Addiction and psychiatric disorders share structural anomalies

Structural abnormalities that are similar, and sometimes even superior, to those seen in the brains of people with certain psychiatric disorders are found in the brain of people suffering from addiction, reveals a study by CHU Sainte-Justine researchers. .

By comparing alcohol and cannabis dependent patients to non-dependent subjects of the same age and sex, Professor Patricia Conrod and master’s student Xavier Navarri observed a reduction in brain volumes in regions characteristic of patients with disorders such as schizophrenia, bipolar disorder, major depressive disorder and attention deficit hyperactivity disorder.

These results are consistent with previous studies of structural abnormalities associated with alcohol and cannabis use in adults.

“We have noticed several effects in the brain in the regions […] which are involved in functions which are very fundamental to the functioning of the brain, to the regulation of stress, to the regulation of emotions, to the ability to respond to the reward , but also in the regions of the brain involved in planning, executive functioning, cognitive control and the ability to regulate behavior in response to emotions, “said Professor Conrod, Department of Psychiatry and Addictology Montreal university.

However, the study does not determine whether the consumption of alcohol or cannabis is responsible for these structural abnormalities, or whether the presence of these abnormalities makes them more vulnerable to addiction.

“This study is unable to differentiate between [the egg and the chicken],” said Ms. Conrod. It is clear that we need more studies […] to be able to distinguish between neurocognitive problems that are causally related to consumption, or that can be affected by consumption. […] It’s probably a combination of both. ”

Cortical thickness

Study compares data from 435 participants with alcohol use disorders to a control group of 363 people, and 200 participants reporting heavy cannabis use or cannabis use disorder to a control group of 247 people non-consuming.

A meta-analysis was performed to observe common brain abnormalities in alcohol and cannabis dependent patients.

The authors warn that the findings of studies that compare heavy users of cannabis to non-users show strong heterogeneity, suggesting significant individual variations between the misuse of cannabis and the structure of the brain.

“It may be related to the fact that at the moment it is difficult to determine an addiction to cannabis, because the consumers are rather regular users; the profile is a little different from alcohol, “said Professor Conrod.

Researchers have found a reduction in cortical thickness in people who are addicted to alcohol and cannabis, as well as those with major depressive disorder. The reduction in alcoholic patients has also been observed in patients with schizophrenia or bipolar disorder.

The reduction in brain volumes in some areas was comparable for cannabis use disorders, alcoholism and other psychiatric conditions.

The results of this study, adds Ms. Conrod, demonstrate that people who are struggling with addiction need help that goes beyond simply ending their use.

“There is certainly a need in people who suffer from alcohol dependence or abuse for neurocognitive rehabilitation services, and not only a service that helps them to stop drinking,” she said. said.

“There are certainly some neuropsychological interventions that can help people get back to functioning or at least get back a little faster and easier.” These types of services are not yet offered in a systematic and equal manner. ”

The study was published online by the medical journal Human Brain Mapping.