People with learning disabilities are at least as likely to suffer mental health conditions such as depression as the general population (Smiley and Cooper 2003). While cognitive-behavioural strategies are a recommended treatment for depression (NICE 2004), the effectiveness of these approaches for people with learning disabilities has been questioned – for example, through assumptions that people with learning disabilities would lack the skills to use or understand cognitive approaches.
This study by McGillivray and Kershaw aimed to compare the utility and effectiveness of both behavioural and cognitive strategies for people with learning disabilities and depression.
Group sessions for adults with learning disabilities and depression were delivered in three separate learning disability agencies. The same therapist delivered each group over twelve 1.5 hour weekly sessions.
- Groups in Agency 1 received cognitive strategies only
- Groups in Agency 2 received behavioural strategies only
- Groups in Agency 3 received both cognitive and behavioural strategies
A total of 70 individuals took part – each had depressive symptoms indicated via an informant checklist completed by staff at each agency.
Each participant completed pre- and post- group questionnaires, as well as a 6 month follow up questionnaire. The questionnaires consisted of the Beck Depression Inventory (BDI-II) to assess severity of their depressive symptoms, and a shortened version of the Automatic Thoughts Questionnaire (ATQ-R) to measure the frequency of automatic negative statements about themselves. Some participants were able to complete all questionnaires independently, while others required varying levels of assistance which was given by the therapist.
Outcome 1: Depressive Symptoms
According to the BDI-II pre-test scores, 34% of participants were ‘minimally depressed’ (score of 0-13), 40% were ‘mildly depressed’ (14-19), 19% were ‘moderately depressed’ (20-18) and 7% were ‘severely depressed (29-63).
The authors found that overall participants showed a significant improvement in their BDI-II score over time, which did not differ between groups. This suggested that all three groups were equally effective in improving clients’ depressive symptoms over time.
To determine whether these improvements were clinically meaningful the authors looked in more detail at scores for each individual with mild – severe depressive symptoms (66% of participants):
- In the Cognitive Behavioural group all individual scores improved, and over half (53%) received a score of 13 or less indicating recovery from their depressive symptoms. These changes were maintained at follow up 6 months later.
- In the Cognitive only group 73% improved their scores and 43% recovered (increasing to 53% 6 months later).
- In the Behavioural only group, 82% improved their scores however only 47% maintained improvement after 6 months. 71% recovered however again this decreased to 47% after 6 months.
Outcome 2: Automatic negative thoughts
Evaluation of participants’ ATQ scores indicated that overall participants’ scores significantly decreased over time. There was no overall significant difference between each group, however there was a statistically significant decrease between the pre- and post- group scores for the Cognitive Behavioural group. This was not found in either the Cognitive or Behavioural groups.
Overall, results were not wildly different between the three groups with all groups showing significant improvements in both depressive symptoms and automatic thoughts. Teasing the data apart a little more the authors found that the Cognitive Behavioural group may have had some small advantages: the scores for those with mild, moderate or severe depression improved the most and were maintained 6 months later. In addition, automatic thoughts improved significantly more during the Cognitive Behavioural group.
Strengths and Limitations
When comparing the effectiveness of interventions it is important to keep all things equal between groups so that the only difference is the intervention type people receive. In this study each intervention was delivered in a different agency. This means that any features that differed between agencies (staff, size, activities available…) could have had an impact on the results achieved and therefore we cannot assume that differences in score were purely due to the intervention type. As an example, it is possible that staff from one agency may have spent more time supporting group members to practice their strategies, resulting in a greater improvement in DBI-II and ATQ-R scores than the group alone would have achieved.
In addition, a large proportion of participants had minimal depression, i.e. a level below that identified as clinically significant. Not only will this have reduced the possibility for post-intervention improvements in score, but is also unrepresentative of the clients who would typically access or be referred for such interventions.
Moreover all had mild LD meaning that these findings cannot be generalised to the wider LD population (for example those with more moderate or severe LD who would need additional support and resources to partake in such groups).
The authors also describe how some participants required help completing the questionnaires which may have impacted on the way they answered these questions. For example people with learning disabilities can be acquiescent and may have answered questions in a way they thought would please the therapist.
The authors do provide some details about each group’s content (e.g. use of role play to aid learning, and communication strategies) however it would have been helpful to know if and how resources for the group were made accessible for people with learning disabilities. Without this sort of information it can be difficult for clinicians to incorporate these strategies into their practice, or for researchers to replicate and expand on the findings.
McGillivray and Kershaw explore the use of cognitive and/or behavioural strategies in ‘real’ settings, and evidencing improvements in the real world like this is extremely valuable. However, this strategy comes with limitations as described above, and a more rigorous and controlled methodology may be necessary to address these. While this paper probably does not provide enough evidence to transform the way therapy is delivered to people with LD and depression, it certainly challenges assumptions about the value of cognitive strategies for this group, and paves the way for future research in this area. For example, it would be interesting to find out if and how these results might differ for 1-1 approaches.
McGillivray, J. A., & Kershaw, M. (2015). Do we need both cognitive and behavioural components in interventions for depressed mood in people with mild intellectual disability? Journal of Intellectual Disability Research, 59(2), 105-115 [abstract]
National Institute for Clinical Excellence (2004) Depression: management of depression in primary and secondary care, Clinical Guideline no. 23, London.
Smiley E. and Cooper S. (2003) Intellectual disabilities, depressive episode, diagnostic criteria and diagnostic criteria for psychiatric disorders for use with adults with learning disabilities/mental retardation (DC-LD). Journal of intellectual disability research (47) 62-71