The descriptive term behavioral and psychological symptoms of dementia (BPSD) is used to cover a range of noncognitive disturbances including anxiety, depression, irritability, aggression, agitation, eating disorders, and inappropriate social or sexual behaviors. Behavioral and psychological symptoms of dementia are seen in about 90% of patients with dementia. We aimed to compare the efficacy and tolerability of risperidone, yokukansan, and fluvoxamine used for BPSD in elderly patients with dementia. Ninety inpatients with dementia according to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria were investigated in Sato Hospital, Koutokukai. We conducted an 8-week, rater-blinded, randomized trial, administering flexibly dosed risperidone, yokukansan, or fluvoxamine. Primary outcome measures were Neuropsychiatric Inventory in Nursing Home Version total score and its items. Secondary outcome measures were cognitive function measured by Mini-Mental State Examination and daily life function measured by Functional Independence Measure (FIM). Neurological adverse effects were measured by the Drug-Induced Extra-Pyramidal Symptoms Scale. At the end of the study, we analyzed 76 patients (92.7%). Mean Neuropsychiatric Inventory in Nursing Home Version total score decreased in all 3 drug groups, with no significant between-group differences. Mini-Mental State Examination and Functional Independence Measure scores did not change significantly. Drug-Induced Extra-Pyramidal Symptoms Scale scores did not change in the yokukansan and fluvoxamine groups, but increased significantly in the risperidone group. Risperidone, yokukansan, and fluvoxamine were equally effective in the treatment of BPSD in elderly patients. However, yokukansan or fluvoxamine for BPSD showed a more favorable profile in tolerability compared with risperidone. This trial is registered at UMIN Clinical Trials Registry (identifier: UMIN000006146).

Although three drugs, risperidone, yokukansan, and fluvoxamine, have shown equal efficacy in treating behavioral and psychological symptoms of dementia (BPSD) in our previous study, their mechanisms of action are different from one another. Monoamines have attracted attention for their key roles in mediating several behavioral symptoms or psychological symptoms through synaptic signaling. We aimed to clarify the monoamines changed by treatment with each drug in patients with BPSD. The main purpose of this study was to determine whether plasma levels of catecholamine metabolites are correlated with pharmacological treatments. This was an 8-week, rater-blinded, randomized, flexible-dose, triple-group trial. In total, 90 subjects were recruited and subsequently three different drugs were allocated to 82 inpatients with BPSD. We examined BPSD data from patients who completed 8 weeks of treatment. Eventually, we analyzed 42 patients (yokukansan: 17; risperidone: 9; fluvoxamine: 16). Homovanillic acid, a metabolite of dopamine, and 3-methoxy-4-hydroxyphenylglycol, a metabolite of noradrenaline, in their plasma were analyzed by high-performance liquid chromatography with electrochemical detection. All three drugs showed equal significant efficacy between baseline and study endpoint. By contrast, biomarkers showed mutually different changes. Patients in the yokukansan group had significantly decreased plasma homovanillic acid levels from baseline. Conversely, patients in the risperidone and fluvoxamine groups exhibited no significant changes in plasma homovanillic acid levels from baseline. Yokukansan contains geissoschizine methyl ether, which is known to have a partial agonist effect on dopamine D2 receptors. An improvement in BPSD condition with the intake of yokukansan is suggested to occur through a suppressed dopaminergic function, which is similar to the effect of aripiprazole.