Is it possible to take an fMRI scan of the brain and identify whether a person is likely to develop an addiction? That is the holy grail of addiction diagnostics: to be able to identify the potential to develop mental health disorders from a diagnostic scan.

A team of researchers from the Del Monte Institute for Neuroscience at the University of Rochester in New York have just published the results of a multi-year, longitudinal study indicating that, yes, features spotted in fMRI scans of adolescents performing reward challenges correlate with subsequent gaming addiction problems.

The setup of the study is fascinating. It involves the Adolescent Brain Cognitive Development (ABCD) Study of 11, 878 children aged 9 to 11 who complete the Video Game Addiction Questionnaire (VGAQ). According to the researchers, “Most children were male, White, and had a parent with a college degree. Around 5–6% of children had a present diagnosis of ADHD at each study visit.”

Two years later, children completed the VGAQ again, and also performed a Monetary Incentive Delay task while receiving a functional magnetic resonance imaging (fMRI) scan. Researchers note,

VGAQ scores were greater in males, non-White children, and children from lower income households.

The children then completed VGAQs in years three and four. Due to incompletions or dropouts, the final number of students involved in the statistical analysis was 6,143. The VGAQ scores were subjected to “Bayesian hierarchical modeling” and mapped to the fMRI scans. Out popped this result:

The fully adjusted models found an inverse association between large reward anticipation and VGAQ score in the bilateral caudate. Holding other variables constant, a one-unit increase in the anticipation of a large reward versus neutral condition in the bilateral caudate was associated with a 0.87-point decrease in VGAQ score.

Here is how that “large reward motivation” is measured. While being scanned:

Participants were shown a cue (pink circle, yellow square, or blue triangle) at the beginning of each trial that indicated the trial type (win, loss, no incentive) and amount at stake [$5 or $0.20 or $0]. Participants then had to press a button as soon as the target was shown on screen.

Each trial begins with an “incentive cue” showing the five possible outcomes (win $5, win $0.20, lose $5, lose $0.20, or $0). According to researchers, “The incentive cue represents the anticipation phase.” That is followed by a target and a text message encouraging the participant to respond as quickly as possible to win the money or avoid losing the money. The result is shown instantly before the next trial.

Participants completed the trial 100 times in two, five-minute long sessions. The task is designed to ensure a 60% win rate for monetary trials. Participants earned an average of $21 for their performance. In the end, when all of the analysis and adjustments were completed, researchers stated:

Our results indicate that blunted activity in the caudate nucleus is associated with greater symptoms of gaming addiction over time… Higher activation in the caudate nucleus during the anticipation of a large reward may serve as a protective factor against gaming addiction. The caudate is a fundamental contributor to successful goal-directed action due to its connectivity with higher level cognitive areas, such as the dorsolateral prefrontal cortex.

The researchers then speculate about the inverse relationship between reward anticipation and the tendency toward gaming addiction, and that it may be due to “a blunted reward response and reduced sensitivity to everyday rewards.” Does the blunted reward response play a role in other addictive behaviors? We’ll take a look at that in our next post on AddictionNews.

Written by Steve O’Keefe. First published December 17, 2024.

Sources:

“The longitudinal association between reward processing and symptoms of video game addiction in the Adolescent Brain Cognitive Development Study,” Journal of Behavioral Addictions, December 9, 2024.

“Researchers ‘See’ Vulnerability to Gaming Addiction in the Adolescent Brain,” University of Rochester Medical Center Newsroom, December 9, 2024.

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