Sex Differences in Internalizing Symptoms and Amygdala Functional Connectivity in Neurotypical Youth

Area of Science:

• Neuroscience
• Developmental Psychology
• Psychiatry

Background:

• Internalizing disorders affect adolescents, but the link between amygdala resting-state functional connectivity (rsFC) and subclinical symptoms in neurotypical youth is not well understood.
• Sex differences in internalizing disorder prevalence suggest potential sex-specific neural mechanisms.

Purpose of the Study:

• To investigate how amygdala rsFC varies across a spectrum of internalizing symptoms in typically developing youth.
• To explore sex differences in the relationship between amygdala rsFC and internalizing symptom severity.

Main Methods:

• Functional magnetic resonance imaging (fMRI) was used to assess amygdala rsFC in 110 typically developing youths (ages 8-17).
• Internalizing symptoms, including anxious-depressed, withdrawn-depressed, and somatic complaints, were measured.
• Connectivity patterns were compared between males and females in relation to symptom severity.

Main Results:

• Females with higher internalizing, anxious-depressed, and somatic symptoms showed greater amygdala connectivity with the cingulate gyrus, insula, and somatosensory cortices compared to males.
• Males with higher anxious-depressed symptoms exhibited weaker amygdala connectivity with the subcallosal prefrontal cortex.
• Sex differences in amygdala rsFC were observed for the whole amygdala and its centromedial and superficial subnuclei.

Conclusions:

• In females, heightened internalizing symptoms correlate with increased amygdala rsFC to regions involved in emotional and sensory processing, suggesting potential implications for emotional regulation.
• These findings highlight sex-specific neural correlates of internalizing symptoms in youth.
• Longitudinal studies are necessary to determine if this hyperconnectivity represents a risk or resilience factor for developing internalizing disorders.