🎯 Aim
To find out whether CBT, added to usual care, is effective for patients whose depression has not improved with antidepressant medication.
Treating Depression » Wiles' Study of CBT
What you'll learn this session
Study time: 30 minutes
AQA spec: 3.2.4.5
- The aim of Wiles' study of CBT
- How the study was carried out and what it found
- What it shows about CBT for people who are still depressed on medication
- Strengths and weaknesses of the study, and how it links to holistic and reductionist ideas
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Unlock This CourseDoes CBT really work?
You have now met two treatments for depression: antidepressants and CBT. But how do we know CBT actually helps? Psychologists need evidence, and that is what Wiles and her team set out to collect. This named study is on the spec, so you need to be able to describe it and evaluate it.
Many people take antidepressants and still feel low. Wiles wanted to know whether adding CBT could help those people.
Key terms:
- Randomised controlled trial: a study where people are put into groups by chance, and one group gets the new treatment while the other gets the usual treatment, so the two can be compared fairly.
- Usual care: the normal treatment from a GP (family doctor), which here included antidepressant medication.
- Follow-up: checking on the people again after a period of time, to see if the effects last.
The study: aim, method, results, conclusion
🔬 Method
A large randomised controlled trial in the UK. Several hundred adult patients took part. All of them had depression and had already been taking antidepressants, but they were still depressed.
The patients were put into two groups by chance (random allocation):
- Usual care group: carried on with usual GP care, including their medication.
- CBT group: had usual care plus a course of CBT.
The patients were then checked again after six months and after a year. The researchers measured how much their depression symptoms had changed, using questionnaires that the patients filled in about how they felt.
📊 Results
At both six months and a year, the CBT group were much more likely to show a big reduction in their symptoms than the usual care group.
💡 Conclusion
CBT added to usual care (including medication) is effective for people whose depression has not improved on antidepressants alone.
Remember it
Think 2 groups, 2 checks: usual care vs usual care plus CBT, checked at 6 months and 1 year. The CBT group did better both times.
Evaluating the study
✅ Strengths
- Large sample: with so many patients, the results are more likely to apply to other people with depression.
- Random allocation: because patients were put into groups by chance, the two groups should be similar, so it is fair to compare them.
- Follow-up: checking after six months and a year shows whether the benefit lasts.
- Real patients: the people had real depression and were in real GP care, so the findings are useful in real life.
❌ Weaknesses
- Self-report measures: patients said how they felt on questionnaires. They may not have been honest, or may have said what they thought the researchers wanted.
- Dropouts: some patients left the study before the end, so the final results are missing some people.
- CBT alone was not tested: every patient had medication, so we cannot tell if CBT would work without it.
Link to holistic and reductionist ideas
Remember that reductionist means explaining something using one simple part, and holistic means looking at the whole person. Wiles' study supports a holistic view. Patients did best when they had medication (which works on the brain) and CBT (which works on thinking and behaviour). So treating several parts of the problem together seems better than treating only one.
Common mistakes
- Saying the study shows CBT works on its own. Everyone in the study also had usual care with medication.
- Forgetting who the patients were. They were people whose depression had not improved on antidepressants.
- Writing "the sample was small". It was a large trial, which is a strength.
- Mixing up the groups. Both groups had usual care. Only one also had CBT.
Exam-style question
(a) Describe the method used in Wiles' study of the effectiveness of CBT. [3 marks]
(b) Explain one weakness of Wiles' study. [2 marks]
Model answer
(a) Patients with depression who had not improved on antidepressants were randomly put into two groups (1). One group had usual GP care including medication, and the other had usual care plus CBT (1). Their symptoms were checked after six months and after a year (1).
(b) Everyone in the study was also on usual care with medication (1), so we cannot tell if CBT would work on its own (1).
Exam tip
For "describe the method" questions, name the two groups and say what each one received. Examiners look for "usual care" and "usual care plus CBT".