Toshihiko Matsumoto

• MD, PhD
• Managing Director at National Center of Neurology and Psychiatry

Aim This study evaluated survival rates and examined characteristics associated with mortality among individuals with drug use disorder (DUD) enrolled in drug addiction rehabilitation facilities in Japan. Methods This longitudinal cohort study, conducted from October 2016 to October 2021, followed 361 individuals with DUD residing in drug addictio...

BACKGROUND Digital mental health approaches offer a novel means to monitor and reduce harms associated with substance use in daily life. However, limited evidence exists on their application to methamphetamine (METH) use, particularly regarding individual variability in physiological responses and psychological conditions. OBJECTIVE This study aim...

Background Treatment of stimulant offenders in Japan is an urgent issue. One of the more recent support approaches for stimulant offenders in Japan is to understand and support them based on a self‐medication hypothesis; however, the effect of trust on substance abuse severity among incarcerated stimulant offenders has not been examined. Additional...

Aim To analyze the drinking habits of individuals who overdosed on over‐the‐counter (OTC) drugs, such as cough suppressants, antitussives, antipyretic analgesics, and combination cold medications, in Japan. Methods This cross‐sectional study analyzed data collected from 2881 participants through a national survey conducted in Japan in 2023. Throug...

Background Methamphetamine use is related to severe health, social, and criminal challenges. However, there is limited evidence regarding the factors associated with the recurrence of drug use among individuals who have used methamphetamine, particularly within populations involved in the criminal justice system. This study aimed to identify predic...

Aim This study aims to investigate how the coronavirus disease (COVID‐19) pandemic impacted service provision of peer‐supported addiction services, such as self‐help groups or recovery houses and government‐owned addiction healthcare services, in Japan, as well as the quality of their interaction. Methods An online survey was distributed to all 69...

Aim To investigate the epidemiological characteristics of patients presenting to the emergency department with an overdose of over‐the‐counter (OTC) drugs. Methods A questionnaire survey was conducted to examine the sociodemographic characteristics of patients with OTC drugs overdoses visiting emergency departments at eight sites across the countr...

Aim The aim of this study was to examine the characteristics of habitual hypnotic users in Japan. Methods This nationwide, cross‐sectional survey used self‐administered questionnaires. Data were collected from four national surveys conducted every 2 years between 2015 and 2021. The participants were Japanese individuals who had taken prescription...

Background Substance use disorder (SUD) is a major health issue in Indonesia, where several barriers to treatment exist, including inaccessibility to treatment services, stigma, and criminalization of drug issues. Peer involvement and the use of telemedicine to deliver psychotherapy are promising approaches to overcome these barriers. Objective Th...

Aim To investigate changes in the clinical characteristics of patients who abused benzodiazepine receptor agonists (BZRA) or over‐the‐counter (OTC) drugs before and after COVID‐19 based on the 2018 and 2022 data of the “Nationwide Psychiatric Hospital (NPH) Survey on Drug‐related Psychiatric Disorders.” Method A total of 446 and 155 cases, and 435...

Aim To identify situational factors that can predict drug abstention in patients with drug use disorders undergoing residential drug use treatment. Methods Patients with drug use disorders admitted to drug addiction rehabilitation centers (DARCs) in 2016 were involved in this study. Longitudinal panel data were used, with eight follow‐up surveys o...

Objective To examine the clinical characteristics of over‐the‐counter (OTC) drug abusers in psychiatric practice in Japan. Method We examined the attributes, ICD‐10 subcategory, and comorbid mental disorders of patients who mainly abuse OTC products and compared the clinical characteristics of single product and multiple products abusers, using th...

Several causes of drug addiction in people remain unknown. It is known that only a small percentage of those who use potent dependent drugs, such as methamphetamine and heroin, develop addiction. In addition, some studies suggest that the choice of preferred drugs among drug addicts is made proactively according to criteria other than the strength...

Aim Stigma within healthcare settings significantly impact the lives of people who use drugs (PWUD). Given the lack of quantitative data on stigma toward PWUD in healthcare settings and the unknown factors that contribute to it in the Japanese context, this study aimed to investigate the current status of stigma toward PWUD and its determinants. M...

Aim Stigma among healthcare professionals toward people who use drugs (PWUDs) must be addressed for recovery. However, research on this topic is limited in Japan, therefore we developed a brand‐new scale through coproduction with PWUDs to measure stigma and conducted a survey using the developed scale to examine what influences stigma towards PWUDs...

BACKGROUND Substance use disorder (SUD) is a major health issue in Indonesia, where several barriers to treatment exist, including inaccessibility to treatment services, stigma, and criminalization of drug issues. Peer involvement and the use of telemedicine to deliver psychotherapy are promising approaches to overcome these barriers. OBJECTIVE Th...

We analyzed the results of a nationwide questionnaire administered to 699 stimulant offenders and examined sex differences in the association between various psychosocial problems and treatment history for substance use disorder. Based on their attributes, we predominantly evaluated the treatment and support provided to women with substance use dis...

Aim: To determine the risk factors for cannabis use disorders and cannabis psychosis in Japan based on a 2021 online survey among Japanese users of social network services. Methods: The 3142 respondents who had used cannabis within the preceding year were categorized into two groups based on the development of cannabis use disorder and/or cannab...

BACKGROUND Digital health technologies using mobile apps and wearable devices are a promising approach to the investigation of substance use in the real world and for the analysis of predictive factors or harms from substance use. Moreover, consecutive repeated data collection enables the development of predictive algorithms for substance use by ma...

Background: Digital health technologies using mobile apps and wearable devices are a promising approach to the investigation of substance use in the real world and for the analysis of predictive factors or harms from substance use. Moreover, consecutive repeated data collection enables the development of predictive algorithms for substance use by...

Methamphetamine is an illegal drug with the greatest burdens in Japan. Social and medical measures to combat methamphetamine dependence have been implemented, but no reports on changes in the characteristics of methamphetamine use disorder patients have been conducted. We aimed to describe these changes, and provide information on the results of so...

Aim: The effect of a web-based relapse prevention program might vary depending on a specific population if the study participants included drug users with various characteristics. This secondary analysis explored subgroups among Japanese drug users that may benefit from a web-based relapse prevention program. Methods: Outpatients with drug use d...

Introduction: The misuse of stimulant drugs such as methamphetamine is a global public health issue. One important neurochemical mechanism of methamphetamine use disorder may be altered dopaminergic neurotransmission. For instance, previous studies using positron emission tomography (PET) have consistently shown that striatal dopamine D2-type recep...

Background and objectives: Methamphetamine use disorder is the most common reason for psychiatrist visits among illicit drug users in Japan. Although variables associated with methamphetamine use and sex differences have been reported in the United States, Australia, and Asian countries, such studies are rare in Japan. We examined methamphetamine...

Aim: No effective pharmacological interventions have been developed for patients with methamphetamine use disorder. Ifenprodil is a blocker of G protein-activated inwardly rectifying potassium channels, which play a key role in the mechanism of action of addictive substances. We conducted a randomized, double-blind, exploratory, dose-ranging, plac...

Summary: An anonymous online survey was conducted with Japanese cannabis users to better understand cannabis use and possible adverse effects. There were a total of 4,138 survey responses. Respondents that were considered to have had cannabis use disorder were 8.3%. Respondents that had experienced acute intoxication including light to mild cases w...

Aims This study aimed (1) to delineate how a web-based intervention affects the problem drinking behaviors of Japanese adults and (2) to examine the moderating effects of disorder levels and alcohol outcome expectancies on intervention outcomes. Methods We implemented an online two-armed parallel-group randomized controlled trial with 546 Japanese...

Objectives: This study aimed to develop proposed indicators for Sustainable Development Goals section 3.5 (SDGs 3.5) based on existing databases published in Japan. Methods: The following data sources were selected to identify potential indicators because they contained information consistent with the research objectives, the surveys were conducted...

Introduction: Altered dopaminergic neurotransmission, especially in the functioning of dopamine D2-type receptors, is considered central to the etiology of a variety of neuropsychiatric disorders. In particular, individuals with substance use disorders have been consistently observed to exhibit lower D2-type receptor availability (quantified as bin...

Aims: This study aimed (1) to delineate how a web-based intervention affects the problem drinking behaviors of Japanese adults and (2) to examine the moderating effects of disorder levels and alcohol outcome expectancies on intervention outcomes. Methods: We implemented an online two-armed parallel-group randomized controlled trial with 546 Japanes...

Background Substance use disorder (SUD) is a leading contributor to the global burden of disease. In Indonesia, the availability of formal treatment for SUD falls short of the targeted coverage. A standardised therapeutic option for SUD with potential for widespread implementation is required, yet evidence-based data in the country are scarce. In t...

This study aimed to examine the relationship between methamphetamine (MA) use and high-risk sexual behavior among newly incarcerated prisoners in Japan. We conducted a secondary analysis using cross-sectional survey data, which constituted a nationwide prison sample surveyed between July and November 2017. In total, 699 participants (462 male and 2...

This secondary analysis of a pilot randomized controlled trial assessed the usability and acceptability of a web-based relapse prevention and self-monitoring program, which was newly developed for Japanese drug users. We analyzed quantitative and qualitative data using a mixed-method approach among 43 study participants. We assessed the usability o...

Long‐term use of benzodiazepine (BZD) is not recommended for the treatment of anxiety disorders. Cognitive behavioral therapy (CBT) is an effective treatment option for discontinuation of BZDs in patients with anxiety disorders. This systematic review and meta‐analysis sought to clarify whether CBT is effective for discontinuing BZD anxiolytics in...

Background Consuming drugs in conjunction with sexual intercourse may shape the perceived interdependence of drug use and sexual intercourse (PIDS). Additionally, the severity of drug problems may have a significant impact on PIDS. However, this relationship remains unverified. Therefore, this study investigates whether the severity of drug problem...

Background The term “addiction” encompasses both substance dependence and behavioral addiction and is associated with major societal problems. Measures to combat addiction are currently insufficient in Japan, and further research on addiction is necessary. Methods Science Council of Japan (SCJ) has three subcommittees – the Addiction Subcommittee,...

Background: Alcohol problems in parents have been revealed to affect adolescent alcohol misuse. However, few studies examine the effects of parental drinking on adolescent risky drinking (including binge drinking) in the general population. In particular, previous study findings are inconsistent regarding the influence of parental drinking accordi...

Background There are a few studies on gender differences in terms of reasons and motives for methamphetamine use. Purpose/Objectives: To examine gender differences in triggers of methamphetamine use Methods: We provided a questionnaire survey to 699 inmates who were incarcerated because of violation of the Stimulants Control Act. Results: The resul...

Aim: The objective of the current study was to identify risk factors that affect the onset of dependence and chronic psychosis due to cannabis use. Methods: We examined clinical genetic factors, psychiatric disorders prior to cannabis use, starting age of cannabis use, duration and frequency of cannabis use, types of cannabis products used, comb...

BACKGROUND The effect of a web-based relapse prevention program might vary depending on a specific population if the study participants included drug users who had various characteristics. OBJECTIVE The aim of this secondary analysis was to explore subgroups that may receive benefits from a web-based relapse prevention program among Japanese drug...

Background: Internet-based intervention could help drug users recover from drug dependence. This study evaluated the effectiveness of a newly developed web-based relapse prevention program (e-SMARPP) for people with a drug problem, including the use of methamphetamine, in Japan. Methods: The study was a pilot randomized controlled trial comprise...

Background: Alcohol problems in parents have been revealed as one factor affecting adolescent alcohol misuse, but there are few studies on how parental drinking affects adolescent alcohol misuse in the general population. The findings of previous studies are inconsistent with respect to the influence of parental drinking according to parental struc...

Background: Alcohol problems in parents have been revealed to affect adolescent alcohol misuse. However, few studies examine the effects of parental drinking on adolescent risky drinking (including binge drinking) in the general population. In particular, previous study findings are inconsistent regarding the influence of parental drinking accordin...

Background: Alcohol problems in parents have been revealed to affect adolescent alcohol misuse. However, few studies examine the effects of parental drinking on adolescent risky drinking (including binge drinking) in the general population. In particular, previous study findings are inconsistent regarding the influence of parental drinking accordin...

Objectives Current clinical guidelines discourage long-term prescription of benzodiazepines and Z-drugs (BZD); however, the practice continues to exist. The aim of this study was to investigate the proportion of long-term BZD prescriptions and its risk factors. Design Retrospective cohort study using a health insurance database. Setting Japan. P...

Aims The use of new psychoactive substances (NPS) has become increasingly widespread over the last decade, in Japan and internationally. NPS are associated with a range of increasingly serious clinical, public, and social issues. Political measures to ameliorate the effects of NPS in Japan have focused on tightening regulation rather than establish...

Aims Pharmacotherapy for methamphetamine dependence has not yet been developed in Japan or elsewhere in the world. Ifenprodil is a blocker of G protein‐activated inwardly rectifying potassium channels that play a key role in the mechanism of action of addictive substances. Our aim is to examine the safety, efficacy, and outcomes of ifenprodil for t...

Aim This was an exploratory study to examine the factors influencing nursing home placement (NHP) in Japan. Methods For this analysis, 633 patients were selected. The data were collected from the clinical records of each patient. A log‐rank test was performed. The time from the patient's first visit to the clinic until the nursing home placement w...

1 Aims This study aimed to investigate the influence of tightened regulations on new psychoactive substances in patients with disorders related to these drugs in Japan. 2 Methods We used a biennial nationwide survey on drug‐related psychiatric disorders to examine why individuals who had previously used new psychoactive substances as their primary...

Background: The literature shows that computer-delivered interventions with personalized normative feedback can reduce problem drinking for up to 6 months in the West. Meanwhile, no studies have been conducted to examine the effects of such interventions among Japanese problem drinkers. Possible moderators associated with effectiveness of the inte...

This study explored the current implementation status of and opinions and concerns regarding suicide education at schools of social work in Japan. We conducted a survey of faculty members who taught at least one of the social work subjects. About half the respondents had given a lecture of some kind on suicide, and more than 80% agreed that suicide...

The purpose of this study was to investigate the sociodemographic characteristics of cancer patients who died by suicide in comparison with cancer-free cases. Suicide data from the Tokyo Medical Examiner's Office from 2009 to 2013 were extracted retrospectively. A total of 503 (5.1%) out of 9841 people who committed suicide had cancer; age ranged f...

This case-control psychological autopsy study explored suicide risk factors among Japanese individuals. We targeted 102 suicide completers over 20 years of age and 334 living controls matched to suicide cases by gender, age, and residential municipality in Japan. After controlling for other factors, we found significant associations between suicide...

Aim: Although the female suicide rate in Japan is one of the highest among OECD countries, little has been done to assess the psychosocial and psychiatric characteristics of Japanese female suicide completers. This study aimed to examine gender differences in psychosocial and psychiatric characteristics of suicide completers using a psychological...

The Serigaya Methamphetamine Relapse Prevention Program (SMARPP) cognitive behavioral therapy was implemented among 38 substance. abusers in 12-Step Program Treatment Centers operated by:the Drug Addiction Rehabilitation Center (DARC). Tochigi DARC members (20 patients) started SMARPP after attending daily programs in the treatment centers for an e...

Purpose: . In the last-decade, the treatment of drug offenders in Japanese prisons has changed from severe punishment to a therapeutic approach. This study aimed to review studies that evaluated the effectiveness of relapse prevention guidance for drug- dependent inmates in Japan. Methods: We searched three databases: Ichushi; the Japanese corre...

Aims: The aim of this study was to examine changes in the psychosocial backgrounds and clinical features of patients with psychiatric disorders associated with the new psychoactive substances (NPS) between 2012 and 2014 in Japan. Methods: Clinical features of patients with NPS-related disorders were compared using data from the Nationwide Mental...

Background Despite the effectiveness of psychosocial programs for recovery from drug use problems, there have been challenges in implementation of treatment. Internet-based and computerized approaches have been known to be effective in treatment dissemination. The study purpose is to assess the effects of a web-based psychosocial relapse prevention...

A cognitive behavioral therapy program entitled "STEM" was implemented with 42 drug dependent outpatients at Okayama Psychiatric Medical Center. Characteristics of 1 group who completed the program were examined, with the effectiveness of the program evaluated through monitoring longitudinal changes over a period of 8.5 months. Results showed that...

METHOD AND SUBJECTS: The sample was drawn from 231 outpatients diagnosed as DSM-IV substance use disorder, who had firstly consulted the drug dependence clinic of the Center Hospital, National Center of Neurology and Psychiatry between September 2009 and June 2013. Of the 231 potential subjects, 79 had participated in SMARPP at least once, and fina...

Background: Although drug abuse has been a serious public health concern, there have been problems with implementation of treatment for drug users in Japan because of poor accessibility to treatment, concerns about stigma and confidentiality, and costs. Therapeutic interventions using the Internet and computer technologies could improve this situa...

Drug overdose is a serious public health issue and fatal cases have been reported from various fields of medicine. This case-control analysis assessed the comparison between fatal overdose cases in the special wards of Tokyo Metropolitan area and prescribed psychotropic drugs in Tokyo in 2009-2010. It was suggested that the prescribed drugs serve a...

Objective: Assessing the degree of problems related to drug abuse is important in each treatment setting. The Drug Abuse Screening Test-20 (DAST-20) is a brief, simple 20-item instrument to measure the degree of problems related to drug use. The objective of the present study is to examine the reliability and validity of the Japanese version of th...

Background: Little is known about the use of multiple prescribers for benzodiazepines, which might reflect fragmented patient care and increases the risk of hospital admission for drug dependence or poisoning. Therefore, we aimed to identify the prevalence, prescribed quantities, and trajectory of multiple prescriber episodes for benzodiazepines....

Objective: In 2012, the Japanese Ministry of Health, Labour and Welfare implemented a policy to reduce the prescription of combined anxiolytic-hypnotic drug. In 2014, the policy was strengthened. To determine the effect of the anxiolytic-hypnotic polypharmacy reduction policy on the prescription of high-dose and combined anxiolytic-hypnotic drug in...

Positive therapeutic attitudes from healthcare professionals are important when providing medical services. The Drug and Drug Problems Perception Questionnaire (DDPPQ) measures healthcare professionals’ attitudes towards working with drug abusers. We developed a Japanese version (J-DDPPQ) and examined its reliability and validity among Japanese nur...

Little is known about psychotropic medication prescriptions prior to drug overdose. We aimed to examine the possible associations between the risk of overdose and exposures to various psychotropic medications. We conducted a matched case-control study of 3 groups of patients aged 12-74 years, using a large-scale health insurance claims database in...

Serigaya Methamphetamine Relapse Prevention Program (SMARPP) is an effective treatment program for drug-dependent patients that has been introduced by many psychiatric institutions. To conduct SMARPP effectively, the issues accompanying this program need to be clarified. Recently, an investigation was conducted on the healthcare/medical institution...

Over the past two decades, computerized and Internet-based interventions for the treatment of various health problems, including substance abuse, have been developed and used to resolve treatment-related issues. The purpose of this study is to review selected studies that conducted computerized and Internet-based psychosocial interventions for peop...

In Japan, few psychiatric institutions provide rehabilitation for drug dependence, since dependence on illicit drugs including methamphetamine has generally been regarded as a crime and not an illness by Japanese psychiatrists. However, partial revisions of the Penal Code (the Partial Stays of Execution System) are going to be enforced in 2016, and...

In this study, we compared the efficacy of a group relapse prevention program using the cognitive behavioral therapy-based workbook, Serigaya Methamphetamine Relapse Prevention Program (SMARPP), between patients abusing the so-called "dappou drugs" (designer drug in Japan, and those abusing methamphetamine (MAP). Both groups participated in the SMA...

The development of an effective treatment system for patients with addiction-related problems like substance abuse or pathological gambling is urgently needed. The purpose of this study was to clarify the therapeutic factors of the Tama Mental Health and Welfare Center Relapse Prevention Program (TAMARPP). The program is provided at the Tama Compre...

Suicide is a global public health problem and solutions to it can be found only through a global dialog. The suicide rate in Japan has been alarming, but Japan has made substantial efforts to reduce this rate, making prevention a high priority. This report reviews the developmental stages of a comprehensive policy of suicide prevention in Japan fro...

Introduction. Drug abuse in Japan began after World War II and has been characterized by three epidemics of methamphetamine abuse. During the third epidemic, drug abuse in Japan changed especially with an emergence of evasive drugs. These are manufactured, sold, and used at large and are not controlled by law, although they have psychotropic effect...

Introduction. Prescription drug abuse, including benzodiazepines, is a growing health problem in Japan. The Japanese government has expected community pharmacists to act as "gatekeepers" for prescription drug abusers. This study aimed to examine the pharmaceutical practices adopted by community pharmacists to prevent prescription drug abuse. Method...

Background. Web-based interventions for people with drug use problems are under-investigated. This study aimed to develop a new web-based relapse prevention (RP) program for people with drug use problems and to test its feasibility in Japan. Methods. A web-based program was developed based on an existing RP program. The program consisted of three m...

Background: Although drug abuse has been a serious public health concern, there have been problems with implementation of treatment for drug users in Japan because of poor accessibility to treatment, concerns about stigma and confidentiality, and costs. Therapeutic interventions using the Internet and computer technologies could improve this situat...

AimPrescription drug abuse, including benzodiazepines, is a growing health problem in Japan. This study examined the community pharmacist's clinical behavior regarding patients who overdose on prescribed drugs, and explore the possibility of overdose prevention by community pharmacists.Methods We surveyed all registered community pharmacies with di...

Objective This case-control psychological autopsy study aimed to explore a relationship between sleep disturbances and suicide among Japanese, as well as determine the importance and usability of screening for sleep disturbances in suicide prevention. Methods A semi-structured interview was conducted with the close family members of 49 adult suici...

We developed the TAMA mental health and welfare center Relapse Prevention Program (TAMARPP) and evaluated the efficacy of the program. We provided the program for 59 substance abusers at Tokyo Tama Comprehensive Mental Health and Welfare Center, and conducted brief interviews and questionnaire surveys to them four times during eight months follow-u...

Therapeutic attitudes of health care professionals toward people with substance abuse are predictors of better health care. This quasi-experimental study aimed to examine changes in therapeutic attitudes of health care professionals who offered the Serigaya Methamphetamine Relapse Prevention Program (SMARPP). The SMARPP was developed based on the M...

This study was designed to reveal the current status of the rehabilitation support system for patients with Illegal Substance Use Disorder (ISUD). From among 465 patients who had been admitted to a psychiatric hospital in Tokyo within the past 10 years by order of the prefectural governor, 65 patients with ISUD were selected for inclusion in this s...

The aim of this study was to clarify the clinical features of designer-drug-abusing patients through comparisons with methamphetamine-abusing patients and hypnotics/anxiolytics-abusing patients. Information on 126 designer-drug-abusing patients, 138 methamphetamine-abusing patients, and 87 hypnotics/anxiolytics-abusing patients was extracted from t...

Context: Despite evidence of an increase in the number of young patients receiving mental health treatment, most psychotropic medications have not been approved for the treatment of children and adolescents by the Ministry of Health, Labour and Welfare. There is little data available on psychotropic medication use in children and adolescents in Jap...

Objective: To assess spatial variability in psychotropic polypharmacy among recipients of public assistance. Design: We used pharmacy claims data from the 2011-2012 Fact-finding Survey on Medical Assistance conducted in Japan. Data were collected from all public assistance recipients who received outpatient treatment and obtained prescription medi...

Japan has experienced an epidemic of methamphetamine (MAP) abuse three times: the first epidemic was from 1951 to 1957, the second epidemic was from 1970 to 1994, and the third epidemic started in 1995 and continues today. Fortunately, HIV infection is not as serious a problem in Japan as it is in other countries. The major route of HIV infection i...

Although some studies about the prevalence of alcohol-related problems in general hospitals have been conducted in Japan, it may seem that some of Japanese physicians and surgeons appear to have less interest in alcohol-related problems. We investigated the prevalence of problematic drinking among outpatients visiting general hospitals in Tokyo, an...

The aim of this study was to evaluate the effect of a relapse-prevention program for methamphetamine (MAP)-dependent inmates in a prison. Participants were 251 male inmates with MAP-abuse problems. We compared scores on the Self-efficacy Scale for Drug Dependence (SSDD) and the Stages of Change Readiness and Treatment Eagerness Scale (SOCRATES) bef...