Skip to main content Accessibility help

A national survey of offending behaviour amongst intellectually disabled users of mental health services in Ireland

  • P. Leonard (a1), A. Morrison (a2), M. Delany-Warner (a3) and G. J Calvert (a4)



Offenders with an intellectual disability pose a major challenge to Intellectual Disability Service providers in the Republic of Ireland. This is especially so as no national Forensic Intellectual Disability Service currently exists.

The Forensic Intellectual Disability Working Group of the Irish College of Psychiatrists was established in order to take steps to address this issue by establishing the level of need for a Forensic Intellectual Disability Service in Ireland and developing a college position paper.

No previous study has been carried out to measure offending behaviour amongst persons with an intellectual disability attending mental health services in Ireland.


A postal survey was undertaken targeting the lead clinicians of all Intellectual Disability Psychiatry, General Adult Psychiatry and Forensic Psychiatry Services in the Republic of Ireland. This survey requested anonymous data regarding service users with an intellectual disability and offending behaviour in this population.


Data relating to 431 service users was returned. Those reported to engage in offending behaviour were predominantly young males. Assault was the most common offence type. A significant number of serious offences such as unlawful killing, sexual assault and arson were reported.


There is an urgent need for the development of a Forensic Intellectual Disability Service in the Republic of Ireland. The current efforts of the National Forensic Mental Health Service to establish such a service by the creation of a post of Consultant Forensic Psychiatrist (special interest in intellectual disability) are to be welcomed.


Corresponding author

*Address for correspondence: Dr P. Leonard, St Joseph’s Intellectual Disability Service, St Ita’s Hospital, Portrane, Co. Dublin, Ireland. (Email:


Hide All
Alexander, R, Hiremath, A, Chester, V, Green, F, Ganuratna, I, Hoare, S (2011). Evaluation of treatment outcomes from a medium secure unit for people with Intellectual Disability. Advances in Mental Health and Intellectual Disabilities 5, 2232.
American Psychiatric Association (1994). DSM-IV Diagnostic and Statistical Manual of Mental Disorders, 4th edn. American Psychiatric Pub Incorporated: Washington, DC.
Brown, B, Courtless, T (1968). The Mentally Retarded Offender. Publication number (HSM) 72, 19–39, Department of Health Education and Welfare. US Government Printing Office: Washington, DC.
Brown, B, Courtless, T (1971). The mentally retarded in penal and correctional institutions. American Journal of Psychiatry 124, 11641169.
Coid, JW (1988). Mentally abnormal prisoners on remand: 1 rejected or accepted by the NHS? British Medical Journal 296, 17791782.
Day, K (1993). Mental health services for people with mental retardation: a framework for the future. Journal of Intellectual Disability Research 37, 717.
Department of Health (1996). Discussion Document on the Mental Health Needs of Persons with Mental Handicap. Department of Health: Dublin.
Department of Health and Children (2006). A Vision for Change. Report the Expert Group on Mental Health Policy. Department of Health and Children, Dublin, Ireland.
Emerson, E (1995). Challenging Behaviour: Analysis and Intervention in People with Learning Disabilities. Cambridge University Press: Cambridge, UK.
Fazel, S, Xenitidis, K, Powell, J (2008). The prevalence of intellectual disabilities among 12,000 prisoners – a systematic review. International Journal of Law and Psychiatry 31, 369373.
Gudjonnson, GH, Clare, ICH, Rutter, S, Pearse, J (1993). Persons at Risk during Interviews in Police Custody: The Identification of Vulnerabilities. HMSO: London.
Gunn, J, Maiden, T, Swintion, M (1990). Mentally Disordered Prisoners. Home Office: London.
Hayes, S (1993). People with an Intellectual Disability and the Criminal Justice System: Appearances before Local Courts: Sydney. Law Reform Commission: NSW.
Hayes, S (1996). People with an Intellectual Disability and the Criminal Justice System: Two Rural Courts: Sydney. Law Reform Commission: NSW.
Health Research Board (2006). Annual Report the National Intellectual Disability Database Committee 2006. Health Research Board, Dublin, Ireland.
Hodgins, S (1992). Mental disorder, intellectual deficiency, and crime – evidence from a birth cohort. Archives of General Psychiatry 49, 476483.
Holland, T, Clare, I, Mukhopadhyay, T (2002). Prevalence of ‘criminal offending’ by men and women with intellectual disability and the characteristics of ‘offenders’: implications for research and service development. Journal of Intellectual Disability Research 46 (Suppl. 1): 620.
Irish College of Psychiatrists (2007). People with Learning Disability who Offend: Forgiven but Forgotten?, Occasional Paper No. 63 (OP63), Royal College of Psychiatrists, Dublin, Ireland.
Irish Statute Book (2006). Criminal Law (Insanity) Act 2006, Government Publications, Dublin, Ireland.
Irish Statute Book (2013). Assisted Decision Making (Capacity) Bill 2013, Government Publications, Dublin, Ireland.
Leonard, P, Hillery, J, Staines, M (2007). The challenge of applying mental health law reform to the intellectual disability sector in Ireland. Irish Journal of Psychological Medicine 24, 4749.
Leonard, P, McLaughlin, M (2009). Capacity legislation for Ireland: filling the legislative gaps. Irish Journal of Psychological Medicine 26, 165168.
Lindsay, WR (2002). Research and literature on sex offenders with Intellectual and developmental disabilities. Journal of Intellectual Disability Research 46, 7485.
Lyall, I, Holland, A, Collins, S (1995). Offending by adults with learning disabilities and the attitudes of staff to offending behaviour: implications for service development. Journal of Intellectual Disability Research 39, 501508.
McCord, W, McCord, J (1959). Origins of Crime: A New Evaluation of the Cambridge-Somerville Youth Study. Colombia University Press: New York, NY.
Moffit, TE, Gabrielli, WF, Mednick, SA, Schulsinger, F (1991). Socio-economic status, IQ and delinquency. Journal of Abnormal Psychology 90, 152157.
Murphy, G, Hartnett, H, Holland, A (1995). A survey of Intellectual Disabilities amongst men on remand in prison. Mental Handicap Research 8, 9198.
Murphy, M, Harrold, M, Carey, S (2000). A Survey of the Level of Learning Disability amongst the PRISON Population in Ireland. Report the Department of Justice, Equality and Law Reform, Dublin, Ireland.
Myers, F (2004). On the Borderline? People with Learning Disabilities and/or Autism Spectrum Disorders in Secure, Forensic and other Specialist Settings. Scottish Development Centre for Mental Health, Edinburgh, Scotland.
National Crime Council of Ireland (2006). National Crime Council Statistics (, accessed on 28 March 2013.
National Disability Authority Ireland (2003). Review of Access to Mental Health Services for People with Intellectual Disabilities. National Disability Authority Ireland, Dublin, Ireland.
O’Brien, G (2002). Dual diagnosis in offenders with intellectual disability: setting research priorities: a review of research findings concerning psychiatric disorder (excluding personality disorder). Journal of Intellectual Disability Research 46, 2130.
O’Neill, C (2006). Liaison between criminal justice and psychiatric systems: diversion services. Irish Journal of Psychological Medicine 23, 8788.
Royal College of Psychiatrists (2012). Safe Patients and High Quality Services: A Guide to Job Descriptions and Job Plans for Consultant Psychiatrists. Royal College of Psychiatrists, London, UK.
Simons, RL (1978). The meaning of the IQ delinquency relationship. American Sociological Review 43, 268270.
Simpson, M, Hogg, J (2001 a). Patterns of offending among people with Intellectual Disability: a systematic review. Part 1: methodology and prevalence data. Journal of Intellectual Disability Research 44, 384396.
Simpson, M, Hogg, J (2001 b). Patterns of offending among people with Intellectual Disability: a systematic review. Part 2: predisposing factors. Journal of Intellectual Disability Research 44, 397406.
Thompson, HJ, Roberts, RN, Whiddon, MF (1979). Inadequacy of brief IQ measures in the classification of mentally retarded prisoners. American Journal of Mental Deficiency 83, 416417.
West, DJ, Farrington, DP (1973). Who Becomes Delinquent? Heinemann: London.
Winter, N, Holland, AJ, Collins, S (1997). Factors predisposing to suspected offending in adults with self reported learning disabilities. Psychological Medicine 27, 595607.
World Health Organisation (1992). The ICD-10 Classification of Mental and Behavioural Disorders. WHO: Geneva.
Xenitidis, K, Russell, A, Murphy, D (2000). Management of people with challenging behaviour. Advances in Psychiatric Treatment 7, 109115.



Altmetric attention score

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed