Usefulness of Low-Dose Olanzapine for Initial and Maintenance Treatments of Very-Late-Onset Schizophrenia-Like Psychosis: A Case Report

In pharmacotherapy for schizophrenia, it is recommended that antipsychotic medications should not be discontinued, and their dosage should not be reduced during the stabilization and maintenance phases. Nevertheless, these drugs also have side effects that can increase extrapyramidal symptoms and mortality in the elderly population. It is yet to be determined whether antipsychotics should be reduced or discontinued in patients with very-late-onset schizophrenia-like psychosis (VLOSLP) during the stabilization and maintenance stages. Therefore, we describe the case of an elderly woman for whom low-dose olanzapine was useful throughout the initial, stabilization, and maintenance phases of VLOSLP. The patient was a 70-year-old woman who had experienced persistent hallucinations and delusions for 3 years. Two years after her diagnosis, except for relapse due to self-discontinuation, she remained in remission of her psychotic symptoms by continuing olanzapine treatment (2.5 mg/day). The standard effective dose of olanzapine was 10 mg/day, and she was able to respond to therapy with a low dose of olanzapine in the initial and subsequent phases of stabilization and maintenance. It is suggested that the discontinuation of antipsychotics should be avoided to avoid recurrence, even if the dose is lower than the standard amount during the stabilization and maintenance phases. Additionally, if the patient progresses to dementia, the treatment approach may vary, and it is imperative to monitor cognitive decline and self-discontinuation of oral medications during the follow-up of VLOSLP.