July 14, 2024

MRI Scans Reveal How Obsessive-Compulsive Disorder (OCD) Impacts the Brain’s Decision-Making Mechanisms

New research conducted by the University of New South Wales Sydney has utilized MRI scans to examine the brains of adolescents with obsessive-compulsive disorder (OCD) as they performed decision-making tasks. The results of the study provide a deeper understanding of the biological basis of OCD and could potentially lead to more effective and targeted treatment options.

OCD is characterized by persistent and unwanted thoughts and fears, known as obsessions, which trigger repetitive behaviors, or compulsions. The disorder often has a significant impact on an individual’s social functioning and overall quality of life and typically presents during childhood or adolescence.

The study aimed to investigate how OCD affects the brain’s decision-making processes and behavioral control. Lead author Iain Perkes explains that individuals with OCD do not have complete control over their repetitive actions, obsessions, and compulsions. This suggests that the decision-making mechanisms in the brain may malfunction in individuals with OCD.

The researchers recruited a group of 20 adolescents with OCD and a control group of 21 healthy adolescents. Participants were asked to complete decision-making tasks while inside an MRI scanner, which measured blood flow in the brain. For example, one task involved playing a computer game where participants tilted a vending machine to receive different snacks.

The researchers aimed to understand how altering the value of the food reward would impact decision-making and behavior for both the control group and individuals with OCD. Participants were shown a video of insects crawling over the food, reducing its perceived value.

The study revealed that adolescents with OCD struggled to make decisions and control their behavior to gain food rewards compared to the control group. Additionally, reducing the value of the food had minimal influence on their decision-making during the tasks.

The MRI scans showed distinct patterns of brain activity in individuals with OCD compared to the control group. The differences were particularly noticeable in the orbitofrontal cortex (OFC), a region of the frontal lobe that plays a vital role in decision-making and behavioral control.

During the decision-making tasks, the lateral OFC exhibited hypoactivity in individuals with OCD, while the medial OFC showed hyperactivity. Furthermore, the researchers found that the level of hyperactivity in the medial OFC was linked to the severity of OCD symptoms, further supporting the connection between decision-making and the disorder.

The researchers believe that these findings contribute to a greater understanding of the biological basis of OCD. This increased understanding may help reduce the stigma surrounding the disorder by highlighting that it has a biological basis.

Furthermore, these findings have the potential to pave the way for more effective treatments. For example, the research may lead to the development of more targeted transcranial magnetic stimulation, a treatment that utilizes magnetic fields to stimulate nerve cells in the brain.

Iain Perkes emphasizes that approximately one-third of individuals with OCD do not respond to first-line treatments, highlighting the need for continued research into new and improved treatment approaches. By unraveling the biological reality and mechanisms behind mental health conditions like OCD, the stigma surrounding these disorders can be minimized, shifting the focus from personal willpower to acknowledging the genuine health condition that exists within the brain.


  1. Source: Coherent Market Insights, Public sources, Desk research
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