ObjectivesThe present study was aimed at evaluating the effects of the administration of β-carboline harmine on behaviour and citrate synthase activity in the brain of rats exposed to chronic mild stress (CMS) procedure.MethodsTo this aim, after 40 days of exposure to CMS procedure, rats were treated with harmine (15 mg/kg/day) for 7 days, then memory, anhedonia and citrate synthase activity were assessed.ResultOur findings demonstrated that stressed rats treated with saline increased the sucrose intake, and the stressed rats treated with harmine reversed this effect. Neither stress nor harmine treatment altered memory performance in rats. In addition, chronic stressful situations induced increase in citrate synthase activity in the prefrontal cortex, but not in the hippocampus and striatum. Treatment with harmine reversed the increase in citrate synthase activity in the prefrontal cortex.ConclusionThese findings support the hypothesis that harmine could be involved in controlling the energy metabolism.