News > Obsessive-Compulsive Disorder (OCD): A Problem with “Air Traffic Control”?

Obsessive-Compulsive Disorder (OCD): A Problem with “Air Traffic Control”?

July 6, 2022

Dr. Paul Arnold, MD, PhD, FRCPC, Director, The Mathison Centre for Mental Health Research & Education, Alberta Innovates Translational Health Chair in Child and Youth Mental Health, Professor, Departments of Psychiatry and Medical Genetics, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary

 

Obsessive-compulsive disorder (OCD) is a common and impairing mental health condition that affects between 1-2% of the general population. OCD involves obsessions (recurring and unwanted thoughts) and compulsions (repetitive behaviors). OCD is known to be highly heritable, based on family and twin studies, and finding genes that confer risk for OCD is an area of active investigation.1 Environmental influences also play a major role in OCD,2 exerting their effects on brain architecture at sensitive periods in development, most likely in late childhood or adolescence when OCD typically begins. The altered brain architecture in OCD involves structural and functional abnormalities in “fronto-striato-thalamic circuits”,3 and is reflected in altered executive functioning,4 or “air traffic control”.

Executive functions are higher-level neurocognitive processes involved in regulating and guiding behavior in an ever-changing environment.5 One executive function process thought to be particularly relevant to OCD is response inhibition, the ability to stop an action or thought when one’s goals and external circumstances change.4 This difficulty stopping may explain the difficulty individuals with OCD have in terminating repetitive behaviors (compulsions).

Excellent everyday examples of response inhibition are the ability to press the brakes when traffic lights change, or to “check” a swing in baseball. Our group has recently published two studies of a highly validated computerized test of response inhibition, the Stop Signal Task (SST).6-7 During the SST, the participant is presented with a “go” stimulus on a computer screen (e.g., X or O) and is instructed to perform a motor response (e.g., press a button). At random intervals, this “go” signal is followed by a stop signal (e.g., an auditory tone) at which time the participant is supposed to “check” their response (again, think of brakes or checked swing of a bat). Individuals with poor response inhibition have more difficulty stopping and therefore perform poorly on this task.

In the first study, the largest neurocognitive study of children (age 7-17) with OCD to date, we identified impaired response inhibition in comparison to typically developing peers. Interestingly, child participants in this study with elevated OCD symptoms measured using questionnaires had poor response inhibition even if they were never diagnosed with OCD.7 This suggests that poor air traffic control may be an indicator of OCD, a syndrome known to be under-recognized and under-diagnosed.

In the second study, we broadened our scope with a systematic review and meta-analysis on all published studies of the SST in OCD. Our meta-analysis found that individuals with OCD have poorer response inhibition compared with people without OCD, and furthermore that older individuals with OCD have worse response inhibition compared with younger ones.6

Taken together, these studies suggest that poor air traffic control, specifically poor response inhibition, is a feature of OCD. Furthermore, response inhibition may be an important target for early intervention, given the evidence that the deficit in response inhibition in OCD appears to become more pronounced with age. Interestingly, there is some evidence that children with poor air traffic control (based on a range of measures including the SST) may be better responders to conventional treatment for OCD (cognitive-behavioral therapy or CBT) than children with intact executive functioning. Future research may be warranted to determine if treatments directly targeting the brain architecture underlying executive function, such as transcranial magnetic stimulation,8 may be helpful for OCD.

References:

  1. Mahjani, B., Bey, K., Boberg, J., & Burton, C. (2021). Genetics of obsessive-compulsive disorder. Psychological Medicine, 51, 2247-2259.
  2. Brander, G., Pérez-Vigil, A., Larsson, H., & Mataix-Cols, D. (2016). Systematic review of environmental risk factors for obsessive-compulsive disorder: A proposed roadmap from association to causation. Neuroscience & Biobehavioral Reviews, 65, 36-62. 
  3. Colzato, L. S., Hommel, B., Zhang, W., Roessner, V., & Beste, C. (2022). The metacontrol hypothesis as diagnostic framework of OCD and ADHD: A dimensional approach based on shared neurobiological vulnerability. Neuroscience & Biobehavioral Reviews, 137, 104677. 
  4. Robbins, T. W., Vaghi, M. M., & Banca, P. (2019). Obsessive-compulsive disorder: Puzzles and prospects. Neuron, 102, 27-47. 
  5. Hosenbocus, S., & Chahal, R. (2012). A review of executive function deficits and pharmacological management in children and adolescents. Journal of the Canadian Academy of Child and Adolescent Psychiatry, 21, 223–229. 
  6. Mar, K., Townes, P., Pechlivanoglou, P., Arnold, P. D., & Schachar R. (2022). Obsessive compulsive disorder and response inhibition: Meta-analysis of the stop-signal task. Journal of Psychopathology and Clinical Science, 131, 152 – 161.
  7. Schachar, R. J., Dupuis, A., Anagnostou, E., Georgiades, S., Soreni, N., Arnold, P. D., Burton, C.L., & Crosbie, J. (in press). Obsessive-compulsive disorder in children and youth: Neurocognitive function in clinic and community samples. Journal of Child Psychology and Psychiatry. 
  8. Ameis, S. H., Blumberger, D. M., Croarkin, P. E., Mabbott, D. J., Lai, M. C., Desarkar, P., Szatmari, P., & Daskalakis, Z. J. (2020). Treatment of executive function deficits in autism spectrum disorder with repetitive transcranial magnetic stimulation: A double-blind, sham-controlled, pilot trial. Brain Stimulation, 13, 539-547.