Researchers scanned the brains of teenagers with OCD while they performed decision-making tasks and identified specific areas affected by OCD. This research sheds light on the biological basis of OCD, which could be used to provide more targeted and effective treatments. Obsessive-compulsive disorder is considered one of the most debilitating mental illnesses. Obsessive-compulsive disorder is characterized by distressing and unwanted thoughts and fears (obsessions) that trigger time-consuming, repetitive behaviors (compulsions) that often have profound effects on social functioning and quality of life. Obsessive-compulsive disorder usually develops in childhood or adolescence.
Researchers use MRI scans to examine what happens to the brains of teenagers with obsessive-compulsive disorder during decision-making Perkes et al./UNSW Sydney
New research from the University of New South Wales Sydney explores the biological basis of obsessive-compulsive disorder in adolescents, revealing how obsessive-compulsive disorder affects the brain's decision-making and control of behavior.
Iain Perkes, lead author of the study, said: "People with OCD don't have complete control over these repetitive actions, compulsions and compulsions. Otherwise, they would just choose not to do them. So there's good reason to think that in the case of OCD, there's something wrong with these decision-making mechanisms in the brain."
The researchers recruited 20 adolescents with obsessive-compulsive disorder and 21 healthy adolescents and asked them to complete a decision-making task in an MRI scanner in exchange for a small food reward while measuring blood flow in the brain. For example, one activity involved playing a computer game in which they tilted a vending machine in different directions, each corresponding to a different snack.
"Every day we make decisions based on environmental cues - for example, the stop and go signals we see at traffic lights. These cues allow us to predict our surroundings," Perkes said.
Before one of the decision-making tasks, participants were shown a video of insects (such as cockroaches) crawling on food, thereby reducing the "value" of the food. "We wanted to see how changing the value of the reward would change the action choices of healthy adolescents and adolescents with OCD," Perkes said.
Compared with controls, adolescents with OCD had difficulty making choices and controlling their behavior to obtain food rewards, and devaluing the food had little effect on their behavior on the task. "People with OCD experience difficulty using reward signals to guide their choices in an adaptive manner, and these behavioral difficulties are associated with changes in the brain."
MRI scans show different patterns of brain activity in teens with obsessive-compulsive disorder compared with controls. Differences were particularly pronounced in the orbitofrontal cortex (OFC), an area located in the frontal lobes involved in decision-making and behavioral control.
During decision-making tasks, participants with OCD showed hypoactivity in the lateral OFC and hyperactivity in the medial OFC. The researchers also found that hyperactivity was associated with the severity of OCD symptoms, supporting a link between decision-making performance and OCD.
The researchers say their findings provide a deeper understanding of the biological basis of OCD, which may reduce the stigma associated with the disorder.
"As we learn more about the biological realities and underpinnings of mental illnesses like OCD, it helps reduce the stigma. It shifts the conversation from 'buck up and work hard' to 'there are changes in the brain; this is a real health condition,'" Perkes said.
The findings could also lead to better treatments. For example, it could lead to more targeted transcranial magnetic stimulation, a treatment that uses magnetic fields to stimulate nerve cells in the brain.
"We know that one-third of patients with OCD do not respond to first-line treatments, and it is necessary to continue to discover new and better treatment paradigms in the future."
The research was published in the journal Biological Psychiatry Global Open Science.