Adjunctive L-Carnosine for Depression?

The antioxidant dipeptide L-carnosine has potential neuroprotective and beneficial metabolic effects, and studies have indicated cognitive benefits. L-carnosine upregulates glutamate transporter-1 and reduces extrasynaptic glutamate concentrations; high extrasynaptic glutamate is associated with neuronal malfunctioning and cell death (unlike intrasynaptic glutamate, which is necessary for synaptic plasticity and information processing). In a 6-week, double-blind study, the first-ever of L-carnosine for major depressive disorder (MDD), researchers randomized 58 Iranian patients (men, 56%) with at least moderate MDD to add-on L-carnosine (400 mg twice daily) or placebo.

All patients received citalopram, titrated to 40 mg daily. Exclusion crite…