Cerebrospinal Fluid Neuropeptide Y Levels in Major Depression and Reported Childhood Trauma

BACKGROUND Neuropeptide Y (NPY) may enhance resilience to chronic stress. Low brain NPY reported in major depression may normalize in response to antidepressants. METHODS In this study, we examined the relationship of reported childhood trauma to cerebrospinal fluid (CSF) NPY-like immunoreactivity (NPY-LI) in 61 medication-free major depressive disorder (MDD) patients and 20 matched healthy volunteers. RESULTS Higher CSF NPY-LI was found in MDD compared to the healthy volunteer group (p = 0.01). A positive correlation of CSF NPY-LI with more adverse childhood trauma (p = 0.001) may be indicative of an intact but insufficient NPY-related stress response. CONCLUSIONS We hypothesize that differences in published results may be explained by the existence of two groups of MDD in terms of CSF NPY levels: MDD with low CSF NPY prior to stress or in response to stress, and those with robust NPY responses to stress. Future studies should confirm the two groups and seek the molecular mechanism for their differences.