News Release 

Treatment for sexual and domestic violence offenders does work

University of Kent

A first-of-its-kind study has found that specialised psychological programmes for sexual and domestic violence offenders have led to major reductions in reoffending but best results are achieved with consistent input from a qualified psychologist.

For the study, which was led by Professor Theresa Gannon at the University of Kent, a team of psychologists from the UK and Canada reviewed 70 previous studies and 55,000 individual offenders from five countries (UK, Canada, USA, Australia, New Zealand) to examine whether specialised psychological offence treatments were associated with reductions in recidivism.

Three specialised treatments were examined: sexual offence, domestic violence and general violence programmes, with the first two comprising the majority of specialised psychological programmes offered in correctional and community settings.

The study showed that, across all programmes, offence specific reoffending was 13.4% for treated individuals and 19.4% for untreated comparisons over an average follow up of 66?months. Relative reductions in offence specific reoffending were 32.6% for sexual offence programmes, 36% for domestic violence programmes, and 24.3% for general violence programmes. All programmes were also associated with significant reductions in non-offence specific reoffending.

However, overall, treatment effectiveness appeared improved when programmes received consistent hands-on input from a qualified registered psychologist and facilitating staff were provided with clinical supervision. For sexual offenders, specific group-based treatment, rather than mixed group and individual treatment, produced the greatest reductions in sexual reoffending as did treatment that focussed specifically on reducing inappropriate sexual arousal. All sexual offence treatment in these studies was Cognitive Behavioural Therapy.

Amongst its recommendations, the study suggests that policy makers and offender programme providers might optimise programmes outcomes by providing qualified psychologists who are consistently present in hands-on treatment. It also suggests that programme providers might also want to consider methods for tightly controlling programme implementation given that the researchers found single site treatments seemed to fare better than multisite treatments.

Professor Gannon, a chartered forensic psychologist and Director of Kent's Centre of Research and Education in Forensic Psychology, said: 'The results of this study are good news. They suggest that treatment can be effective; particularly if care and attention is paid to who delivers the treatment as well as how treatment is implemented.'


The study, entitled 'Does specialized psychological treatment for offending reduce recidivism? A meta-analysis examining staff and program variables as predictors of treatment effectiveness' (Theresa A. Gannon, University of Kent; Mark E. Olver, University of Saskatchewan; Jaimee S. Mallion, Kent; Mark James, Kent), is published in Clinical Psychology Review.

For further information and interview requests with Professor Theresa Gannon please contact the Press Office at the University of Kent.

Tel: 01227 823985


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Notes to Editors

Established in 1965, the University of Kent - the UK's European university - now has almost 20,000 students across campuses or study centres at Canterbury, Medway, Tonbridge, Brussels, Paris, Athens and Rome.

In June 2017 it was awarded a gold rating, the highest, in the UK Government's Teaching Excellence Framework (TEF).

In 2018 it was also ranked in the top 500 of Shanghai Ranking's Academic Ranking of World Universities and 47th in the Times Higher Education's (THE) new European Teaching Rankings.

Kent is ranked 17th in the UK for research intensity (REF 2014). It has world-leading research in all subjects and 97% of its research is deemed by the REF to be of international quality.

Along with the universities of East Anglia and Essex, Kent is a member of the Eastern Arc Research Consortium (

The University is worth £0.7 billion to the economy of the south east and supports more than 7,800 jobs in the region. Student off-campus spend contributes £293.3m and 2,532 full-time-equivalent jobs to those totals.

Kent has received two Queen's Anniversary prizes for Higher and Further Education.

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