INS and type 2 diabetes mellitus: Further evidence for a role of (altered) peripheral insulin signaling in OCD etiology is suggested by the fact that selective serotonin reuptake inhibitors (SSRIs), the first-line pharmacological treatment for OCD, positively affect diabetic parameters when used to treat depressive symptoms in T2D (i.e., decreasing HbA1c levels and insulin requirement, and increasing insulin sensitivity)51.