Understand Neurobiology Obsessive-Compulsive Disorder
What The Research Tells us About Obsessive Compulsive Disorder
Studies of neurophysiological disorders, like OCD and other neuro-based disorders have focused on specific brain regions, primarily on the orbitofrontal cortex (OFC) and basal ganglia, in its pathophysiology. Furthermore, recent neurobiological studies of OCD have found a close correlation between clinical symptoms, cognitive function, and brain function. Researches have observed patterns of high activities in the OFC in individuals with OCD.
Attention & OCD
The concept of attention consists of three elements: information processing, attention span, and selective attention. Many researchers have tested for deficits in information processing and attention span using cognitive tests. Although studies have demonstrated decreased information processing speed, there is little evidence for a marked impairment of these functions in OCD. On the other hand, in terms of selective attention, some researchers hypothesize that patients with OCD have difficulty switching attention. Additionally, results from an fMRI study was conducted focusing on task-switching and and found that patients with OCD had significantly higher error rates in trials and reduced activation in prefrontal regions of the brain. Thus, neuro-imaging studies may provide evidence of attention-processing disturbances in OCD.
Executive Function & OCD
Executive function is the higher cognitive function that controls and manages other cognitive processes. This includes planning, cognitive flexibility, rule-taking, changing sets, and problem-solving abilities. Because the concept of executive function may be plausible in explaining the persistent and inflexible thinking and behavior of OCD, many researchers have looked at executive function in OCD. Similarly, The Wisconsin Card Sorting Test (WCST) is suitable for testing overall variability. From this research, it was observed that individuals with OCD scored lower that those without OCD.
   However, there is research that suggests that this is a result of a lack of cognitive flexibility. An fMRI study showed significantly stronger left prefrontal cortex activation in patients with OCD compared with normal controls when running the word generation test. Therefore, it seems that executive impairment may be a likely explanation for behaviors such as inadequate decision making or lack of flexibility in changing behavior commonly seen in OCD.Â
Working Memory & OCD
Working memory is one of the higher cognitive functions involved in mediating integration, processing, removal, and retrieval of information. It differs from the general memory function in that it includes active monitoring and information manipulation. In this regard, some researchers have found impaired working memory in OCD using the Tower of London test. An fMRI study showed that patients with OCD performed poorly at the highest levels of difficulty and engaged in the same pool of brain regions as matched healthy control regions in the midbrain, prefrontal cortex regions and peaks, particularly related to working memory
While there is certainly a specific biological basis for OCD, such as the OCD loop, the complex involvement of different neural networks may underlie its clinical diversity and lead to deviations in responses to treatment. At present, we can derive a certain amount of information from neurobiological studies, but there are many questions that need to be clarified.Â
Getting the Right Help for OCD
There are current treatment options available for OCD and we are confident that the services at Mind by Design can help you on your journey to OCD recovery. With various options for interventions and modalities, your treatment plan will be tailored to your unique needs. Read about our OCD treatment here:
Rebecca is a certified clinical anxiety treatment specialist and provides treatment for OCD, Phobias and Panic Disorder using Exposure Therapy, Virtual Reality Therapy and Mindful-Based CBT. Learn more by clicking on her photo!
References:
- Martinot JL, Allilaire JF, Mazoyer BM et al. Obsessive-compulsive disorder: A clinical, neuropsychological and positron emission tomography study. Acta Psychiatr. Scand. 1990; 82: 233–242.
- Schmidtke K, Schorb A, Winkelmann G, Hohagen F. Cognitive frontal lobe dysfunction in obsessive-compulsive disorder. Biol. Psychiatry 1998; 43: 666–673.
- Nakao T, Nakagawa A, Yoshiura T et al. A functional MRI comparison of patients with obsessive-compulsive disorder and normal controls during a Chinese character Stroop task. Psychiatry Res. 2005; 139: 101–114.
- Gu BM, Park JY, Kang DH et al. Neural correlates of cognitive inflexibility during task-switching in obsessive-compulsive disorder. Brain 2008; 131: 155–164.
- Head D, Bolton D, Hymas N. Deficit in cognitive shifting ability in patients with obsessive-compulsive disorder. Biol. Psychiatry 1989; 25: 929–937.
- Abbruzzese M, Ferri S, Scarone S. Wisconsin Card Sorting Test performance in obsessive-compulsive disorder: No evidence for involvement of dorsolateral prefrontal cortex. Psychiatry Res. 1995; 58: 37–43.
- Gross-Isseroff R, Sasson Y, Voet H et al. Alternation learning in obsessive-compulsive disorder. Biol. Psychiatry 1996; 39: 733–738.
- Lucey JV, Burness CE, Costa DC et al. Wisconsin Card Sorting Task (WCST): Errors and cerebral blood flow in obsessive-compulsive disorder (OCD). Br. J. Med. Psychol. 1997; 70: 403–411.
- Cavedini P, Ferri S, Scarone S, Bellodi L. Frontal lobe dysfunction in obsessive-compulsive disorder and major depression: A clinical-neuropsychological study. Psychiatry Res. 1998; 78: 21–28.
- Pujol J, Torres L, Deus J et al. Functional magnetic resonance imaging study of frontal lobe activation during word generation in obsessive-compulsive disorder. Biol. Psychiatry 1999; 45: 891–897.
- Purcell R, Maruff P, Kyrios M, Pantelis C. Neuropsychological deficits in obsessive-compulsive disorder: A comparison with unipolar depression, panic disorder, and normal controls. Arch. Gen. Psychiatry 1998; 55: 415–423.
- Mataix-Cols D, Junqué C, Sà nchez-Turet M et al. Neuropsychological functioning in a subclinical obsessive-compulsive sample. Biol. Psychiatry 1999; 45: 898–904.
- van der Wee NJ, Ramsey NF, Jansma JM et al. Spatial working memory deficits in obsessive compulsive disorder are associated with excessive engagement of the medial frontal cortex. Neuroimage 2003; 20: 2271–2280.
- Nakao T, Nakagawa A, Nakatani E et al. Working memory dysfunction in obsessive-compulsive disorder: A neuropsychological and functional MRI study. J. Psychiatr. Res. 2009; 43: 784–791.
- Kang DH, Kwon JS, Kim JJ et al. Brain glucose metabolic changes associated with neuropsychological improvements after 4 months of treatment in patients with obsessive-compulsive disorder. Acta Psychiatr. Scand. 2003; 107: 291–297.
- van der Wee NJ, Ramsey NF, van Megen HJ et al. Spatial working memory in obsessive-compulsive disorder improves with clinical response: A functional MRI study. Eur. Neuropsychopharmacol. 2007; 17: 16–23.