Acute mania is accompanied by elevated glutamate/glutamine levels within the left dorsolateral prefrontal cortex

Rationale. The dorsolateral prefrontal cortex (DLPFC) participates in the pathophysiology of mania. In particular, left-sided structural and metabolic abnormalities have been described. Objectives. Clinical symptoms may be due to hyperactivity of cortical glutamatergic neurons, resulting in increased excitatory neurotransmitter flux and thus enhanced Glx levels. Methods. Glutamate/glutamine (Glx) levels were assessed by proton magnetic resonance spectroscopy (H-1-MRS) in eight acute manic patients compared with age- and gender-matched controls. Results. Manic patients had significantly elevated Glx levels (t-test; t=-3.1, P=0.008) within the left DLPFC. Conclusions. Our results indicate that the prefrontal cortical glutamatergic system is involved in the pathophysiology of acute mania. This may have implications for the treatment of mania.