Neuropeptide Y in PTSD, MDD, and chronic stress: A systematic review and meta‐analysis

Abstract

Previous studies have suggested that neuropeptide Y (NPY) levels may be altered in patients with major depressive disorder (MDD), post‐traumatic stress disorder (PTSD) and chronic stress. We investigated, through systematic review and meta‐analysis, whether the mean levels of NPY are significantly different in patients with MDD, PTSD or chronic stress, compared to controls. The main outcome was the pooled standardized mean difference (SMD) with 95% confidence intervals between cases and controls, using the random‐effects model. Heterogeneity and publication bias were evaluated. Thirty‐five studies met eligibility criteria. Meta‐regression determined that medication and sex could explain 27% of the between‐study variance. Females and participants currently prescribed psychotropic medications had significantly higher levels of NPY. NPY levels were significantly lower in plasma and cerebrospinal fluid (CSF) in PTSD patients versus controls. Patients with MDD had significantly lower levels of NPY in plasma compared to controls, but not in the CSF. The magnitudes of the decrease in plasma NPY levels were not significantly different between PTSD and MDD. However, chronic stress patients had significantly higher plasma NPY levels compared to controls, PTSD or MDD. Our findings may imply a shared role of NPY in trauma and depression: nevertheless, it is not clear that the association is specific to these disorders. Psychotropic medications may help restore NPY levels. Further controlled studies are needed to better delineate the contribution of confounding variables such as type of depression, body mass index, appetite or sleep architecture.

Neuropeptide Y and Peptide YY in Association with Depressive Symptoms and Eating Behaviours in Adolescents across the Weight Spectrum: From Anorexia Nervosa to Obesity

“…The NPY receptors in the hippocampus, cerebral cortex, and amygdala are essential for NPY regulation of anxiety, reactivity to stress, cognitive processes, and depression [ 102 ]. Animal studies have suggested that lower NPY levels are associated with posttraumatic stress disorder (PTSD), depression, and anxiety-like symptoms [ 37 ], and intracerebral NPY administration reduces anxiety and improves mood [ 30 , 103 ]. A meta-analysis of the studies conducted among patients with major depressive disorder (MDD) confirmed that NPY levels are decreased in this disease [ 104 ].…”

Neuropeptide Y Is an Immunomodulatory Factor: Direct and Indirect

“…The level of plasma NPY is significantly increased in patients with depression ( 139 ), and the NPY gene can be used as a risk gene for severe depression ( 140 ). However, NPY expression in the brain decreases overall during depression ( 13 ).…”

Sex Differences in the Neuropeptide Y System and Implications for Stress Related Disorders

“…The involvement of NPY in attenuating effects of stress, which has been studied primarily in males, has been the topic of a number of excellent, recent reviews [ 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 ]. However much less is known about NPY’s stress-responsive role in females.…”