Up to 70% of prisoners suffer from personality disorders

Treatment can be effective but is highly resource-intensive, says psychologist

Up to 70 per cent of prisoners suffer from personality disorders, about six times the rate in the general population, according to a senior Irish Prison Service psychologist.

Such disorders, which range from the mild to the highly disruptive, were long believed to be untreatable and simply part of offenders’ personalities.

However, according to the prison service’s senior psychologist, Dr Margaret McGovern, several promising treatments are now available to offenders in prison.

Common personality disorders in the prison system include emotionally unstable disorder (sometimes called borderline personality disorder) and dissocial personality disorder (sometimes known as antisocial personality disorder).


One of the better-known forms is psychopathy. However, this has always been a controversial diagnosis and is rarely applied, even in prisons, said Dr McGovern.

“Antisocial/dissocial personality disorder is much more commonly given in forensic settings,” she said.

Personality disorders differ from mental illness in that they are more persistent and, in the past, were seen as more intrinsic to the patient’s personality. Under the Mental Health Act 2001, which is currently under review, people with personality disorders are not considered to have a mental illness in the legal sense and cannot be involuntary detained in a secure institution such as the Central Mental Hospital.

Furthermore, a personality disorder diagnosis cannot be used as an insanity defence in a criminal trial. Personality disorders are “enduring behaviour patterns”, Dr McGovern said.

“What we find is that [sufferers] have inflexible responses to a wide range of personal and social situations.

“These behaviours can represent very extreme or significant deviations from the way the average individual would act.”

Huge difference

Some 60-70 per cent of prisoners have a personality disorder, she said. The figure for the general population is 4-11 per cent. “It’s a huge difference.”

The diagnosis is frequently mentioned in court cases, ranging from minor assaults or drug offences to high-profile murders and rapes.

A man who murdered two elderly brothers with special needs was described during his 2019 appeal as having been diagnosed with two personality disorders. Another man who set fire to an apartment with three children inside was described by his defence barrister as displaying traits of schizoid personality disorder.

The view that personality disorders are untreatable started to be challenged in the 1990s, leading to the development of several treatments, which have been specially adapted to prison settings, said Dr McGovern.

These include dialectical behavioural therapy (DBT), schema-focused therapy, mentalisation-based therapy and structured clinical management.

The tools learned in therapy sessions have been shown to “sustain people in a more stable way” once they are released from prison and to draw them away from criminal behaviour, she said.

However, these interventions are “very resource intensive” compared with standard therapies, said Dr McGovern.

They require a team of trained professions who have a high level of regular access to the patient. They often involve group and one-on-one therapy running concurrently and they can take up to three years to show any benefits. “There’s no quick fix with this,” the doctor said. The nature of the work means staff “burnout” can also be a problem.

Conor Gallagher

Conor Gallagher

Conor Gallagher is Crime Correspondent of The Irish Times