Atypical Antipsychotic–Induced Akathisia with Depression: Therapeutic Role of Mirtazapine

Abstract

Objective: To investigate the efficacy of mirtazapine in treating akathisia caused by risperidone and olanzapine, as well as its use in alleviating comorbid depressive disorder. Case Summaries: Five patients with diagnoses varying from schizophrenia, delusional disorder, and bipolar disorder developed akathisia while on treatment with olanzapine and risperidone. The likelihood that risperidone and olanzapine had induced akathisia in all patients was rated probable according to the Naranjo probability scale. Four of these patients were also found to be depressed. The akathisia was successfully treated with mirtazapine, and 3 of the 4 depressed patients improved with mirtazapine treatment. Use of mirtazapine did not result in any adverse effect. Discussion: Mirtazapine is a potent antagonist of central α2 auto- and hetero-adrenergic receptors, as well as an antagonist of 5-HT2A/2C, 5-HT3, and histaminergic H1 postsynaptic receptors. The efficacy of mirtazapine in treatment of akathisia may result from its antagonist property at the H1 receptors and its dopaminergic activity in frontal cortex. The use of mirtazapine offers advantages over other antiakathisia drugs in its better adverse effect profile, as well as its ability to treat coexisting depression. Conclusions: Mirtazapine is efficacious in treating atypical antipsychotic–induced akathisia. It may be a good option, particularly in patients with coexisting depression.