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Functional Family Therapy Gangs (FFT-G)

An intensive, home-based, family therapy programme, that provides 3-5 months of therapy to families.

Evaluation type

Pilot study
See project

Organisation name

Family Psychology Mutual

Funding round

Launch grant round




East of England

Activity Type

Psychological therapies




University of Greenwich


July 2021

What does this project involve?

Functional Family Therapy Gangs (FFT-G) is an intensive, home-based programme that provides three to five months of therapy to families. It aims to improve the safety, well-being and stability of children and families, and reduce offending.

The programme was developed by FFT LLC and delivered by Family Psychology Mutual (FPM). It’s targeted at 10-to-17 year olds at risk of involvement in county lines drug networks or child criminal exploitation. In the early stages, contact is provided to families several times a week, with home visits lasting 60 to 90 minutes. In later stages of the intervention, contact is reduced to weekly.

Why did YEF fund this project?

County lines drug networks are organised networks involving the transportation of, primarily, class A drugs from urban to rural areas. Gangs and organised crime groups exploit vulnerable young people to transport or store drugs as part of these networks. They are also known to facilitate and promote particularly violent behaviour.

This practice represents one form of child criminal exploitation, defined by the Home Office as ‘where an individual or group takes advantage of an imbalance of power to coerce, control, manipulate or deceive a child or young person’. Many of the young people exploited in this way are often known to child social care services. Unfortunately, there’s a lack of evidence informing how to prevent child exploitation in county lines drugs networks, while services face a wide-range of challenges in tackling the problem.

Functional Family Therapy Gangs (FFT-G) has shown promise in other contexts in engaging young people at high-risk for gang involvement and reducing re-offending. Given the lack of evidence-based interventions for tackling county lines involvement, we funded a feasibility and pilot study of FFT-G to learn more about the programme.

The feasibility study aimed to ascertain how feasible a randomised pilot study of the programme would be. It explored whether caseworkers would refer young people to an randomised control trial (RCT), analysing what the most productive referral pathways were, and evaluating whether enough referrals would be received to ensure adequate therapist caseloads. These questions were explored using 19 interviews with key professionals, randomised data gathering and a document review. The intervention was delivered to 48 families in the London Borough of Redbridge – their Family Intervention Team (FIT), part of specialist services for vulnerable children within social care, referred young people to the programme. The feasibility study was delivered between October 2019 and March 2021.

The pilot study then aimed to explore how many families were eligible for FFT-G, analysed the barriers to, and implementation of, trial recruitment, and examined a range of questions relating to the design of a potential future large-scale RCT (such as how many families can be randomised and how often; the rates of missing data at baseline testing; attrition rates; and, the effect sizes associated with the intervention). These questions were explored via the delivery of a pilot RCT, again delivered in the London Borough of Redbridge. 23 young people’s families received the intervention, while 22 received service as usual. 9 interviews were also conducted with families. The pilot took place between March 2021 and July 2021. Both the feasibility and pilot studies were impacted by the coronavirus pandemic, requiring both the delivery and evaluation teams to adapt to challenging circumstances.

Key conclusions

Interviews with caseworkers in the feasibility study suggested that they would, albeit reluctantly, refer young people and their families to the programme to participate in an RCT. The most common reason given was to ensure the continuation of the service. A waitlist control was preferred by some caseworkers, but the evaluator adjudged a parallel RCT to be preferable.
In the feasibility study, FFT-G received a reasonable number of referrals (100 over 13 months), although this was lower than anticipated by therapists. The evaluator deemed completion rates to be adequate; where treatment data were collected, 61% of families enrolled completed the treatment.
The pilot study found that 95 families were identified over nine months in LBR to receive the programme – 73% (69) of them were eligible for the programme after full screening, out of which 66% (45) progressed through recruitment to be randomised into the pilot RCT.
Missing data rates in the pilot RCT were low at baseline. The RCT then measured parent-reported family functioning and young person-reported conduct problems. There was a 20% attrition rate. The evaluator deemed that in a small efficacy RCT, recruitment would be possible using only one local authority (LA). Given sample size calculations, they predicted that a sample between 51 and 248 would be required and advised aiming for the higher end of this range.
In the pilot study, 74% of families received eight or more sessions, and 83% completed the programme. In terms of what the families in the service as usual group were receiving, approximately one third received an alternative parenting programme; 27% do not appear to have received any services.

What will YEF do next?

Given these early, promising findings, we’ve decided to fund a further evaluation of FFT-G and will be setting up an efficacy RCT.

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