Complex Behaviour Service: is it really an enhanced model for challenging behaviour?


Challenging behaviour relates to behaviour that may be harmful and destructive to the self and others; often resulting in injury and damage both physical and to property. Unfortunately, individuals who have learning disabilities are more likely to display behaviour that falls into this ‘challenging’ category.

It is becoming increasingly more frequent to hear of individuals with a diagnosis of learning disabilities and challenging behaviour being relocated to other parts of the country, away from home, family and friends, to receive specialist care for their needs. However, the motives behind these decisions from funding bodies have been suggested to not always take a person-centered approach. Currently in the UK, service funds are being cut, budgets are tight and the level of care and support for individuals with learning disabilities, let alone those with challenging behaviour, are being compromised. A study by The Association of Support Living (2011) found the relocation of 10 service users to out of county services saved the local authority a whopping £900,000 per year! Consequently, the underlying motives for these moves could be questioned.

In response to these changing funding needs both for individuals with learning disabilities and care providers, plus the ever apparent changes in the social care climate, a London borough commissioned a Challenging Behaviour Service (CBS) consisting of 2 psychologists, a behaviour support worker, and a psychology graduate, to work across services providing an integrated, visible, partnership approach to supporting challenging behaviour positively. This service focused intervention methods on principles of positive behaviour support (PBS), working within and across support and care services to analyse behaviour, identify function and suggest pro-active solutions and strategies.

This paper aimed to evaluate the effectiveness of this CBS model over a year long period (Inchley-Mort, 2014).

The Challenging Behaviour Service used principles of positive behaviour support.

The Challenging Behaviour Service used principles of positive behaviour support.



  • Participants were 24 service users of the CBS, and a control group of 22 service users not in the CBS (non-CBS)
  • All services users had been identified as having challenging behaviour. Those with acute mental health needs and substance abuse issues were removed


  • The CBS service was implemented in an inner London learning disability service
  • Observational data was collected at three intervals:
    • Baseline
    • 6 months
    • 12 months

Primary outcome

  • The improvement of challenging behaviours (Aberrant Behaviour Checklist- Amman et al.1985)

Secondary outcomes

  • Mental and social functioning (HoNOS-LD; Roy et al., 2002).
  • Assessment of met and unmet needs (Camberwell Assessment of Needs-Developmental and Intellectual Disabilities-short version (CANDID-s; Xenitidis et al., 2000)
  • Mental health status (PASSAD; Moss et al., 1998)

Researchers also took a quantitative measure of the level of risk that the individuals in the CBS posed to themselves, others and the community. Current social care costs and information on support arrangements were also gathered for each individual.


Adjusted and unadjusted multilevel regression analyses were used:

  • At 6 months the CBS group showed a significant reduction (mean differences (95% CI) based on the adjusted analysis) compared to controls in their:
    • Sleep 4.7 (0.6 to 8.8)
    • Stereotypy 2.0 (0.4 to 3.7)
    • Total scores from the ABC 11.8 (0 to 23.6)
  • At 12 months, the only significant between group difference was stereotypy scores (mean difference 1.5; 95% CI 0.2 to 2.9)
  • No differences were found between the CBS and Non-CBS control group at the 12 month period


  • The level of risk within the CBS group had dropped 11.35% from baseline at 12 months
  • Weekly social care costs increased in the CBS group over the treatment period (mean increase of £495.87 per week) whilst appeared to decrease in the non-CBS group (mean decrease of £152.64 per week)
Short-term improvements from CBS were not maintained at 12 months.

Short-term improvements from CBS were not maintained at 12 months.


The researchers felt that the CBS service reflected good working practice and provided a cost effective support method for individuals with challenging behaviour. They point to the findings that show after a 6-month period some scores on the ABC had decreased in the CBS group compared to non-CBS. However, we can’t ignore that at 12 months no real difference between the CBS and non CBS group had been found; suggesting that the CBS had not been as effective a service intervention as was originally intended. Why might this be?

Firstly, let’s look at the limitations:

  • Uncontrolled design: the authors themselves acknowledge that a randomised controlled design would have eradicated group differences at the baseline level and may therefore have produced quite different findings
  • Financial data was taken from the service directly and the subsequent analysis did not take a health economics perspective
  • The CBS was part of a wider team and this study did not take into account the practice in place from other professionals, which may have impacted on results

The paper also addresses the pertinent issue that in order to integrate new ways of supporting individuals with learning disabilities and challenging behaviour in their own community, changes need to be made at the top. Specifically they refer to the need to seek evidence-based findings on what actually constitutes a positive, proactive and effective challenging behaviour service for people with learning disabilities. As the authors point out, this evidence is not currently available in the UK.

It would be great to continue to evaluate the effectiveness of integrated and cross-service support for people with learning disabilities (such as the CBS) but this can’t reliably be implemented until we have evidence-based research into the service design of more fundamental support and care.

A randomised controlled trial would have provided a more reliable result in assessing the effectiveness of the Challenging Behaviour Service.

A randomised controlled trial would have provided a more reliable result in assessing the safety and effectiveness of the Complex Behaviour Service.


Primary paper

Inchley-Mort, S., Rantell., K., Wahlich, C., and Hassiotis, A. (2014) Complex Behaviour Service: enhanced model for challenging behaviour. Advances in Mental Health and Intellectual Disabilities, Vol. 8 Iss 4 pp. 219 – 227. [Abstract]

Other references

Aman, M.G., Singh, N.N., Stewart, A.W. and Field, C.J. (1985), “The aberrant behavior checklist: a behavior rating scale for the assessment of treatment effects”, American Journal of Mental Deficiency, Vol. 89 No. 5, pp. 485-91.

Association of Supported Living (2011), There is an Alternative, Association of Supported Living, Loughton.

Roy, A., Matthews, H., Clifford, P., Fowler, V. and Martin, D.M. (2002), “Health of the nation outcome scales for people with learning disabilities (HoNOS–LD)”, The British Journal of Psychiatry, Vol. 180 No. 1, pp. 61-6.

Moss, S., Prosser, H., Costello, H., Simpson, N., Patel, P., Rowe, S., Turner, S. and Hatton, C. (1998), “Reliability and validity of the PAS-ADD Checklist for detecting psychiatric disorders in adults with intellectual disability”, Journal of Intellectual Disability Research, Vol. 42 No. 2, pp. 173-83.

Xenitidis, K., Thornicroft, G., Leese, M., Slade, M., Fotiadou, M., Philip, H., Sayer, J., Harris, E., McGee, D. and Murphy, D. (2000), “Reliability and validity of the CANDID – a needs assessment instrument for adults with learning disabilities and mental health problems”, The British Journal of Psychiatry, Vol. 176 No. 5, pp. 473-8.

Photo credits

Share on Facebook Tweet this on Twitter Share on LinkedIn Share on Google+
Mark as read
Create a personal elf note about this blog
Rachel Allan

Rachel Allan

Rachel Allan was previously a Practice Lead working for The Royal Mencap Society, supporting and developing good practice in services for individuals with a wide range of complex disabilities. She graduated in psychology and went on to study both developmental psychology and mental health at post-graduate levels. Rachel has previously worked in many different care and educational settings for children, young people and adults with a wide range complex learning disabilities. She has also worked within academic research, specifically completing a two-year research associate post looking at the mental health of individuals with profound and multiple needs (PMLD). She is particularly interested in person centred planning, supporting the mental health and well-being of people with complex disabilities, and more recently, the effects of trauma and abuse in this group of individuals. Having recently taken voluntary redundancy from her role at Mencap, Rachel is now enjoying some free time (!?) to explore her personal interests while she assesses what may be the next chapter in life.....

More posts

Follow me here –