Children with anhedonia (loss of interest and pleasure in previously enjoyable activities) show differences in brain activity and connectivity during reward anticipation, according to a new study by scientists at the National Institute of Mental Health (NIMH).
Anhedonia is a risk factor for, and symptom of, certain mental disorders and can also be a predictor of illness severity, resistance to treatment, and suicide risk.
While scientists have sought to understand the brain mechanisms behind anhedonia, most research has focused on adults rather than children. And many of these studies did not separate anhedonia from other related psychological conditions, such as low mood, anxiety, or attention-deficit/hyperactivity disorder (ADHD).
The new findings, published in the journal JAMA Psychiatry, shed light on how the brain functions in children with anhedonia and help differentiate anhedonia from other related mental health symptoms.
“Understanding the neural mechanisms of anhedonia that are distinguishable from other psychiatric concerns is important for clinicians to develop on-target treatments,” said lead study author Narun Pornpattananangkul, Ph.D., a postdoctoral fellow in the Emotion and Development Branch, part of NIMH’s Division of Intramural Research Programs.
“Yet, disentangling shared characteristics from unique neural mechanisms of anhedonia is challenging because it often co-occurs with other psychiatric conditions.”
For the study, researchers from the NIMH Division of Intramural Research Programs examined functional magnetic resonance imaging (fMRI) data collected from more than 2,800 children (9-10 years old) as part of the Adolescent Brain Cognitive Development (ABCD) Study.
Some of the children included in the sample were identified as having anhedonia, low mood, anxiety or ADHD. The researchers collected fMRI data while the children were at rest and while they completed tasks assessing reward anticipation and working memory.
The findings show significant differences in children with anhedonia compared to children without the condition. Many of these differences were related to the connectivity between the arousal-related cingulo-opercular network and the reward-related ventral striatum area.
“We found anhedonia-specific alterations, such that youth with anhedonia, but not youth with low mood, anxiety, or ADHD, showed differences in the way they integrated reward and arousal and also showed diminished activity in reward-anticipation contexts,” said Pornpattananangkul.
But this hypoactivation was not seen in children with low mood, anxiety, or ADHD. In fact, kids with ADHD showed the opposite pattern: abnormalities in brain activation during the working memory task, but the not the reward anticipation task.
The findings suggest that children with anhedonia have differences in the way their brain integrates reward and arousal and in the way their brain activates when anticipating rewards.
Pornpattananangkul explained, “This finding may start to provide the specific neural targets for treating anhedonia in youth.”