The Penrose Effect and its acceleration by the war on drugs: a crisis of untranslated neuroscience and untreated addiction and mental illness

In 1939, British psychiatrist Lionel Penrose described an inverse relationship between mental health treatment infrastructure and criminal incarcerations. This relationship, later termed the ‘Penrose Effect’, has proven remarkably predictive of modern trends which have manifested as reciprocal components, referred to as ‘deinstitutionalization’ and ‘mass incarceration’. In this review, we consider how a third dynamic—the criminalization of addiction via the ‘War on Drugs’, although unanticipated by Penrose, has likely amplified the Penrose Effect over the last 30 years, with devastating social, economic, and healthcare consequences. We discuss how synergy been the Penrose Effect and the War on Drugs has been mediated by, and reflects, a fundamental neurobiological connection between the brain diseases of mental illness and addiction. This neuroscience of dual diagnosis, also not anticipated by Penrose, is still not being adequately translated into improving clinical training, practice, or research, to treat patients across the mental illness-addictions comorbidity spectrum. This failure in translation, and the ongoing fragmentation and collapse of behavioral healthcare, has worsened the epidemic of untreated mental illness and addictions, while driving unsustainable government investment into mass incarceration and high-cost medical care that profits too exclusively on injuries and multi-organ diseases resulting from untreated addictions. Reversing the fragmentation and decline of behavioral healthcare with decisive action to co-integrate mental health and addiction training, care, and research—may be key to ending criminalization of mental illness and addiction, and refocusing the healthcare system on keeping the population healthy at the lowest possible cost.