There is a captivating story in Alice鈥檚 Adventures in Wonderland1 where the young Alice is confronted by sudden and unexpected changes in her appearance. She sits down and begins to cry. Her best efforts to talk herself out of her distress come to nothing. Instead, frightened and distraught, she goes on to shed gallons of tears, until there is a large pool all round her. Her sadness is quite overwhelming and eventually she exclaims: 鈥榃ho in the world am I?鈥� followed by 鈥業 am so very tired of being all alone here!鈥�
Alice soon becomes worried that she might be punished for crying too much, and tries to find her way out of her pool of tears. When she comes across a mouse, Alice asks it for help. The mouse looks at her rather inquisitively, but initially says nothing. When Alice inadvertently starts talking fondly about her cat, Dinah, the mouse is startled and forbids her to mention her name again. Alice agrees, 鈥榃e won鈥檛 talk about her any more if you鈥檇 rather not,鈥� and tries to change the subject by talking about a nice little dog near her house. This time, the mouse has had enough and swims away as fast as it can go. Alice quickly promises not to talk about cats and dogs anymore, and the mouse returns slowly to her.
By this time the pool (of tears) is getting quite crowded with birds, animals and other 鈥榗urious creatures鈥� that have fallen into it. Eventually, the whole party swims to the shore. Upon arrival, they are dripping wet, cross and uncomfortable. Nevertheless, the most pressing issue is how to get dry from swimming in the pool of tears. The group starts to quarrel about the best way to do this. Initially, the Lory bird argues that it is older and must therefore know better than the others. But soon the mouse stamps its authority on the group, exclaiming: 鈥楽it down, all of you, and listen to me! I鈥檒l soon make you dry enough!鈥� The mouse delivers his remedy with aplomb, not allowing any interruptions or questions.
When, as psychotherapists, we encounter a child or a young person who is sad and depressed like Alice, we can hear the advocates of different psychological therapy models telling us what is best to do. It could be an advocate of an older model, appealing to our sense of respect for the wisdom of our elders. Or it could be an advocate of a newer model, speaking with the confidence of the young.
At present, one model 鈥� CBT 鈥� is heavily promoted to dry children and young people from swimming in their pools of tears.
What works for a child in tears?
When asked why CBT should be used rather than any other recognised form of psychological therapy, its advocates regularly point to its 鈥榮uperior evidence base鈥�. It is claimed that empirical studies using randomised controlled trials (RCTs) show that CBT is more effective than other recognised psychological therapies for treating children and young people who have been diagnosed with depression. What should we make of these claims? Do these studies really provide the unequivocal 鈥榚vidence鈥� that CBT advocates like to claim?
I recently published a paper based on my own efforts to review the quality of the evidence and its interpretation.2 I looked specifically at the 2005 National Institute for Health and Care Excellence (NICE) guideline on Depression in Children and Young People,3 as this document continues to form the basis of what treatments should be available on the NHS in England and Wales. Since the guideline was published, a dominant narrative has developed that individual CBT is superior to other psychological therapies and that it should be provided to all children and young people in CAMHS who have been diagnosed with depression. As in Alice鈥檚 story, we are often told to accept this narrative without questioning or interrupting.
The NICE guideline references four RCTs where individual CBT was compared to another psychological therapy intervention, a non-specific control intervention and/or wait-list.4鈥�7 I considered these trials separately before looking at the overall evidence that they provide when the findings are considered as a whole. A trial comparing individual CBT to a non-psychological intervention (medication) was also cited by NICE, and I considered this trial separately from the other four.8
The interpretation of statistical data as evidence is a crucial issue in experimental research. In the full guideline, NICE concluded that the overall evidence for the effectiveness of individual CBT was 鈥榠nconclusive鈥�. This is an acknowledgement that the evidence base that underpins the guideline is limited, and what evidence there is, is weak. To get around the problem of the lack of significant evidence for individual CBT in the four RCTs, NICE chooses to talk of 鈥榗linically important improvement鈥� rather than 鈥榮tatistically significant improvement鈥�. The problem here is not so much the use of the concept 鈥榗linically important improvement鈥�. However, if you want to base the superiority of your evidence claims on the fact that you employ 鈥榞old standard鈥� RCTs, then you also have to accept if this method of inquiry does not yield the results that you might want.
There are numerous other problems with these four trials and how their results were interpreted. None of the trials included a single child under the age of eight years, with the majority of participants at least 13 years old. Although the full NICE guideline cautions readers against assuming that their conclusions apply to younger children, this advice is clearly not heeded by those responsible for the initial CYP-IAPT training curriculum.9 The first training manual states that CYP-IAPT workers will be trained in the NICE guidance to deliver CBT for children and young people, and that they will learn to adapt a CBT approach to younger children presenting with depression.
All four trials had small sample sizes. While this is not unusual for these sorts of trials, they nevertheless suffered from a lack of power. Although all four studies used the DSM-III-R to decide who could be included in their trials, what qualified as 鈥榙epression鈥� and how it could be determined varied from study to study. Similarly, all four studies used different exclusion criteria and, perhaps more importantly, excluded children and young people with other co-morbid problems. This matters, because in all the years that I have worked as a clinician, I have rarely come across a child or young person who presents with a single, uncomplicated problem. The four studies all purport to have used individual CBT as the intervention for which efficacy was being evaluated. However, a closer look reveals that the 鈥楥BT鈥� that was used varied from study to study. Each version of CBT had its own unique protocol. Also, there was no consistency across the four studies regarding the instruments and protocols used to measure the effectiveness of the individual CBT that was provided. Finally, two of the four trials were conducted outside the UK, raising some issues relating to the ecological validity of the findings for a UK context.
The Treatment for Adolescents with Depression Study (TADS)8 is an altogether more robust piece of research with a large trial and a sound design. However, there are a number of problems with this study as well. For example, a significant number of participants (56%) were volunteers recruited through advertisements rather than from actual clinical settings. There was a large dropout rate (28%) from the CBT group in the trial. No child under the age of 12 was included. Most strikingly, when CBT on its own was compared to a blinded pill-placebo at a 12-week interval, no statistically significant difference was found. Nevertheless, the authors conclude that CBT should be the treatment of choice for adolescents who have been diagnosed with depression. This is in stark contrast to a comprehensive recent Cochrane review which concluded that, based on the available evidence, the effectiveness of interventions for treating 鈥榙epressive disorders鈥� in children and adolescents (including individual CBT) cannot be established.10
The wisdom of the Dodo bird
Let鈥檚 return to Alice鈥檚 pool of tears. After the mouse confidently delivered his remedy, he asked Alice how she was now getting on, to which she replied in a melancholy tone: 鈥楢s wet as ever, it doesn鈥檛 seem to dry me at all.鈥� At this point, the Dodo proposed that they immediately adopt more energetic remedies. He proposed that the best thing to get them dry would be for everyone to participate in a 鈥楥aucus-race鈥�. He marked out a racecourse, with everyone placed here and there along the course. However, it was a curious race: 鈥楾here was no 鈥淥ne, two, three, and away鈥�, but they began running when they liked, and left off when they liked, so that it was not easy to know when the race was over.鈥� Nevertheless, after a while everybody was quite dry again and the Dodo declared that the race was over. But who had won? The Dodo thought about it carefully for a long time, and at last declared: 鈥楨verybody has won, and all must have prizes.鈥�
In 1936 the psychologist Saul Rosenzweig, a friend and classmate of the behaviourist BF Skinner, published a paper discussing 鈥榗ommon factors鈥� underlying a range of popular and competing approaches to psychotherapy. He argued that all forms of psychotherapy, when competently employed, could be equally effective.11 This idea, that positive psychotherapy outcomes are likely to be due to competent therapists sharing common factors, rather than specific techniques, became known as the Dodo bird hypothesis.
Three decades later another psychologist, Lester Luborsky, led a team using modern statistical methods to test the validity of the Dodo bird hypothesis.聽They determined that most of the positive effect that is gained from psychotherapy is due to factors that different approaches have in common, namely the therapeutic effect of having a relationship with a therapist who is warm, respectful and friendly.12 This conclusion became known as the Dodo bird effect. Luborsky et al13 showed that the effect size that can be attributed to specific therapy techniques is only 0.20 (Cohen鈥檚 d). This small and non-significant effect size, based on 17 meta-analyses, shrank even further when corrected for the therapeutic allegiance of the researchers involved in comparing the different psychological therapies.12 Their findings are in line with another large-scale review of treatment comparisons of active treatments that found a similar effect size: (Pearson鈥檚 r=0.19).14 Based on these findings, one might conclude that all bona fide psychological therapies can be equally effective and therefore 鈥榓ll must have prizes鈥�.
Making tears pay
So why are so many CBT therapists not content with their prizes, but work so hard to position CBT as the most-prized psychological therapy? There is no single answer to this question, but it is worth briefly looking at the wider context. Much has been written about the medicalisation of misery through the production of psychiatric diagnoses (for example, see Moncrieff et al).15 However, the production of psychiatric diagnoses is not only a medical activity 鈥� it has also become a lucrative commercial activity, a marketplace if you like. Treating psychiatric 鈥榙isorders鈥� has developed into a big business, and the monetary prizes are equally big. IMS Health, a market research company, estimated that by 2006 antidepressants had become the most commonly prescribed class of drugs in the US, accounting for $13.6 billion of sales in the US alone and $19.7 billion globally. By 2007 three of the 10 best-selling medications worldwide were psychiatric medicines. According to IMS Health,16 the combined global sales of antidepressants and antipsychotics in 2011 were $48.4 billion, roughly 锟�30.1 billion in today鈥檚 rates. To put this in some perspective: according to the Office of Health Economics,17 the total UK NHS spend on medicines (GP and hospital) in 2011 was 锟�13.6 billion (at list prices), so 锟�30.1 billion would have funded all medical drugs in the NHS for more than two years.
To compete for a share in this lucrative market, it is essential to convince buyers and consumers not only of the superior efficacy of your product (through effective marketing campaigns), but also its cost effectiveness compared to other rival products. And this is CBT鈥檚 pitch when it comes to the treatment of children and young people who have been diagnosed with depression: 鈥極ur treatment is superior to other (psychological) interventions, and is more cost effective (than medication).鈥� But as we can see from taking a closer look, the clinical effectiveness of individual CBT for children and adolescents who have been diagnosed with depression is clearly overstated.2 Is it more cost effective? I don鈥檛 know, but in this commercialised context of mental distress, it helps, of course, if you can recruit an eminent economist as your main cheerleader. Lord Richard Layard makes a passionate case for the use of evidence-based psychological therapy (rather than psychiatric drugs) to reduce the economic costs of child, adolescent and adult mental health problems. And he likes to refer to the NICE guidelines when proposing which psychological therapy has won the evidence race and should be awarded all the prizes.
Of course, he would not take the advice of a fictional Dodo bird seriously, but perhaps he should take the evidence, or lack thereof, more seriously.
Will it all end in tears?
I agree with those who point to the tenacious veracity of the Dodo bird verdict. We should invest less effort in trying to prove that one specific psychological therapy model wins every time, and more effort in systematically applying the common factors inherent in a relational model of therapist competence. This, in my view, is also true in relation to the treatment of children and adolescents who have been diagnosed with depression. Finally, the Dodo bird cautions us to beware ambition, hubris and greed around one model of psychotherapy getting all the prizes. It may yet end in tears, a pool of tears, regardless of our preferred models. And who would dry these tears?
Pieter W Nel is Reader in Clinical Psychology Training at the University of Hertfordshire, UK, and also practises as a consultant clinical psychologist in CAMHS. He has a broad interest in alternatives to more orthodox approaches to clinical psychology education and practice, including non-pathologising models of working with children and families in psychological distress.
References
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