Depression and the prefrontal-hippocampal pathway - A multimodal neuroimaging study in transgender women

This study aims to investigate functional and neurotransmitter signaling in the prefrontal-hippocampal pathway in relation to depression in a cohort of Thai transgender women. Twenty participants completed mental health surveys and imaging between January and March 2024. Depression severity was measured by Patient Health Questionnaire-9 (PHQ-9) scores. Higher PHQ-9 scores were associated with lower GABA levels in the hippocampus, and with lower fractional amplitude of low-frequency fluctuations (fALFF) in the dorsolateral prefrontal cortex. However, removal of the hippocampal GABA outlier resulted in a non-significant relationship with PHQ-9. Therefore, future studies with larger datasets should further investigate the association between GABA and depression in a transgender cohort. These findings revealed interactions between neurotransmitter signaling and functional brain activity of the hippocampal-prefrontal circuit in depression.