Trauma-related dysfunction in the fronto-striatal reward circuit

Area of Science:

• Neuroscience
• Psychiatry
• Mental Health Research

Background:

• Reduced pleasure response is a hallmark of post-traumatic stress disorder (PTSD).
• Trauma exposure exacerbates anxiety and mood disorders, suggesting widespread reward system dysfunction in internalizing disorders.
• The ventromedial prefrontal cortex (vmPFC) and ventral striatum are key brain regions in the reward circuit.

Purpose of the Study:

• To assess functional activity and connectivity within the fronto-striatal reward circuit.
• To examine these neural correlates during emotional picture viewing in patients with anxiety and mood disorders.
• To investigate the influence of trauma exposure and temperament on reward system function.

Main Methods:

• Functional magnetic resonance imaging (fMRI) was used to measure brain activity and connectivity.
• A large sample (n=155) of patients diagnosed with anxiety and mood disorders participated.
• Participants viewed affective scenes, and data were analyzed in relation to trauma exposure and temperament.

Main Results:

• In women, blunted fronto-striatal connectivity correlated with increased post-traumatic anhedonic symptoms.
• Functional activity amplitude was not directly linked to trauma exposure.
• Reduced fronto-striatal connectivity was associated with lower positive affect in both sexes.
• Temperament and post-traumatic symptoms independently predicted fronto-striatal connectivity.

Conclusions:

• Dysfunctional reward processing, influenced by trauma and temperament, is common across internalizing disorders.
• Assessing the fronto-striatal reward circuit's integrity is valuable for diagnosis and treatment.
• Findings suggest a shared neural basis for reward dysfunction in various internalizing conditions.