Lower Ghrelin in Depression Might Be Connected to the Absence of Psychotic-Like Experiences

Major depressive disorder (MDD) prevalence increases every year, with approximately 30% of patients remaining treatment resistant. Ghrelin, a stomach-derived appetite-stimulating hormone, has been implied in mood disorders, stress response, sleep-cycle regulation, reward behaviour, and neuroplasticity. However, findings in human remain unconclusive with reports of higher, unchanged or lowered ghrelin concentration in patients with MDD. Psychotic-like experiences (PLEs), which are more common in the course of depression, might contribute to reported inconsistences. This study aims to assess serum total ghrelin concentrations in individuals with depressive symptoms and investigate whether the PLEs presence modulates the relationship. A cross-sectional study was conducted among 56 individuals screened for depressive symptoms (with Patient Health Questionnaire-9 (PHQ-9)), and presence of PLEs in past year (with Prodromal Questionnaire-16 (PQ-16)). Serum total ghrelin levels were determined by enzyme-linked immunosorbent assay (ELISA). Relationship between PHQ-9 scores and total ghrelin was analysed using linear regression and analysis of covariates (ANCOVA) when controlled for sex, age and body mass index (BMI). Initially, depressive symptoms predicted lower ghrelin levels (p=0.044), however, the model lost its significance when adjusted to covariates (p=0.100). Pairwise comparisons revealed lower total ghrelin among patients with MDD, but without PLEs when compared to controls (p=0.037). No significant differences were observed within patients with history of PLEs. This study provides preliminary evidence that PLEs modulate ghrelin secretion in patients with MDD symptoms. Further studies with larger samples are needed to clarify ghrelin’s role in MDD pathophysiology.