When health care practitioners provide care, they emphasize a holistic approach [1], and sexuality is an integral part of that care [2]. The World Health Organization (WHO) [3] defines sexuality as “a central aspect of being human throughout life is sexuality, which encompasses sex, gender identities and roles, sexual orientation, eroticism, pleasure, intimacy, and reproduction.” Literature reviews have revealed that health care practitioners receive limited education on sexuality and would benefit from additional training [4,5].

The guidelines for comprehensive sexuality education, issued by the United Nations Educational, Scientific and Cultural Organization (UNESCO) in its International Technical Guidance on Sexuality Education: An Evidence-Informed Approach [6,7], have become the global standard. Comprehensive sexuality education has been implemented in many countries, primarily for adolescents [8-10].

In Japan, sexuality has long been a taboo topic [11]. After the first patient with AIDS was identified in 1985, an AIDS panic ensued, and sexuality education became widespread [12]. In 2002, a politician claimed that sexuality education was encouraging sexual activity, and sexuality education then declined sharply [12]. Sexuality education has lagged behind international standards for many years [13,14]. Only recently have school teachers worked on comprehensive sexuality education, including the development of teaching materials that reflect both the guidelines and the local cultural and social context [15]. Regarding sexual minorities, homosexuality has historically been regarded as an abnormal sexual desire. However, the term LGBT (lesbian, gay, bisexual, transgender/transsexual) has been widely used since the early 2010s, and public awareness has increased [16]. Nevertheless, a nationwide survey revealed that 11.3% of the general population did not understand the meanings of the questions about sexual minorities [17], indicating that understanding remains insufficient. Furthermore, 14% of people reported having negative feelings toward homosexual colleagues [17], indicating that acceptance of sexual minorities is still limited. Thus, in Japan, sexuality has been considered taboo and has not been adequately taught, and prejudice against sexual minorities still persists, leading to resistance to discussing sexuality [18].

Illness can affect sexuality, including in the context of mental illnesses [19,20]. Mental illness is a global public health challenge with a lifetime prevalence of 12% to 47.4% [21], with approximately half of individuals developing the illness by the age of 14 years [22]. Review studies on sexuality among people with various mental illnesses have shown high rates of unintended pregnancy, domestic violence, sexual dysfunction due to medication side effects, and divorce [19,23,24]. Furthermore, despite being sexually active, people with mental illness may experience psychological suffering, including sexual stigma, low sexual confidence, and unmet sexual desires [19,20,25,26].

However, sexuality is still largely ignored in mental health settings [27]. Mental health practitioners may avoid the topic because they see it as outside their scope of practice, give it low priority, or feel uncomfortable discussing it; similar barriers have been reported among health care practitioners more broadly [28,29]. Additional barriers in mental health care include concerns about worsening a client’s mental health condition and the view that sexuality is not part of recovery [30-33]. Recovery is now a central concept in mental health services and a key goal of rehabilitation [34], and romantic loneliness is associated with poor recovery [35]. Intimate relationships may therefore form part of recovery, and sexuality may be an important barrier to address [20]. In this study, sexuality is defined as an important part of building intimate relationships and as an essential element of recovery for people with mental illness.

For people with mental illness, 1 major problem is that practitioners rarely address sexuality [27]. In a survey of people with mental illness in Japan, 59% reported having no one to consult about sexuality, and among those who did, most turned to psychiatrists, friends, or family members, whereas only a few consulted psychologists, nurses, or social workers [36]. Health care practitioners often lack sufficient knowledge and appropriate attitudes regarding sexuality [18]. Mental health practitioners, therefore, need the knowledge, attitudes, and confidence required to provide counseling and comprehensive sexuality education as part of recovery-oriented care for people with mental illness.

Previous international studies have examined these barriers to addressing sexuality in mental health care [37]. These studies suggest that mental health practitioners lack knowledge and skills related to sexuality support [31] and require training to overcome these barriers [30]. However, there are few studies on the development of training about sexuality for people with mental illness, with only a small number of interventions focusing on training for mental health nurses [38,39], mainly for hospitalized patients rather than clients living in the community. Psychiatric hospitals are settings focused on crisis management, where sexuality support is reported to be less of a priority [40]. A systematic review also reports implicit norms that view inpatient sexual behavior as risky [41]. Institutions pose special challenges with patient sexuality, including physical space [27]. For these reasons, sexuality support in inpatient settings may differ substantially from sexuality support in community settings.

In Japan, policies have shifted from inpatient treatment to community care, and mental health practitioners increasingly support people with mental illness in community settings [42]. Community-based mental health practitioners include a wide range of professionals, such as nurses, social workers, occupational therapists, and others [43]. Because support related to sexuality is especially relevant to community settings [44], it is important that these practitioners are able to provide effective support. To our knowledge, however, no training program in Japan has been reported for mental health practitioners who support the sexuality of people with mental illness.

Against this background, we developed a support training program (RIKASEKU-SAPOPRO) through coproduction among peers with mental illness, researchers, and mental health practitioners. The program was based on the International Technical Guidance on Sexuality Education: An Evidence-Informed Approach [7] and was designed to enable mental health practitioners to support the sexuality of people with mental illness living in the community. The outcome variables—knowledge, attitudes, and confidence in providing sexuality-related support—were selected based on an intervention study of a sexuality support training program for hospital mental health nurses [39]. This study uses a randomized controlled trial (RCT) to compare an intervention group that participates in the program with a control group that does not.

This study evaluates the effectiveness of a sexuality support training program by examining whether practitioners gain knowledge, improve attitudes, and build confidence in providing sexuality-related support to their clients with mental illnesses.

The study design is an RCT with a 2-arm parallel group comparison. Participants are randomly assigned to either the intervention or control group after the baseline assessment. Participants in the intervention group complete an online questionnaire at 3 points in time: baseline (T1), immediately after the program (T2), and 1 month after the program (T3). The control group receives no program during the study period and is also assessed 3 times (T1-T3). To ensure that all participants are given an opportunity to take part in the program, the control group is offered the program after the final assessment (T3) has been completed. This protocol was developed and is reported in accordance with the Standard Protocol Items: Recommendations for Interventional Trials (SPIRIT) 2013 checklist (Checklist 1).

This study was conducted in Japan. Participants were recruited through a dedicated research website and through information distributed to community-based institutions and networks that support people with mental illness.

The study participants are qualified practitioners aged 18 years or older who provide community-based support to people with mental illness. There are no restrictions on profession; eligible practitioners include physicians, nurses, social workers, psychologists, occupational therapists, and others. The certifying body of professional qualifications, such as a national or municipal authority, is not used as an eligibility criterion. Since the 21st century, Japan has experienced increased immigration, including labor immigration [45]. For this reason, no restrictions are placed on ethnicity, and ethnicity is collected as a demographic characteristic. The exclusion criteria are the inability to participate in the online survey or Zoom video conferencing and difficulty participating in group discussions in Japanese.

KN prepared an allocation list stratified by assigned sex at birth (female or male). In Japan, policy guidance has generally favored assigning practitioners of the same sex for care that service users may perceive as sensitive or embarrassing, partly to protect the rights and dignity of people with disabilities [49]. Practitioner sex may therefore influence the effectiveness of the program, as providing sexuality-related support to same-sex versus opposite-sex clients may affect the content and type of counseling offered. In addition, understanding of sexual diversity remains limited in some settings in Japan; even health care practitioners may encounter discrimination related to sexual minority status [36], and some individuals may be reluctant to disclose their gender identity even when distressed [50]. These sociocultural factors influenced the study design and informed the decision to avoid stratification based on gender identity. Randomization was therefore stratified by sex assigned at birth in order to reduce the privacy burden associated with collecting sensitive personal information.

The allocation is performed using REDCap (Research Electronic Data Capture; Vanderbilt University), a widely used web application for building and managing online surveys and databases. KN prepared the allocation list before enrollment began. REDCap locks the randomization model to ensure that it is not modified once a study becomes active. After M Kageyama confirms that participants have responded to the online survey (T1), M Kageyama enters the assigned sex at birth data into REDCap, and random allocation is performed automatically. M Kageyama communicates the allocation results displayed in REDCap to participants by email. Group assignment is unknown to researchers other than M Kageyama. M Kageyama is the sole individual with access to the test dataset, which is managed through REDCap. M Kageyama is responsible for extracting group information from the final dataset and subsequently providing the dataset to M Kusaka for statistical analysis.

We plan to recruit 76 participants. A previous study [51] conducted a similar intervention; in that study, the average scale score of the primary outcome variable before the training was 23.39, and the average scores 1 week and 3 months later were both 18.56. In our study, we assume that the intervention group’s average score 1 month after the intervention will be 18.56, compared with 23.39 for the control group. Furthermore, the previous study [51] that examined the validity of the scale reported an average of 19.5 (SD 5.5). In our study, taking into account the intervention and the characteristics of the participants, the SD is assumed to be 6.5.

Under the above assumptions, if a 2-tailed t test is used with an α error of 5% on both sides and a power of 80%, the required sample size is 60 (n=30 for each group). After considering a dropout rate of 20%, the required sample size is 76. The study’s intervention is administered on a group-by-group basis; however, given the nature of the intervention, the expected small group effect allows for a sample size calculation method that presumes independence.

Procedures for recruitment, eligibility determination, and enrollment are presented in Textbox 1

Knowledge of sexuality education is a secondary outcome. The items test knowledge about the content of the textbook “Mana Book” and include items such as “Outing is talking about things that pertain to your privacy that you have not shared before” [15]. The test consists of 30 items with “Correct,” “Wrong,” and “Don’t know” options. Scores are totaled, with 1 point awarded for each correct answer. Total scores range from 0 to 30.

Knowledge regarding preconception care for people with mental illness is a secondary outcome. The items are based on perinatal clinical practice guidelines for women with mental illness published by academic societies [54]. The 5 items, such as “It is desirable for mental illness to be stable for at least 3 months before becoming pregnant” and “Most psychotropic medications are compatible with breastfeeding,” have been used in a survey [36]. Responses are “I knew” and “I didn’t know.” The scores (1 point for “I knew”) are totaled. Scores range from 0 to 5.

The process assessment is conducted only on the intervention group. It includes questions about satisfaction (multiple choice and free text), whether the program would be useful for future support (multiple choice and free text), whether they would recommend the program to other practitioners (multiple choice and free text), and what changes occurred (free text). How the support was reflected during the 1-month follow-up period will be shown through an analysis of the qualitative data obtained from “What changes occurred (free text).”

Demographic variables are collected during the baseline assessment (T1). Outcome variables are collected during the baseline assessment (T1), assessment 1 (T2), and assessment 2 (T3). A process assessment is conducted at T3 only for the intervention group. Table 2 shows the contents of the questionnaire.

The hypotheses of this study are (1) the intervention group will have higher confidence in providing sexuality-related support at T3 than the control group (hypothesis 1), (2) changes in confidence in providing sexuality-related support scores from T1 to T2 and T3 will be greater in the intervention group than in the control group (hypothesis 2), (3) scores on the Attitudes Toward Sexuality Scale at T3 will be higher in the intervention group than in the control group (hypothesis 3), (4) changes in the scores on the Attitudes Toward Sexuality Scale from T1 to T2 and T3 will be greater in the intervention group than in the control group (hypothesis 4), (5) scores for knowledge of sexuality education at T2 and T3 will be higher in the intervention group than in the control group (hypothesis 5), and (6) scores for knowledge regarding preconception care for people with mental illness at T2 and T3 will be higher in the intervention group than in the control group (hypothesis 6).

Data monitoring is performed by M Kageyama using REDCap. Because REDCap is used to collect questionnaire data, the date and time of questionnaire responses from T1 to T3 can be ascertained. The system is set up so that reminders to respond to the questionnaires are sent automatically 3 times at 2-day intervals. Participants are monitored to determine whether they complete the questionnaires within the 1-week time frame. If they do not respond by the deadline, they are contacted by email and then by phone if they do not respond to the email. If participants wish to withdraw from the study or do not respond to the questionnaires, M Kageyama will ascertain the reason by email or phone. The audit organization at the University of Osaka Hospital, which is independent of the researchers, conducts the audit at the end of the first case of intervention.

This study protocol has been evaluated and approved by the ethical review board at the University of Osaka Hospital (25040; 2025/6/18). Any future modifications to the protocol, should they arise, will be reviewed by the same ethical review board.

Written informed consent will be obtained from all participants. Study documents address ethical issues, including the study protocol, the voluntary nature of participation, the privacy policy, data management procedures, participant safety, and the absence of conflicts of interest. Study participants’ personal information is collected by M Kageyama via email, entered into a Microsoft Excel sheet, and password-protected for secure management before, during, and after the trial. After enrollment, if participants themselves declare their intention to withdraw, the intervention will be discontinued. At the end of the study, participants will receive a gift card worth JPY 3000 (approximately US $20) as a gesture of gratitude. The trial was registered with the UMIN Clinical Trials Registry (UMIN000058204; June 18, 2025).

After completing this study, we will publish the results in an international peer-reviewed medical or nursing journal and present the results at national and international conferences. Information on publication will be announced on the research home page in accordance with the journal’s publication rules. Authorship will follow the guidelines of the International Committee of Medical Journal Editors [55].

This training program is designed to enable practitioners to provide support regarding sexuality, with confidence in providing sexuality-related support as the primary outcome. A survey of people with mental illness in Japan revealed that they do not adequately use contraception or take measures against sexually transmitted diseases, and they lack the necessary knowledge before becoming pregnant [36]. Therefore, practitioners are required to provide sexuality education in a way that is tailored to each individual. The same survey also found that 18.3% of respondents with mental illness were sexual minorities [36], making it essential for practitioners who support people with mental illnesses to have a liberal attitude that accepts sexual diversity. If this study shows that practitioners in the intervention group have more knowledge about sexuality, a more liberal attitude, and greater confidence than those in the control group, it will provide evidence on the effectiveness of a coproduced sexuality support training program for practitioners working in community settings.

Two training programs for mental health practitioners regarding sexuality have been reported previously. One program is an 8-hour sexual health training program for mental health nurses in Taiwan [39], and the other is a 40-minute training program for mental health nurses in Australia [38]. The Taiwanese program covers a wide range of sexuality-related topics and includes not only lectures but also role-playing and discussions. This program improved knowledge, attitudes, and self-efficacy [39]. Compared with our program, it differs in that it targets mental health nurses working in hospitals, lasts 8 hours, and was evaluated using a quasi-experimental design. The Australian program focused more on counseling methods than on providing knowledge, and participants were evaluated through interviews to determine whether they were able to use the methods they learned in practice [38]. Compared with our program, it differs in that it targets mental health nurses, provides more advanced training, has a shorter training time, and uses interview-based rather than quantitative evaluation. Both programs are delivered by practitioners or researchers and are not facilitated by practitioner-peer facilitator pairs.

The main strengths of this program are that it targets a variety of community-based practitioners, includes peer facilitators, and evaluates effectiveness through an RCT. In accordance with the emphasis on coproduction [34], implementing this collaborative program between practitioners and peers holds considerable importance. In Japan, training facilitators for practitioners are usually researchers or practitioners, and people with mental illness rarely serve as facilitators [56]. Therefore, for many participants, it will be their first experience attending a training session facilitated by a person with mental illness. We hope that by incorporating the perspectives of people with mental illness, practitioners will gain new insights into their experiences and adopt a more flexible attitude.

In Japan, there is no program for learning how to provide sexuality support specific to mental illness. If this program proves effective, mental health practitioners in Japan may enroll in it. If practitioners who complete the program are able to provide sexuality support to people with mental illness, it may help improve their long-term well-being.

Several limitations should also be noted. First, recruitment may not be easy. A review article [32] reported that mental health practitioners consider sexuality a taboo subject and not of high interest unless it is directly related to their work. Despite publishing articles in mental health magazines about the need for sexuality support and raising awareness to ensure that the topic does not remain taboo, we may need to recruit participants proactively. Second, the outcomes focus on practitioners’ knowledge, attitudes, and confidence rather than direct client-reported outcomes because participants may not have opportunities to provide sexuality support within the 1-month follow-up period. Third, randomization is stratified by assigned sex at birth rather than gender identity, reflecting privacy considerations in the Japanese context; this decision should be interpreted within that context.

Given the substantial impact of culture and society on sexuality, it is imperative to develop health care practitioner training curricula tailored to each nation [7]. Continued program development should value coproduction with people with mental illness [34]. Future research may involve extending the follow-up period to design studies that more effectively measure the impact of the program in practice. Furthermore, future work should examine how coproduced programs can be implemented more widely and disseminated across community mental health settings.