting others or failing to think through consequences before acting.
This reflects deficits in the brain’s executive function systems that normally allow for controlled, goal-directed responses rather than impulses.
Understanding links between inhibitory control issues, ADHD symptoms, and factors like motivation and effort can aid early intervention.
Kostyrka‐Allchorne, K., Wass, S. V., Yusuf, H., Rao, V., Bertini, C., & Sonuga‐Barke, E. J. (2023). Inhibitory deficits and symptoms of attention‐deficit hyperactivity disorder: How are they related to effortful control?. British Journal of Developmental Psychology, 41(1), 50-65. https://doi.org/10.1111/bjdp.12432
Key Points
- The study found that effortful control mediated the relationship between ADHD symptoms and inhibitory control deficits. Specifically, reduced effortful control explained why children with more ADHD symptoms had poorer inhibitory control.
- After accounting for conduct problems, the link between ADHD symptoms and inhibitory deficits was fully explained by effortful control. In contrast, conduct problems were directly linked to inhibitory deficits.
- The findings highlight the role of temperamental factors, especially effortful control, in relation to the cognitive-energetic deficits seen in ADHD.
- Understanding the relationships between temperament, cognition, and psychopathology has important implications for the conceptualization, assessment, and management of certain disorders.
Rationale
- Prior research has established links between ADHD symptoms, deficient inhibitory control (a key executive function affected in ADHD), and low effortful control (a temperament factor reflecting ability to regulate attention and behavior) (Krieger et al., 2019).
- However, no study has tested if effortful control mediates the ADHD-inhibitory control link while accounting for conduct problems (co-occurring antisocial, disruptive behaviors such as defiance, aggression, lying and rule-breaking) which often co-occur with ADHD and have also been linked to temperamental factors (Oldehinkel et al., 2004).
- Examining the unique roles of temperament dimensions in relation to cognitive deficits seen in ADHD vs. conduct problems can clarify the nature of regulatory impairments associated with each type of childhood psychopathology.
Method
- 77 children aged 4-7 years and their parents participated.
- Parents completed the Strengths and Difficulties Questionnaire (Goodman, 1997) to measure ADHD symptoms and conduct problems dimensionally.
- The Children’s Behavior Questionnaire (Putnam & Rothbart, 2006) was used to assess child temperament dimensions of effortful control, negative affect, and surgency.
- Children completed the AX-Continuous Performance Task (AX-CPT) to measure inhibitory control, specifically indices of proactive (goal-directed preparation) and reactive (response correction after conflict detected) control.
Sample
- 77 children (30 boys, 47 girls) aged 4 to 7 years (mean 5.5 years)
- Primarily well-educated families (78% had a university degree)
- Ethnically diverse urban UK sample
Statistical Analysis
- Bivariate Pearson correlations
- Partial correlations controlling for conduct problems
- Path analysis with bootstrapping to test for mediation effects
- Model fit assessed using Comparative Fit Index and Root Mean Square Error of Approximation
Results
- As predicted, ADHD symptoms were negatively correlated with both effortful control and inhibitory control. The ADHD-inhibitory control link was no longer significant after controlling for conduct problems.
- Path analysis showed effortful control fully mediated the link between ADHD symptoms and inhibitory deficits when accounting for conduct problems.
- In contrast, conduct problems were directly linked to poorer inhibitory control after accounting for overlap with ADHD symptoms.
Insight
The results suggest that reduced effortful control explains the link between ADHD symptoms and problems with inhibitory control.
Effortful control refers to the capacity to focus attention and inhibit automatic responses. The findings fit with theories that motivation and effort factors affect cognitive control in ADHD.
Unlike ADHD, conduct problems are directly related to poorer inhibition independent of effortful control. This indicates distinct reasons for self-control problems in different childhood disorders.
Overall, the study supports the idea that temperament traits like effortful control underpin the development of cognitive abilities that allow children to regulate thoughts and behavior.
Strengths
- Using questionnaires about symptoms together with a test of inhibitory control ability provides converging evidence using different methods to measure key constructs.
- Looking at normal variation in childhood problems, not just severe cases, shows findings apply across the spectrum of symptom severity, not just impaired extreme groups.
- Accounting for overlap between ADHD and conduct disorders isolates effects specific to each disorder rather than confounded comorbidity.
- Testing the specific role of temperament traits like effortful control clarifies the role of hypothesized developmental factors linking symptoms to cognitive impairment.
- Studying children around the start of formal schooling captures a pivotal period for emerging self-regulation capacities needed to thrive in school.
Limitations
- Small number of participants from a narrow background reduces the statistical power and generalizability of findings.
- Can’t confirm cause-and-effect relationships – cross-sectional data cannot test the directionality of effects.
- Relied on parent reports only to assess child temperament could reflect reporter bias rather than objective child traits.
- Didn’t measure related traits like frustration tolerance, which limits the scope of temperament factors examined as potential mediators.
- Combined different types of inhibitory control into one score, which obscures distinctions between subtypes of inhibition affected.
Implications
- Supports cognitive-energetic models that emphasize motivational and effort factors in ADHD alongside cognitive deficits.
- Highlights the role of temperament assessment in understanding self-regulatory impairments in ADHD.
- Indicates interventions targeting effortful control may address core deficits underlying ADHD symptoms.
- Findings will inform transdiagnostic research examining shared and unique impairment pathways across childhood disorders.
References
Primary reference
Kostyrka‐Allchorne, K., Wass, S. V., Yusuf, H., Rao, V., Bertini, C., & Sonuga‐Barke, E. J. (2023). Inhibitory deficits and symptoms of attention‐deficit hyperactivity disorder: How are they related to effortful control?. British Journal of Developmental Psychology, 41(1), 50-65. https://doi.org/10.1111/bjdp.12432
Other references
Abulizi, X., Pryor, L., Michel, G., Melchior, M., Van Der Waerden, J., & EDEN Mother–Child Cohort Study Group. (2017). Temperament in infancy and behavioral and emotional problems at age 5.5: The EDEN mother-child cohort. PLoS One, 12(2), e0171971.
Goodman, R. (1997). The Strengths and Difficulties Questionnaire: a research note. Journal of child psychology and psychiatry, 38(5), 581-586. https://doi.org/10.1111/j.1469-7610.1997.tb01545.x
Hu, L. T., & Bentler, P. M. (1999). Cutoff criteria for fit indexes in covariance structure analysis: Conventional criteria versus new alternatives. Structural Equation Modeling: A Multidisciplinary Journal, 6(1), 1–55. https://doi.org/10.1080/10705519909540118
Krieger, V., Amador-Campos, J. A., & Gallardo-Pujol, D. (2019). Temperament, executive function, and attention-deficit/hyperactivity disorder (ADHD) in adolescents: The mediating role of effortful control. Journal of Clinical and Experimental Neuropsychology, 41(6), 615–633. https://doi.org/10.1080/13803395.2019.1599824
Oldehinkel, A. J., Hartman, C. A., De Winter, A. F., Veenstra, R., & Ormel, J. (2004). Temperament profiles associated with internalizing and externalizing problems in preadolescence. Development and Psychopathology, 16(2), 421–440. https://doi.org/10.1017/S0954579404044591
Putnam, S. P., & Rothbart, M. K. (2006). Development of short and very short forms of the Children’s behavior questionnaire. Journal of Personality Assessment, 87(1), 102–112.
Keep Learning
Here are potential Socratic seminar questions about this research to stimulate deeper discussion in a college class:
- What theories might explain the mechanisms linking effortful control to inhibitory deficits seen in relation to ADHD symptoms?
- How might proactive vs reactive inhibition develop differently over time? At what ages might we expect to see divergence?
- What interventions could effectively improve effortful control and reduce ADHD symptoms? What outcomes would result?
- How might sex differences affect the symptom presentations and pathways to impairment in ADHD vs conduct disorder?
- What types of longitudinal research designs could establish causal links between temperament, cognition, and childhood psychopathology over development?
