Initial findings from the Millennium Cohort Study Age 17 Sweep


Through the Millennium Cohort Study (MCS) we have been following the lives of over 19,500 people since they were born in the UK at the turn of the new century. Here you can read our initial findings from the Age 17 Sweep. These examine a range of issues, including mental health, obesity, substance use and antisocial behaviour.

Research details

Project title

Initial findings from the MCS Age 17 Sweep

Project lead

Emla Fitzsimons



Employment, income and wealth

Expectations, attitudes and beliefs

Family and social networks

Health behaviour

Housing and local environment

Mental health and wellbeing

Physical health




ESRC and a consortium of government departments


Using data from the most recent MCS sweep, at age 17, this project examined a range of issues relevant to young people’s lives today:

  • Mental ill-health
  • Overweight and obesity
  • Substance use and antisocial behaviour

Below you can read a summary of our briefings on each topic. You can also download and read the full briefings.

Mental ill-health

Key findings from this briefing include:

  • 16% of teenagers reported high levels of psychological distress at age 17.
  • 24% of young people reported self-harming and 7% reported self-harming with suicidal intent by age 17.
  • Females, White teenagers, those from disadvantaged backgrounds and sexual minority teens were all more likely to experience mental ill-health.

Overweight and obesity

Key findings from this briefing include:

  • 21% of cohort members were obese at age 17 and a further 14% were overweight, with rates remaining stable stable since age 14.
  • Rates of obesity were twice as high among teens from the poorest homes compared to those from the richest households (28% versus 14%).

Substance use and antisocial behaviour

Key findings from this  briefing include:

  • 31% of young people had tried cannabis and 10% had tried harder drugs by age 17.
  • 53% had engaged in binge drinking and 9% said they had done this on 10 or more occasions in the past year.
  • Prevalence of assault decreased from 32% at age 14 to 25% at age 17.




Briefings & Impact

Mental ill health in the UK at age 17 – Prevalence of and inequalities in psychological distress, self-harm and attempted suicide

Author: Praveetha Patalay and Emla Fitzsimons

This report focuses on mental ill-health at age 17, using data collected from participants in the Millennium Cohort Study (MCS) in 2018-19. It presents prevalence of psychological distress, self-harm and attempted suicide. It describes important mental health inequalities across the following key socio-demographic characteristics: sex, ethnicity, sexuality and socioeconomic position. Combined with data collected from a subset of participants during the COVID-19 national lockdown in May 2020, when they were aged 19, the report also presents evidence on changes in psychological distress from ages 17 to 19.

Briefings & Impact

Obesity prevalence and its inequality from childhood to adolescence – Initial findings from the Millennium Cohort Study Age 17 Survey

Author: Emla Fitzsimons and David Bann

This report focuses on excess weight at age 17 in the Millennium Cohort Study, presenting prevalence of obesity, overweight, normal weight and underweight. Examining also previous measures collected from the cohort since age 3, it highlights stark inequalities by family socioeconomic circumstances. It underlines the strong persistence of excess weight throughout childhood and adolescence, with one third of a whole generation either overweight or obese as they enter their prime adult years.

Briefings & Impact

Substance use and antisocial behaviour in adolescence – Evidence from the Millennium Cohort Study at age 17

Author: Emla Fitzsimons and Aase Villadsen

This report shows overall prevalences of engagement in risky behaviours, alongside breakdowns by sex, by parental educational level, and by UK country. In terms of sample characteristics, 50% were females, 36% had parents with a university degree or above, 13% were of ethnic minority origin, and the UK nations were represented by England (84%), Wales (5%), Scotland (8%) and Northern Ireland (3%). Analyses are adjusted for survey design and attrition, so figures are nationally representative estimates of risky behaviours among young people born in the UK around the turn of the millennium.


Featured scientific publications

Fitzsimons, E and Patalay, P
Psychological distress, self-harm and attempted suicide in UK 17-year olds: prevalence and sociodemographic inequalities
The British Journal of Psychiatry, 2021
Read the full paper

Relevant studies

Contact us

Centre for Longitudinal Studies
UCL Social Research Institute

20 Bedford Way
London WC1H 0AL


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