Fibroblast growth factor 17 (FGF17) is implicated in neurodevelopment and synaptic function, yet its role in motivation remains unclear. This study compared serum FGF17 levels (measured using ELISA) between 74 patients with major depressive disorder (MDD) and 72 healthy controls (HCs), and examined its relationship with negative symptoms measured by the Motivation and Pleasure (MAP) and Expression (EXP) subscales of the Clinical Assessment Interview for Negative Symptoms (CAINS). Compared to HCs, patients with MDD exhibited lower FGF17 levels. Within the MDD group, serum FGF17 showed small to modest negative correlations with the ratings of the MAP and EXP scores. Moreover, multiple linear regression showed that FGF17 was a potential predictor of these scores after FDR correction. These preliminary findings suggest that reduced peripheral FGF17 levels are associated with motivational deficits in patients with MDD, warranting further investigation into its role in the neurobiology of "negative-like" symptoms in this clinical group.

Keywords: FGF17; Major depressive disorder; Motivational deficits; Negative symptoms.