Addition of lithium to haloperidol in non-affective,antipsychotic non-responsive schizophrenia: a double blind,placebo controlled,parallel design clinical trial

This double-blind placebo controlled, parallel design clinical trial compared the therapeutic effects of the addition of lithium or placebo to haloperidol in 21 seriously ill state hospital patients with DSM-III-R schizophrenia, who did not have concurrent affective disorders and who had not responded to previous trials of conventional antipsychotic medication. During a baseline period of 6 weeks, patients were switched to a stable dose of haloperidol (mean ± SD dose=13.6±8.1 mg/day). Patients were then randomized to receive either lithium or placebo in addition to haloperidol for 8 weeks (mean ± SD lithium level =0.98±0.13 mEq/1). Symptoms and side effects were assessed weekly. Improvement in symptoms correlated with the non-blind adjustment of antipsychotic dose, but not with lithium or placebo treatment. Side effects ratings did not differ between the two groups, but one patient developed a reversible delirium associated with combined lithium/haloperidol treatment. For these long-term, severely ill patients, combined treatment afforded no advantage over treatment with haloperidol alone.Supported by Grant MH 46700 from the National Institute for Mental Health. Lithium and lithium placebo capsules were supplied by Lilly Pharmaceuticals