Potential Risk Factors for Methamphetamine Use Among Inmates in a Japanese Prison

Background: In Japan, drug addiction recovery guidance and social reintegration programs are implemented for eligible inmates in many prisons. However, methamphetamine addiction, especially among those with a history of thinner inhalation, often seems not to be adequately addressed in addiction treatment programs. The comorbidities of substance use disorders may be generally overlooked. This study aimed to provide valuable data for guiding the development of programs to combat drug addiction and support social reintegration for inmates. The first step of this study sought to determine the association between history of daily/regular methamphetamine use and use of other substances as well as the relationship between methamphetamine use and sociodemographic background. Methods: This retrospective study included 470 consecutive inmates whose data were obtained andwho consulted a certified psychiatrist. Chi-square tests and paired t-tests were used for the analysis. Furthermore, a multinominal regression analysis was performed. Results: Our findings revealed that the history of daily/regular methamphetamine use was significantly associated with the history of psychiatric consultation, sexually transmitted infections, daily/regular thinner inhalation, and daily/regularly tobacco smoking. Moreover, daily/regular thinner inhalation was initiated at a significantly younger age than methamphetamine use. In addition, tobacco smoking was initiated at a significantly younger age than methamphetamine use. Conclusion: The present study suggested that a history of daily/regular thinner inhalation and daily/regular tobacco smoking may serve as potential risk factors for the development of daily/regular methamphetamine use. These results may provide valuable insights for supporting and protecting inmates with methamphetamine addiction as well as individuals at risk. Trial registration: Not applicable.