Real-World Effectiveness of High-Dose Olanzapine and Clozapine for Treatment-Resistant Schizophrenia in Japan: A Retrospective Bidirectional Mirror-Image Study.

BACKGROUND: Clozapine is considered the gold standard medication for treatment-resistant schizophrenia (TRS). However, given that clozapine treatment is associated with the burden of regular blood monitoring and the risk of life-threatening adverse effects, high-dose olanzapine can serve as an alternative treatment. We conducted a bidirectional mirror-image study to evaluate the effectiveness of high-dose olanzapine compared with clozapine. METHODS: We included patients with TRS who switched from olanzapine to clozapine or switched from clozapine to olanzapine, and received high-dose (>20 mg/d) olanzapine treatment for ≥4 weeks at Yamanashi Prefectural Kita Hospital. We obtained data on hospitalization, seclusion, and modified electroconvulsive therapy (mECT) during the clozapine phase and the olanzapine phase. RESULTS: A total of 44 patients were included. When patients switched from high-dose olanzapine to clozapine (n = 32), significant reductions were found in the total days of seclusion, the total number of mECT, and the number of patients who received mECT at least once. When patients switched from clozapine to high-dose olanzapine (n = 12), a significant reduction was found in the number of patients who received mECT at least once. When data from both directions of treatment were combined, significant reductions were found in the total days of seclusion, the total number of mECT, and the number of patients who received mECT at least once in favor of clozapine. CONCLUSIONS: Findings suggest that high-dose olanzapine may not be as effective as clozapine for patients with TRS in real-world practice. However, it should be noted that there are unique circumstances that restrict the use of clozapine in Japan.

Mortality in patients with schizophrenia in Japan.

PURPOSE: Patients with schizophrenia have a higher mortality risk than the general population. However, no recent studies have investigated mortality in patients with schizophrenia in Japan. Therefore, we conducted a retrospective study to evaluate excess mortality and risk factors for mortality in patients with schizophrenia in Japan. METHODS: We included patients diagnosed with schizophrenia or schizoaffective disorder at Yamanashi Prefectural Kita Hospital between January 1, 2013, and December 31, 2017. Standardized mortality ratios (SMRs) were used to compare mortality rates between patients with schizophrenia and the general population. Logistic regression analysis was performed to estimate risk factors associated with mortality. RESULTS: Of the 1,699 patients with schizophrenia (893 men and 806 women), 104 (55 men and 49 women) died during the study period. The all-cause SMR (95% confidence interval [CI]) was 2.18 (1.76-2.60); the natural- and unnatural-cause SMRs were 2.06 (1.62-2.50) and 5.07 (2.85-7.30), respectively. Men (adjusted odds ratio [OR] = 2.24, 95% CI = 1.10-4.56), age (adjusted OR = 1.12, 95% CI = 1.09-1.16), and barbiturate use (adjusted OR = 8.17, 95% CI = 2.07-32.32) were associated with the risk of mortality. CONCLUSION: The mortality rate remains high in patients with schizophrenia in Japan. Further studies are needed to evaluate mortality trends in this population.

Appendicitis Associated With Clozapine: Analyses Based on a Spontaneous Reporting System Database in Japan.

BACKGROUND: An association between appendicitis and clozapine has recently been reported; however, few studies other than case reports have investigated this association. Therefore, we aimed to investigate the association between appendicitis and clozapine, using a large spontaneous reporting database in Japan. METHODS: Japanese Adverse Drug Event Report data were used in this study, and patients who had received clozapine or nonclozapine second-generation antipsychotics (NC-SGAs) available in Japan were included. To compare the reporting frequency of appendicitis associated with clozapine and NC-SGAs, we calculated the adjusted reporting odds ratio using logistic regression models, adjusting for age group, sex, and anticholinergic use. We conducted a time-to-event analysis to examine the time to onset of appendicitis associated with clozapine. RESULTS: In total, 8921 patients were included in this study, of whom 85 (1.0%) had appendicitis. Of these, 83 patients had received clozapine. Appendicitis was significantly more frequently reported with clozapine than with NC-SGAs. Time-to-event analysis showed that the risk of developing appendicitis associated with clozapine increased over time. CONCLUSIONS: Clozapine was associated with a higher risk of appendicitis than NC-SGAs, which increased with time. These findings suggest that clinicians need to pay greater attention to the risk of developing appendicitis during clozapine treatment.

Combination Therapy of Long-Acting Injectable Second-Generation Antipsychotics and Oral Antipsychotics: A Retrospective Chart Review and Prescribers' Attitude Survey.

BACKGROUND: Although long-acting injectable antipsychotics (LAI-APs) have been considered as a monotherapeutic option in the maintenance treatment of schizophrenia, it has been recently reported that the combination therapy of LAI-APs and oral antipsychotics (OAPs) is common. METHODS: We conducted a retrospective chart review to examine the situation of the combination therapy of LAI second-generation antipsychotics (LAI-SGAs) and OAPs, and a questionnaire survey to investigate prescribers' attitudes toward the combination therapy. We included patients who received any LAI-SGAs for 1 month or longer and classified them into monotherapy and combination therapy groups. We collected information on age, sex, primary psychiatric diagnosis, and concomitant psychotropic medications. RESULTS: Of the 132 patients, 39 (29.5%) received the combination therapy of LAI-SGAs and OAPs. Long-acting injectable risperidone was significantly associated with receiving the combination therapy compared with LAI aripiprazole. Olanzapine was the most common OAP in combination with LAI-SGAs. Only 8 patients (20.5%) concurrently received the same type of OAPs as LAI-SGAs. More than 60% of the patients received OAP polypharmacy before the initiation of LAI-SGAs. The psychiatrists in charge prescribed LAI-SGAs mainly because of a concern about adherence, and OAPs mainly because of insufficient dose of LAI-SGAs, to patients in the combination therapy group. They estimated that adherence to OAPs in two thirds of the patients in the combination therapy group was 80% or higher. CONCLUSIONS: The present study showed that the combination therapy of LAI-SGAs and OAPs is often conducted in real-world clinical practice. Considering the reason for the introduction of LAI-APs, clinicians should carefully monitor patients' adherence to OAPs concurrently used with LAI-APs.

Clozapine Once-Daily Versus Divided Dosing Regimen: A Cross-sectional Study in Japan.

OBJECTIVE: Clozapine is generally recommended to be prescribed in a divided dosing regimen based on its relatively short plasma half-life. However, there has been little evidence to support the superiority of divided dosing of clozapine over once-daily dosing. To our knowledge, there have been no studies examining differences in actual plasma concentrations or adverse effects between the 2 dosing strategies of clozapine. We aimed to compare actual plasma concentrations of clozapine between once-daily and divided dosing regimens, and to examine the relationships of these regimens with psychiatric symptoms and adverse effects of clozapine. METHODS: We analyzed data from 108 participants of a previous study conducted in 2 hospitals in Japan. A population pharmacokinetic model was used to estimate the peak and trough plasma concentrations of clozapine based on actual plasma concentrations. We evaluated psychiatric symptoms with the Brief Evaluation of Psychosis Symptom Domains and adverse effects of clozapine with the Glasgow Antipsychotic Side-effects Scale for Clozapine. RESULTS: The estimated peak and trough plasma concentrations of clozapine did not differ significantly between once-daily and divided dosing regimens. There were no significant differences in psychiatric symptoms except for depression/anxiety or subjective adverse effects of clozapine between the 2 dosing strategies. CONCLUSIONS: Our findings tentatively support the feasibility and clinical utility of once-daily dosing of clozapine in clinical practice. Further studies are needed to replicate these findings and determine causality between dosing strategies and clinical outcomes.

Clinical Outcomes after Clozapine Discontinuation in Patients with Schizophrenia: A Systematic Review.

INTRODUCTION: Clozapine is the gold standard of treatment for patients with treatment-resistant schizophrenia. However, approximately 60% of those patients do not respond to clozapine; moreover, clinical outcomes after clozapine discontinuation are unclear so far. Therefore, we conducted a systematic review to clarify the outcomes after clozapine discontinuation. METHODS: A systematic literature search was conducted, using MEDLINE and Embase with the following keywords: (clozapine AND (cessation* OR cease* OR withdraw* OR discontinu* OR halt* OR stop* OR switch*) AND (schizophreni* OR schizoaffective)). RESULTS: A total of 28 clinical studies from 27 articles were identified and included in this systematic review. Three randomized controlled trials reported worsening of psychiatric symptoms. In 10 single-arm studies, the results of worsening and improving psychiatric symptoms were inconsistent. In one large retrospective cohort study, clozapine rechallenge, olanzapine, and antipsychotic polypharmacy had lower rehospitalization rates compared to no medication after clozapine discontinuation. In the other 14 retrospective studies, the vast majority showed worsening of clinical status after clozapine discontinuation. Among five studies on clinical outcomes after clozapine rechallenge, four reported improvements in clinical status in more than half of patients who rechallenged clozapine. The remaining study reported that the clozapine discontinuation-rechallenge group had a worse remission assessment score than the clozapine discontinuation-no rechallenge group. DISCUSSION: Clinical outcomes generally worsen after clozapine discontinuation. Clozapine rechallenge and olanzapine may be considered following clozapine discontinuation. The outcomes after clozapine discontinuation in clozapine non-responders remain inconclusive; therefore, well-designed studies are warranted.

Olanzapine Reduction From High Dose to Standard Dose: A Retrospective Chart Review.

PURPOSE/BACKGROUND: Although high-dose olanzapine might be a treatment option in patients with treatment-resistant schizophrenia, it can be reduced to the standard dose after symptoms are stabilized. We examined the rate of olanzapine reduction from high to standard dose and whether this change was successful. METHODS/PROCEDURES: We included patients who received high-dose olanzapine (>20 mg/d) for 4 weeks or longer at our hospital. First, we retrospectively followed the patients for 6 years and estimated the percentage of those whose olanzapine was reduced from high to standard dose. Second, we followed patients who received olanzapine reduction for 1 year and estimated the rate of success based on the study-defined criteria for unsuccessful reduction. We also explored factors associated with the dose reduction and successful results. FINDINGS/RESULTS: Among 110 patients who received high-dose olanzapine treatment, 72 had their olanzapine dose reduced to the standard dose for 6 years; the duration of high-dose olanzapine treatment was significantly and negatively associated with a reduction in olanzapine (hazard ratio, 0.98; 95% confidence interval, 0.98-0.99). Among the patients whose olanzapine was reduced, 50 achieved successful reduction for 1 year. Among the reasons for the reduction, an unknown reason was significantly associated with successful reduction (hazard ratio, 4.93; 95% confidence interval, 1.55-22.8). IMPLICATIONS/CONCLUSIONS: The findings suggest that high-dose olanzapine can be reduced to the standard dose after stabilization of symptoms in most patients with schizophrenia.

A systematic review and pooled, patient-level analysis of predictors of mortality in neuroleptic malignant syndrome.

OBJECTIVE: Neuroleptic malignant syndrome (NMS) is a potentially fatal, idiosyncratic reaction to antipsychotics. Due to low incidence of NMS, research on risk factors of mortality associated with NMS is limited. METHODS: Two authors independently searched Medline/Embase/Cochrane/CINAHL/PsychINFO databases for case reports with author-defined NMS published in English until 05/30/2020. Demographic, clinical, treatment, and outcome data were independently extracted following PRISMA guidelines. NMS severity was rated using the Francis-Yacoub scale. Mortality risk factors were identified using a multivariable regression analysis including all characteristics that were significantly different between NMS cases resulting vs. not resulting in death. RESULTS: 683 cases with NMS were analyzed (median age = 36 years, males = 62.1%). In a multivariable model, independent predictors of NMS mortality were lack of antipsychotic discontinuation (odds ratio (OR) = 4.39 95% confidence interval (CI) = 2.14-8.99; p < 0.0001), respiratory problems (OR = 3.54 95%CI = 1.71-7.32; p = 0.0004), severity of hyperthermia (Unit-OR = 1.30, 95%CI = 1.16-1.46; p < 0.0001), and older age (Unit-OR = 1.05, 95%CI = 1.02-1.07; p = 0.0014). Even in univariate, patient-level analyses, antipsychotic formulation was not related to death (oral antipsychotic (OAP): n = 39/554 (7.0%) vs. long-acting injectable (LAI): n = 13/129 (10.1%); p = 0.2413). Similarly, death with NMS was not related to antipsychotic class (first-generation antipsychotic: n = 38/433 (8.8%) vs. second-generation antipsychotic: n = 8/180 (4.4%); p = 0.0638). Non-antipsychotic co-treatments were not associated with NMS mortality. CONCLUSION: Despite reliance on case reports, these findings indicate that presence of respiratory alterations, severity of hyperthermia, and older age should alert clinicians to a higher NMS mortality risk, and that antipsychotics should be stopped to reduce mortality, yet when NMS arises on LAIs, mortality is not increased vs. OAPs.

Long-Acting Injectables Versus Oral Antipsychotics: A Retrospective Bidirectional Mirror-Image Study.

PURPOSE: Mirror-image studies, which compare equal periods of time before and after a new treatment is introduced, may reflect the real-world impact of that treatment. However, most mirror-image studies that have investigated the impact of long-acting injectable antipsychotics (LAIs) were unidirectional in design, for patients switching from oral antipsychotics (OAPs) to LAIs. Therefore, we conducted a bidirectional mirror-image study comparing LAIs and OAPs. METHODS: We included 126 schizophrenia or schizoaffective disorder patients' LAI treatment data from 3 psychiatric hospitals. Patients took OAPs for 6 months or more before initiating LAIs, or the reverse. We obtained data on the number of hospitalizations as a primary outcome, plus the total duration and mean duration of hospitalization as secondary outcomes during the 6 months of the patients' first treatment, and the 6 months after the patients started their second type of treatment. RESULTS: The results indicated that there was no significant difference in any outcomes between LAI and OAP treatment when going from LAIs to OAPs (n = 59). However, when patients started with OAPs and switched to LAIs (n = 67), they were hospitalized a significantly fewer number of times, and the duration of their stays was shorter in the LAI phase than in the OAP phase. When combined with bidirectional data, LAI superiority was still observed. CONCLUSIONS: The findings endorse the relative effectiveness of LAIs over OAPs in the real world, although the inherent flaws of mirror-image studies such as expectation bias and having no parallel comparator should be considered.

Effect of Clozapine vs Other Second-Generation Antipsychotics on Hospitalization and Seclusion: A Retrospective Mirror-Image Study in a Japanese Public Psychiatric Hospital.

BACKGROUND: Clozapine has been regarded as the gold standard for patients with treatment-resistant schizophrenia, but a recent network meta-analysis has questioned its relative superiority over other second-generation antipsychotics (SGAs) such as olanzapine and risperidone. PURPOSE: We conducted a retrospective mirror-image study of clozapine vs other SGAs to evaluate real-world effectiveness of clozapine in terms of the duration of hospitalization and seclusion, both of which represent a critical outcome. METHODS: We included all patients who initiated clozapine at the Yamanashi Prefectural KITA Hospital and had continued to take any SGA(s) other than clozapine for at least 1 year before the initiation of clozapine. We obtained data on hospitalization and seclusion during 1 year of SGA treatment (SGA phase) and 1 year after the treatment was switched to clozapine (clozapine phase). RESULTS: The study included 35 patients (21 men, 31 with schizophrenia, 4 with schizoaffective disorder) with the average ± SD age of 37.3 ± 11.1 years. The results indicated that total hospitalization days did not differ significantly between SGA and clozapine treatment. However, total duration of seclusion was significantly shorter in the clozapine phase than in the SGA phase. Furthermore, the number of patients who were secluded at least once was significantly smaller in the clozapine phase than in the SGA phase. The results were essentially unchanged when outlier patients were excluded and only when patients taking olanzapine and/or risperidone during the SGA phase were considered. CONCLUSIONS: Although the findings from this retrospective analysis need to be further tested in prospective trials, they endorse the relative effectiveness of clozapine over other SGAs in the real world.

Tardive Dyskinesia and Long-Acting Injectable Antipsychotics: Analyses Based on a Spontaneous Reporting System Database in Japan.

Objective: This study compared the reporting frequency of tardive dyskinesia (TD) between long-acting injectable antipsychotics (LAI-APs) and the equivalent oral antipsychotics (O-APs), LAI first-generation antipsychotics (LAI-FGAs) and LAI second-generation antipsychotics (LAI-SGAs), and individual LAI-APs.Methods: The Japanese Adverse Drug Event Report was used in this study, and data were obtained from April 2004 to February 2021. Patients who received LAI-APs available in Japan (LAI haloperidol, LAI fluphenazine, LAI aripiprazole, LAI risperidone, and LAI paliperidone) or the equivalent O-APs were included in this study. We calculated the adjusted reporting odds ratios (aRORs) to compare the reporting frequency of TD.Results: A total of 8,425 patients were included in the study. TD was reported significantly less frequently with LAI paliperidone than with oral paliperidone (aROR [95% confidence interval (CI)] = 0.13 [0.05-0.36]). Other LAI-APs were associated with a numerically lower reporting frequency of TD than the equivalent oral SGAs. The reporting frequency of TD associated with LAI-SGAs was significantly lower than that of LAI-FGAs (aROR [95% CI] = 0.18 [0.08-0.43]). All LAI-SGAs were significantly associated with a lower reporting frequency of TD than that of LAI fluphenazine (aROR [95% CI]: LAI aripiprazole, 0.11 [0.04-0.35]; LAI risperidone, 0.09 [0.03-0.32]; LAI paliperidone, 0.02 [0.005-0.09]). and LAI haloperidol, 8.58 [1.85-39.72]). LAI fluphenazine was significantly associated with a higher reporting frequency of TD than LAI haloperidol (aROR [95% CI] = 8.58 [1.85-39.72]). The reporting frequency of TD associated with LAI paliperidone was significantly lower than that with LAI aripiprazole (aROR [95% CI] = 0.18 [0.05-0.73]).Conclusions: Compared to O-APs, LAI-APs, particularly LAI-SGAs, may be associated with a lower risk of TD.

Real-world effectiveness of antipsychotic treatments in 1011 acutely hospitalized patients with schizophrenia: A one-year follow-up study.

PURPOSE: To compare the real-world effectiveness of antipsychotic treatments focusing on long-acting injectable antipsychotic medications (LAIs) and antipsychotic polytherapies except polytherapy involving clozapine (APEC) for patients with schizophrenia. METHODS: This prospective study was conducted over a 19-month period in 12 psychiatric emergency hospitals in Japan. Patients who were newly admitted to psychiatric emergency wards between September 2019 and March 2020 because of acute onset or exacerbation of Schizophrenia and Other Psychotic Disorders as defined by the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, were included. All patients were followed for one-year after discharge or until March 31, 2021. The primary outcome was the risk of treatment failure defined as psychiatric rehospitalization, discontinuation of medication, death, or continuation of hospitalization for one year. Cox proportional hazards multivariate regression was used for analyses. RESULTS: A total of 1011 patients were enrolled (women, 53.7%; mean [SD] age, 47.5 [14.8] years). During follow-up, 588 patients (58.2%) experienced treatment failure including rehospitalization (513 patients), discontinuation of medication (17 patients), death (11 patients), and continuation of hospitalization for one-year (47 patients). Switching to LAIs (hazard ratio [HR] 0.810, 95%CI 0.659-0.996) and APEC (HR 0.829, 95%CI 0.695-0.990) were significantly associated with a low rate of treatment failure. CONCLUSIONS: Switching to LAIs and APEC in early non-responders seems to be beneficial for the prevention of treatment failure in acutely admitted patients with schizophrenia. The risk of treatment failure was about 19% and 17% lower in patients treated with LAIs and APEC, respectively, than in patients treated without them.

Is antipsychotic polypharmacy associated with metabolic syndrome even after adjustment for lifestyle effects?: a cross-sectional study.

BACKGROUND: Although the validity and safety of antipsychotic polypharmacy remains unclear, it is commonplace in the treatment of schizophrenia. This study aimed to investigate the degree that antipsychotic polypharmacy contributed to metabolic syndrome in outpatients with schizophrenia, after adjustment for the effects of lifestyle. METHODS: A cross-sectional survey was carried out between April 2007 and October 2007 at Yamanashi Prefectural KITA hospital in Japan. 334 patients consented to this cross-sectional study. We measured the components consisting metabolic syndrome, and interviewed the participants about their lifestyle. We classified metabolic syndrome into four groups according to the severity of metabolic disturbance: the metabolic syndrome; the pre-metabolic syndrome; the visceral fat obesity; and the normal group. We used multinomial logistic regression models to assess the association of metabolic syndrome with antipsychotic polypharmacy, adjusting for lifestyle. RESULTS: Seventy-four (22.2%) patients were in the metabolic syndrome group, 61 (18.3%) patients were in the pre-metabolic syndrome group, and 41 (12.3%) patients were in visceral fat obesity group. Antipsychotic polypharmacy was present in 167 (50.0%) patients. In multinomial logistic regression analyses, antipsychotic polypharmacy was significantly associated with the pre-metabolic syndrome group (adjusted odds ratio [AOR], 2.348; 95% confidence interval [CI], 1.181-4.668), but not with the metabolic syndrome group (AOR, 1.269; 95%CI, 0.679-2.371). CONCLUSIONS: These results suggest that antipsychotic polypharmacy, compared with monotherapy, may be independently associated with an increased risk of having pre-metabolic syndrome, even after adjusting for patients' lifestyle characteristics. As metabolic syndrome is associated with an increased risk of cardiovascular mortality, further studies are needed to clarify the validity and safety of antipsychotic polypharmacy.

Clinical outcomes after clozapine discontinuation in responders versus nonresponders: a retrospective chart review.

No studies have compared clinical outcomes after discontinuation of clozapine between patients who responded to clozapine and those who did not. Therefore, we examined 1-year clinical outcomes after clozapine discontinuation in responders and nonresponders. We reviewed data on patients who discontinued clozapine and retrospectively followed them for 1 year. Clinical information was collected from medical records starting at the initiation of clozapine administration, at discontinuation and at 1 year after discontinuation. In addition, clinical status was assessed using the Clinical Global Impression - Severity (CGI-S) and Clinical Global Impression - Improvement (CGI-I) scales. We classified the patients into clozapine responder and nonresponder groups according to the CGI-I score. Thirty-nine patients were enrolled in this study. Olanzapine was the most common antipsychotic prescribed after clozapine discontinuation in both the responder and nonresponder groups. The mean CGI-S score significantly increased 1 year after clozapine discontinuation in the responder group and significantly decreased in the nonresponder group; there was a significant difference in changes in the CGI-S scores between the groups. The difference remained significant after controlling for clozapine dose and duration of treatment. The findings suggest that clinicians may consider continuing and discontinuing clozapine treatment for patients who responded to clozapine and those who did not, respectively.

Neuroleptic malignant syndrome associated with long-acting injectable versus oral second-generation antipsychotics: Analyses based on a spontaneous reporting system database in Japan.

Long-acting injectable antipsychotics (LAI-APs) remain underutilized. One reason is the concern that LAI-APs might cause serious adverse events such as neuroleptic malignant syndrome (NMS) and lead to prolonged symptoms compared with oral treatment. Because the risk of NMS associated with LAI second-generation antipsychotics (LAI-SGAs) remains unclear, we compared reporting frequency, time to onset, and mortality of NMS between LAI- and oral SGAs using data from a Japanese spontaneous adverse event reporting database between April 2004 and September 2019. Of 5791 patients reporting adverse events due to LAI-SGAs or the equivalent oral SGAs, 768 (13%) developed NMS. LAI aripiprazole and LAI paliperidone were associated with a significantly lower reporting frequency of NMS than the equivalent oral SGAs (adjusted reporting odds ratio [95% confidence interval]: 0.35 [0.19-0.63] and 0.40 [0.27-0.59], respectively). Between 42% and 62% of the NMS associated with LAI- and oral SGAs other than LAI risperidone occurred within 30 days after initiation. The proportion of mortality due to NMS associated with oral aripiprazole was 13.1% and no deaths occurred in patients with NMS associated with LAI aripiprazole. The proportions of mortality due to NMS associated with oral risperidone/paliperidone, LAI risperidone, and LAI paliperidone were 8.8%, 4.2%, and 3.4%, respectively. Our findings showed that LAI-SGAs were not associated with a higher reporting frequency and mortality of NMS compared with oral SGAs, although clinicians need to closely monitor the occurrence of NMS not only during oral SGA treatment, but also, and in particular, in the early stage of LAI-SGA treatment.

Risk of withdrawal of consent for treatment with long-acting injectable versus oral antipsychotics: A meta-analysis of randomized controlled trials.

BACKGROUND: Despite the clinical importance of antipsychotic long-acting injections (LAIs) in the treatment of schizophrenia, their use may be limited by patients' reluctance to accept the injections. No studies to date have investigated whether patients are more likely to withdraw their consent to treatment with LAIs than to treatment with oral antipsychotics (OAPs). Therefore, we performed a meta-analysis of randomized controlled trials (RCTs) to compare the risk of withdrawal of consent between the 2 routes of administration. METHODS: PubMed, the Cochrane Library, PsycINFO, and CINAHL were systematically searched. RCTs with open-label or rater-masked design that compared LAIs with OAPs were selected. Data on study discontinuation due to withdrawal of consent and/or loss to follow-up were extracted. RESULTS: A total of 16 studies (4815 patients) that met the study eligibility criteria were included in the meta-analysis. There was no significant difference between the LAI and OAP groups in the risk of cessation of treatment because of withdrawal of consent. Similarly, there was no significant difference in the risk of study discontinuation because of withdrawal of consent plus loss to follow-up. CONCLUSIONS: These findings were unexpected and suggest that patients may not be more hesitant to continue LAIs than OAPs after consenting to or receiving treatment. Nevertheless, patients should be provided detailed explanations about the use of LAIs and a support system that encourages them to continue treatment.

Development of diagnostic criteria and severity scale for polydipsia: A systematic literature review and well-experienced clinicians' consensus.

Despite the clinical importance of polydipsia, no diagnostic criteria or severity scales that comprehensively assess this condition are available. Thus, we aimed to develop diagnostic criteria and a severity scale for polydipsia based on a systematic review and well-experienced clinicians' consensus. We performed a systematic review, identified 27 studies related to diagnostic criteria or severity classification for polydipsia, and extracted items used to assess polydipsia in these studies. Ten well-experienced clinicians-5 psychiatrists and 5 nurses-participated in the Delphi method. They evaluated 39 items extracted based on the results of the systematic review regarding (1) their necessity in diagnosing and assessing the severity of polydipsia, and (2) their relative importance rated on 7-point scale among the items included in the severity scale. The Polydipsia Diagnostic Criteria (PDC) included 4 essential items-excessive drinking, low serum sodium level or low serum osmolality, abnormal normalized diurnal weight gain, and low urine specific gravity-based on consensus reached using the Delphi method. The Polydipsia Severity Scale (PSS) included 13 items with a maximum score of 59. The first diagnostic criteria and symptom scale for polydipsia were developed based on the findings of a systematic review and well-experienced clinicians' consensus.