Clozapine Is Better Tolerated in Younger Patients: Risk Factors for Discontinuation from a Nationwide Database in Japan

Objective@#The effectiveness of clozapine is clearly superior to other antipsychotics in the treatment of refractory schizophrenia. Clozapine leads to various side effects, and therefore many patients are forced to discontinue. In this study, we analyzed the registry database of all cases in Japan to identify risk factors for discontinuation of clozapine. @*Methods@#The Clozaril patient monitoring service® (CPMS) database from July 31, 2009 to January 26, 2020 was acquired. We defined the following exclusion criteria: patients who had ever taken clozapine by a non-CPMS method, such as an individual import or clinical trial, patients who did not receive clozapine after being enrolled in CPMS, and patients with initial doses other than 12.5 mg (outside the current protocol). Therefore, all patients in this study are new users. Multivariate Cox regression analysis was used to investigate independent risk factors associated with time to discontinuation of clozapine. @*Results@#We identified 8,263 patients as the study population. Clozapine discontinuation was significantly associated with age 40 and older [hazard ratio (HR)=1.66, p<0.001], intolerance to olanzapine (HR=1.31, p=0.018), previous treatment with clozapine (HR=1.30, p=0.001), and leukocyte counts <6,000/mm3 (HR=1.24, p<0.001). The Kaplan-Meier curves for clozapine discontinuation by age group revealed that older age at the time of clozapine introduction tended to have lower continuation rates. @*Conclusion@#Careful administration is important because patients with these factors have a high risk of discontinuation. In addition, the initiation of clozapine during the younger period was more effective and more tolerated.

fNIRS Assessment during an Emotional Stroop Task among Patients with Depression: Replication and Extension

OBJECTIVE: Accumulated evidence collected via functional near-infrared spectroscopy (fNIRS) has been reported with regard to mental disorders. A previous finding revealed that emotional words evoke left frontal cortex activity in patients with depression. The primary aim of the current study was to replicate this finding using an independent dataset and evaluate the brain region associated with the severity of depression using an emotional Stroop task. METHODS: Oxygenized and deoxygenized hemoglobin recording in the brain by fNIRS on 14 MDD patients and 20 normal controls. RESULTS: Hyperactivated oxygenized hemoglobin was observed in the left frontal cortex on exposure to unfavorable stimuli, but no significant difference was found among patients with depression compared with healthy controls on exposure to favorable stimuli. This result is consistent with previous findings. Moreover, an evoked wave associated with the left upper frontal cortex on favorable stimuli was inversely correlated with the severity of depression. CONCLUSION: Our current work using fNIRS provides a potential clue regarding the location of depression symptom severity in the left upper frontal cortex. Future studies should verify our findings and expand them into a precise etiology of depression.