National Clinical Assessment and Treatment Service (NCATS) Treating young high risk harmful sexual behaviour

Serious sexual abuse by children and young people is one of the most high-risk issues we work with. Children and young people who develop harmful sexual behavior harm themselves and others.

Woman speakingNational Clinical Assessment and Treatment Service (NCATS) is a national service and offers assessment, treatment, consultation and training. We run NCATS in partnership with Oxleas NHS Foundation Trust.

Why children develop harmful sexual behaviour 

Children and young people who develop harmful sexual behaviour have usually experienced abuse and neglect themselves (Hackett et al, 2013; Hawkes 2009; McCartan et al, 2011).

A study by Hackett et al (2013) of children and young people with harmful sexual behaviour suggests that two-thirds had experienced some kind of abuse or trauma such as physical abuse, emotional abuse, sexual abuse, severe neglect, parental rejection, family breakdown, domestic violence, and parental drug and alcohol abuse. Around half of them had experienced sexual abuse.

illustration of umbrella

Around a third of sexual abuse is committed by other children and young people

Explanation: Research and crime statistics suggest that anywhere from one-fifth to two-thirds of sexual abuse is committed by other children and young people. Hackett (2014) gives an overview of some of the key studies. The NSPCC uses the figure of “around a third” as a mid-way point between the lower end and the higher end of the estimates.

We hold Children and young people with harmful sexual behaviours in our library.

The vast majority of children with harmful sexual behaviour have themselves experienced physical, emotional or sexual abuse.

Explanation: Research studies into children with harmful sexual behaviour are often quite small. However most do find that children with harmful sexual behaviour have also experienced other types of abuse, including sexual abuse.

We hold Children and young people with harmful sexual behaviours in our library.

How NCATS works

We work with boys and girls up to the age of 21 . They may have emotional and behavioural disorders, developmental disorders, or learning disabilities.

The team is multi-disciplinary, consisting of 4 social workers, a consultant clinical psychologist, a consultant child and adolescent psychiatrist, and a systemic family therapist.


We produce assessment reports after meeting with the young person, their parents or carers, and people within their support network such as social workers, psychologists, youth offending officers, education professionals or mental health workers. Our report includes:

  • an explanation of their harmful sexual behaviour
  • analysis of risks posed by the young person
  • recommendations, for professionals working with the young person, about case management, placement and treatment options.

Treatment services

Depending on the results of the initial assessment, we may offer individual or family-based interventions . This will usually happen alongside other care and treatment the young person is receiving. This can include things like helping the young person to:

  • make sense of their behaviour
  • develop ways to prevent the harmful behaviour happening again
  • manage their emotions and relate to others.

Professional support

We also offer consultation services such as advice and recommendations to professionals about managing complex or high-risk harmful sexual behaviour cases. It's available as a one-off service, which includes an assessment report, or ongoing consultation to a team.

NCATS provides tailored training packages to social care and health agencies, universities or at conference events around the UK.

Harmful sexual behaviour

Children and young people who develop harmful sexual behaviour harm themselves and others.
Read more about harmful sexual behaviour

Evaluating the impact

Find out how we're evaluating NCATS.

Learn more

Where NCATS is available

NCATS is based in north London but is available nationwide.

020 3772 9905



Who NCATS is for.

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Are You There?

We're calling on the government to help our Childline service be there for every child dealing with meantal health issues. 

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  1. Hackett, S., Phillips, J., Masson, H. and Balfe, M. (2013) Individual, family and abuse characteristics of 700 British child and adolescent sexual abusers. Child Abuse Review, 22(4): 232–245.

  2. Ref: McCartan, F.M. et al. (2011) Child and adolescent females who present with sexually abusive behaviours: a 10-year UK prevalence study. Journal of sexual aggression, 17(1): 4-14.