Illicit drug use is a significant problem worldwide, often addressed in the global north through advanced medicalization, harm reduction, and communitarian approaches. Despite illicit drug use in Japan declining since the mid-1990s, Japan has deepened surveillance and expanded incarceration. Once leading the world market in methamphetamine use per capita, Japan's war on methamphetamine devastated user communities and marginalized psychiatrists by excluding them from hospitals and academic institutions. Since 2005, however, psychiatrists specializing in addiction have publicly revolted against Japan's war on drugs. Their activities were legitimized but also circumscribed by the world's largest organization for citizen research and non-governmental addiction rehabilitation, the Drug Addiction Rehabilitation Centers (DARC), that expanded in every prefecture since its inauguration in 1985. Drawing on two years of ethnographic fieldwork with psychiatrists, clinicians, welfare specialists, citizen researchers, and people who use drugs (addiction tojisha) who became agonists, this dissertation investigates illicit drug use and the nature of psychological pathology from the generative perspective of psychiatric care that challenges normative investments into criminal and clinical states of addiction. I conducted this research in the National Center of Neurology and Psychiatry (NCNP) in Western Tokyo Prefecture, the harm reduction-informed psychiatric hospital I call 'Ruru clinic', and in a variety of non-clinical places such as DARCs, courts, and prisons. I analyze psychiatric care as a socially transformative — rather than pathologizing and silencing — set of practices that produce novel imaginaries concerning harm, care, and the social life of mental health. My interlocutors made extraordinary efforts to render the non-specific somatic signs of distress, which I call exhausted life, into a therapeutic object and a habitable identity. I examine how the body and its illnesses are being shaped by multiple, often incommensurate, discourses on the material manifestations of harm, inflicted by drug use and incarceration. My work intervenes into pressing global social health issues by documenting the multiplicity of standpoints through which diagnostics, research, and therapeutics of addiction shape public concepts and criminal processes. By exploring the medico-legal underpinnings of mental health, I introduce critical theoretical perspectives on punishment, subjectivity, medicine and morality, affects and emotions, and the politics of impairment.