About Us

BYDS is a longitudinal study of young people’s lives and experiences and is funded by the Research and Development Office, Public Health Agency, Northern Ireland.

By following the same young people over time, BYDS can identify the social, family and peer factors that can offer support and reduce young people’s participation in drug use and anti-social behaviour. By following participants longitudinally over the years, it is possible to make more meaningful inferences on the causes that may explain the emergence or decline of different patterns of behaviour. Other strengths of the study include the use of well-validated instruments and the wide range of constructs which have been investigated. The results from the study can be used to assist the future development of policy and practice (e.g. drug intervention programmes) and so provide greater opportunities for young people.

Just some examples of what we can answer:

• How do young people who are exposed to and try alcohol and drugs regulate internal impulses to use these substances?
• Does drinking while supervised by your parents at age 12 make you less likely to binge drink when you are older?
• How does exposure to violence affect mental health?
• How does parental control and peer pressure interact with deviant behaviour?

Aims & Objectives

The aim of the study is to investigate the risk and protective factors associated with different types of behavioural patterns and outcomes in adolescence through mid-adulthood. In particular, we are interested in factors affecting:

• The transition from secondary school into further education, employment and adult roles;
• The formation of romantic experience and attachment;
• Patterns of drug use and abuse across time;
• The effects of traumatic experiences in adolescence on adult wellbeing; and
• Pro-social and anti-social behaviour.

By collecting information about the different agents that may shape adolescents’ behaviours and outcomes over time (e.g. family, peers, school, neighbourhood), we hope to contribute in gaining a better understanding of the processes that influence behaviour in adolescence and their effects on adults. 

BYDS Method & Design

BYDS has followed a cohort of approximately 4000 young people from 2001 to 2010. Participants were from schools in Belfast, Ballymena and Downpatrick and were aged 11-12 upon entry to the study. Adolescents completed the survey on six occasions on a yearly basis from 2001-2005, then again in 2007 and 2010.

We are currently in our eighth sweep on data collection and the BYDS participants are now 34 years old.

During the school years, data were collected using pen and paper methods in school. For the 2025 survey, participants are being invited to complete the survey online or alternatively they can be interviewed in their home. The study is strictly confidential and participants cannot be identified in the publications. All participants have the right to withdraw from the study if they wish.

The questions which we have asked young people to answer may be grouped under the following headings:

• Substance use (drugs, alcohol, smoking; driving and substance use);
• Mental health (use of services, medication, self-harming and depression);
• Behavioural problems (anti-social behaviour, contact with criminal justice system, gang membership);
• Families (household composition, family processes, parental monitoring and attachment, running away, helping around the house, arguments with parents);
• Peers (social networks, relationships with peers, peer attachment, characteristics of school and non-school friends);
• Leisure activities (music and tv preferences, leisure activities, evenings out, disposable income);
• Neighbourhoods (attachment to neighbourhoods, community violence);
• Schools (behaviour in school, attitudes in school, educational aspirations, positive school behaviour, school performance, drugs education);
• Romantic and sexual relationships, marital status (pregnancies, children), STIs;
• Internet use;
• Employment and education (job, training, hours, income);
• Individual characteristics (e.g. psychological traits).

Study Results

Some of the publications associated with BYDS can be viewed here.