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Andrew Percy

Photo of Andrew Percy

BSc (QUB); MSc (City, London); PhD (QUB).

Senior Lecturer in Criminology
Room: 1.04, 1 College Park
Ext: 5261 ; Email:

My main research interest is focused on teenage alcohol, drug use and crime. In particular, I am interested in why some young people use cigarettes, alcohol and drugs while others do not, and why for some young people substance misuse is a transient behaviour, but for others it develops into serious social, legal and health problems. My main work in this area has been the Belfast Youth Development Study (in collaboration with Dr Patrick McCrystal, Institute of Child Care Research). This is an ongoing longitudinal study of adolescent drug use and crime funded by the Research and Development Office (DHSS&PS). The BYDS has tracked the development of a sample of around 4,000 young people who were aged 11 in 2001. This work has been supplemented with a number of qualitative studies looking in more detail at specific teenage substance use behaviours.  I have also undertaken analysis of the major UK survey data sets including the British Cohort Study and the British Crime Survey.  

My second research interest is in methodological development in the areas of quantitative assessment of sensitive behaviours, measurement error in longitudinal survey research, and statistical methods for longitudinal data analysis. I am currently principle investigator on a European Research Advisory Board study attempting to further development growth mixture models for the analysis of longitudinal teenage alcohol data.

I have previously held research positions at the Institute of Child Care Research, the Home Office, and The Advisory Council on Alcohol and Drugs Education (TACADE)

Teaching interests

Youth crime and youth justice, basic and advanced statistics, victim surveys, secondary analysis of existing data, and research ethics.

Selected recent publications

Percy, A. Wilson, J., McCartan, C. & McCrystal, P. (2011). Teenage Drinking Cultures. York: Joseph Rowntree Foundation. [Full report] [Summary]

Percy, A. & Iwaniec, D. (2010). Teenage Drinking: Causes and Consequences. Saarbrucken: LAP Lambert Academic Publishing. [book]

McCrystal, P & Percy, A. (2010). Factors associated with teenage ecstasy use. Drugs: Education, Prevention, and Policy, 17, 507-527. [abstract]

McAloney, K., McCrystal, P., & Percy, A. (2010). Sex, drugs and STDs: Preliminary findings from the Belfast Youth Development Study. Drugs, Education Prevention and Policy, 17, 443-453. [abstract]

Cupples, M.E., Stewart, M.C., Percy, A., Hepper, P., Murphy, C.A., & Halliday, H.L., (2010).  A RCT of peer-mentoring for mothers in socially disadvantaged areas (The MOMENTS Study). Archives of Diseases in Childhood. [abstract]

McCrystal, P. & Percy, A. (2009). A profile of cocaine use in Northern Ireland. International Journal of Drug Policy, 20, 357-364. [abstract]

McAloney, K., McCrystal, P., Percy, A. & McCartan, C. (2009). Damaged youth: Prevalence of community violence exposure and implications for adolescent well-being in a post conflict society. Journal of Community Psychology, 37, 635-648. [abstract]

Percy, A., Thornton, M. & McCrystal, P. (2008). The extent and nature of family alcohol and drug use: Findings from the Belfast Youth Development Study. Child Abuse Review, 17, 371-386. [abstract]

Percy, A. (2008). Moderate adolescent drug use and the development of substance use self-regulation. International Journal of Behavioural Development, 32, 451-458. [abstract]

Percy, A. & Iwaniec, D. (2008). Antecedents of hazardous teenage drinking: Analysis of the 1970 British Cohort Study. CLS Working Paper Series 2008/6. London: Centre for Longitudinal Studies, Institute of Education. [Working paper 2008/6]

Murphy, C.A., Cupples, M.E., Percy, A., Halliday, H.L., Stewart, M.C. (2008).  Peer-mentoring for first-time mothers from areas of socio-economic disadvantage: A qualitative study within a randomised controlled trial. BMC Health Services Research, 8, 46 (27 February 2008). [BMC HSR paper]

Percy, A., McCrystal, P., & Higgins, K. (2008). Confirmatory factor analysis of the adolescent self-report Strengths and Difficulties Questionnaire. European Journal of Psychological Assessment, 24, 43-48. [abstract]

McCrystal, P., Percy, A., & Higgins, K (2007). School Exclusion Drug Use and Antisocial Behaviour at 15/16 years: Implications for Youth Transitions. Vulnerable Children and Youth Studies, 2, 181-190.

McCrystal, P., Percy, A., & Higgins, K (2007). Substance use behaviours of young people with a moderate learning disability: A Longitudinal Analysis.  American Journal of Drug and Alcohol Abuse, 33, 155-162

Percy, A. & Iwaniec, D. (2007). The validity of a latent class typology of adolescent drinking patterns. Irish Journal of Psychological Medicine, 24, 13-18. [IJPM Paper]

McCrystal, P., Higgins, K., & Percy, A., (2007).  Frequent cannabis use amongst aged 14/15 year olds in Northern Ireland.  Drug and Alcohol Dependence, 88, 19-27. [abstract]

McCrystal, P., Percy, A., & Higgins, K (2007).  Exclusion and marginalisation: the experience of school exclusion on drug use and antisocial behaviour.  Journal of Youth Studies, 10 (1), 35-54. [abstract]

McCrystal, P., Higgins, K., & Percy, A. (2007). The cost of drug use in adolescence: young people, money and substance abuse. Drugs: Education Policy and Prevention, 14,1 19-28.

McCrystal, P., Higgins, K., & Percy, A. (2006). School exclusion, drug use and delinquency in adolescence.  Journal of Adolescence, 29, 829-836.

McCrystal, P., Percy, A., & Higgins, K (2006).  Drug use patterns and behaviours of young people at an increased risk of drug abuse during adolescence. International Journal of Drug Policy, 17, 393-401.

Percy, A., McAlister, S., Higgins, K., McCrystal, P. & Thornton, M. (2005) Response consistency in adolescent drug use self-reports, Addiction, 100, 189-196. [abstract]