Allopurinol for mania: a randomized trial of allopurinol versus placebo as add-on treatment to mood stabilizers and/or antipsychotic agents in manic patients with bipolar disorder.

Objective: An emerging body of evidence supports a role for dysfunctional purinergic neurotransmission in mood disorders. Adenosine agonists have been shown to have properties similar to those of dopamine antagonists; there is a well-characterized interaction between adenosine and dopamine receptors in the ventral striatum, and increasing adenosinergic transmission has been demonstrated to reduce the affinity of dopamine agonists for dopamine receptors. Allopurinol increases adenosine levels in the brain, and hence is hypothesized to reduce the symptoms of mania.