Ten years ago, the World Health Organization warned that prisons would become 21st century asylums. Now, that warning is becoming a reality.

Mental illness and substance use problems are more common among people in prison than in the community, and the number of people with these problems in prison is increasing over time. This is further complicated by the fact that between one-fifth and half of people in prison experience both mental illness and substance use problems at the same time. This is called 'dual diagnosis'.

But it's as these vulnerable people transition out of prison and back into the community that the harsh reality of these problems become clear.

For the first time globally, our research published in The Lancet examined the relationship between mental illness, substance use problems, and dual diagnosis in people recently released from prison.

ADDING UP THE COST OF INJURY

In order to understand the challenges that people with mental health problems face after release from prison, it's important to factor in injury. Injury is one of the major causes of death and disability globally; it can often result in hospitalisation which can, in turn, be very costly to society. Currently, it's estimated to cost over A$4 billion in direct healthcare every year in Australia. On average, each day spent in a hospital bed costs A$1840.

We know that people with mental illness or substance use problems are more likely to experience injury in the community than people without these problems. However, we know very little about injuries experienced by people released from prison, or how mental illness, substance use problems, and their co-occurrence may shape patterns of injury at a critical time for successfully reintegrating into society.

To understand this relationship, we identified injuries in emergency department and hospital records for 1307 people released from prisons in Queensland.

We found that people released from prison were at high risk of injury.

Adults with a dual diagnosis have a rate of injury three times higher than those released from prison with no mental health problems, and a rate of hospital admission over 12 times higher than among all adults in the community. For this group, the rate in the first 30 days after release from prison would be the same as experiencing an injury resulting in hospital contact every five months on average.

Although rates of injury have been steadily decreasing in the Australian community, people who have experienced incarceration, especially those with mental health problems, have not benefitted from efforts to reduce injuries to the same extent as the general population.

MISSING A HEALTH OPPORTUNITY

The number of people in prison in Australia has increased by 38% over the past five years. In 2017 alone, there were almost 64,000 releases from prison in Australia.

For the first time, we have shown specific groups and time periods where the risk of injury is greatest after release from prison. This important information can be used to direct scarce resources to those at greatest risk, and in time periods when this risk is at its greatest.

We found that most drug-related injuries (often recorded as poisoning or overdose) occurred within 30 days of release from prison, and people released from prison with dual diagnosis accounted for eight out of ten drug-related injuries during this time.

These findings indicate that targeting overdose prevention efforts to people with dual diagnosis within 30 days of release from prison has the potential to address many of these drug-related injuries.

However, drug-related injuries only account for one out of ten injuries over the 18-month study, including among those with a recent history of dual diagnosis. This is problematic because there are few interventions that target injury from causes other than substance use for people transitioning from prison to the community.

Overall, our findings indicate that some of the most vulnerable people released from prison experience an extremely high burden of injury in the community. The prevention of injury among people released from prison, particularly those with co-occurring mental illness and substance use problems, will likely reduce healthcare costs and should be a public health priority.

THE BURDEN OF RELEASE

Health typically improves while people are in prison in Australia. However, once people are released, their health often deteriorates so much that the overall effect of incarceration is health depleting. Adults released from prison with mental illness or substance use problems are at particularly high risk of poor health outcomes.

Hospitalisation, suicide attempts, and premature death soon after release from prison are far too common among people with these problems.

The key here is managing the transition from prison to the community which is an opportunity to not only prevent death, but actually improve the health of this highly vulnerable group in society.

We know that care which is coordinated and continuous improves health outcomes for people released from prison. However, in most cases the care provided to these people is neither continuous nor coordinated. Currently, this represents a public health opportunity missed.

Compared to people who have one mental health problem alone, people with dual diagnosis have increased health needs. But, specific services tailored to the needs of people with dual diagnosis are scarce in both prison and the community.

By coordinating mental health and addictions services without interruption when people transition from prison to community health providers is key to preventing injury in people released from prison.

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