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Magill M., Ray L.A.
Journal of Studies on Alcohol and Drugs: 2009, 70, 516–527.
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Cognitive-behavioural therapies are among the most widespread and influential approaches to substance use, yet this analysis found they conferred just a small advantage over other therapies. Perhaps other features are more important than the therapeutic 'brand'.
Summary Cognitive-behavioural These therapies target cognitive, affective, and situational triggers for substance use and provide skills training specific to coping alternatives. For alcohol or illicit drug use, these approaches often include the following strategies: identifying intrapersonal and interpersonal triggers for relapse; coping skills training; drug refusal skills training; analysis of the functions substance use serves for the patient; and promoting activities related to non-use of substances. treatment models are among the most extensively evaluated interventions for alcohol or illicit drug use disorders, yet this body of work has not been synthesised using meta-analytic A study which uses recognised procedures to summarise quantitative results from several studies of the same or similar interventions to arrive at composite outcome scores. Usually undertaken to allow the intervention's effectiveness to be assessed with greater confidence than on the basis of the studies taken individually. techniques since 1999. This analysis aimed to update earlier analyses by synthesising results from randomised controlled trials of cognitive-behavioural treatment for adults diagnosed with alcohol or illicit drug use disorders, and to extend these analyses by identifying client or treatment factors which predict the magnitude of the treatment's impact. 52 studies One of the studies (Project MATCH) had two arms testing the interventions on different samples of drinkers, so contributed two results to the analysis. published in English between 1980 and 2006 were found, involving 9308 individuals. Most were conducted in the USA. 80% The remainder also enrolled individuals with a diagnosis of abuse. enrolled only individuals diagnosed as dependent on alcohol or other drugs. About two thirds did not exclude people with psychiatric problems. Other than suicidal or homicidal ideation and active psychosis. Nearly all used manual-guided programmes. An effect size A standard way of expressing the magnitude of a difference (eg, between outcomes in control and experimental groups) applicable to most quantitative data. Enables different measures taken in different studies to be compared or (in meta-analyses) combined. Based on expressing the difference in the average outcomes between control and experimental groups as a proportion of the variability in the outcome across both groups. the most common statistic used to quantify this difference is called Cohen's d. Conventionally this is considered to indicate a small effect when no greater than 0.2, a medium effect when around 0.5, and a large effect when at least 0.8. was calculated for each study to provide a common metric for expressing the strength of impact When these were available, biological tests of substance use were relied on, then assessments of substance use frequency, and when neither of these was available, proportions of the samples recorded as using substances. of the interventions.
Most of the studies compared cognitive-behavioural therapies against treatment as usual, many against other specific therapies, and a few against no treatment. Another few tested cognitive-behavioural therapies as an add-on treatment. Across all these studies, cognitive-behavioural therapies improved substance use outcomes by a small but statistically significant degree. The size of this effect meant that with cognitive-behavioural therapy, another 8% of people would do better than the typical Specifically, 58% of cognitive-behavioural patients performed better than the median for the comparison group. person in the comparison group whose treatment did not include cognitive-behavioural therapy. However, there was significant variation in impact across the studies.
As expected, the therapy's effectiveness was thrown in to sharpest relief when compared to no treatment. The large effect size across these studies meant that another 29% of people had better substance use outcomes than the typical non-treated individual in the comparison group. Once again however, there was significant variation in impact across the studies. In contrast, there was a consistent but much smaller improvement in outcomes when the comparison group received either treatment as usual, or another specific therapy.
Contradicting conclusions reached by other analysts, there was no evidence that the benefits of cognitive-behavioural therapies persisted and/or grew over time more than those from other approaches. Impacts registered in studies with post-treatment follow-ups were slightly lower than the overall impact, and the relative benefits of cognitive-behavioural therapies diminished between 6–9 months after treatment and 12 months.
Across the six studies where the main problem drug was cannabis, cognitive-behavioural therapies had a consistent moderate impact which was larger than the all-drugs average. This meant that instead of (as across all the studies) another 8% of people doing better than typical for the comparison group, in the cannabis studies the figure was 19%. Impacts remained significant and consistent but small for alcohol studies, variable and small when the problem drugs were either stimulants or opiates, but became insignificant when the participants used multiple drugs.
Among the more detailed findings were that no overall advantage was gained when cognitive-behavioural therapy was an add-on to another treatment programme. However, in most studies the core programme was a contingency management regimen rewarding patients for abstinence and/or recovery-promoting activities, and the findings were variable across the studies to the point where leaving out one outlier resulted in a significant positive impact. Whether therapy was delivered in an individual or group format, or as part of the initial treatment or as aftercare, made no significant difference to its effectiveness. There was a larger impact when the therapy supplemented other psychosocial therapies than when it supplemented medication-based treatment, but this finding was too dependent on the particular studies included in the analysis to be considered a generalisable principle. The relative benefit of cognitive-behavioural therapies was unaffected by the age of the participants or whether they suffered from mental illness, but was stronger the more women were included in the samples – possibly an artefact of other features Specifically, study sample size and the strength of the comparison condition. of the studies. Cognitive-behavioural programmes with fewer sessions tended to have greater benefits, but this might have been because the more extended programmes were compared against stronger alternative treatments. Even when these and other features of the studies had been taken in to account, there remained significant variation in the extent to which cognitive-behavioural therapies improved substance use outcomes.
The analysts concluded that cognitive-behavioural therapies had demonstrated their utility across a large and diverse sample of studies and for different types of substance use dependencies, and had done so under rigorous conditions for establishing efficacy, including comparisons with other active treatments. Effects were strongest among cannabis users and might also have been larger with women, when the therapies were relatively brief, and combined with another psychosocial therapy rather than medication. Group-based delivery was no less effective than individual.
commentary Cognitive-behavioural approaches are perhaps the world's most commonly used and widely researched formal psychological therapies, applied often with good results to a range of psychological problems. For substance use too, these therapies have an impressive research record (for example for problem drinking), but this is partly because more good quality studies have been done than in respect of competing approaches.
Despite its prominence, theoretical pedigree, and an extensive research effort which has refined the therapy in to expert manuals (for example, 1 2), the featured analysis indicates that overall the advantage conferred by cognitive-behavioural therapies over the alternatives is minor. That verdict is all the more disappointing since in many cases the alternatives For example relaxation, education, non-directive social support group, brief motivational counselling, meditation, discussion groups, supportive counselling. seemed weak and/or not designed to be therapeutic. It is by no means clear that cognitive-behavioural therapies are more effective than other similarly extensive and coherent approaches. Studies which directly tested this proposition often found little or no difference, even when the competing therapy amounted simply to well structured medical care (1 2). Reviewers too have broadly reached this conclusion in respect of the use of substances in general, cannabis in particular (1 2), methamphetamine, and these and other stimulants, including cocaine. In respect of alcohol problems, a recent analysis has concluded that any differences between outcomes from psychosocial therapies are likely to have been due to chance or the allegiance of the researchers. Finally, a meta-analysis A study which uses recognised procedures to summarise quantitative results from several studies of the same or similar interventions to arrive at composite outcome scores. Usually undertaken to allow the intervention's effectiveness to be assessed with greater confidence than on the basis of the studies taken individually. has combined results from studies comparing cognitive-behavioural therapies only to other well structured and specified psychotherapies rather than to deliberately weaker alternatives. The review included patients with a variety of psychiatric complaints, including substance use problems. It found cognitive-behavioural therapies clearly preferable for depression and anxiety but not On the basis though of just three studies. substance use problems.
In the featured analysis, only with respect to cannabis use studies did cognitive-behavioural approaches record a major advantage. But of these six studies, three included no-treatment control groups, and when there was a comparison treatment, often it was much briefer then the cognitive-behavioural therapy, or in one case, deliberately non-interventionist. Greater impact across these studies might simply have reflected the relative weakness of the comparators.
Findings of little difference between outcomes from different therapies fit with the discovery that, despite in theory working through very different psychological processes, in practice cognitive-behavioural and other therapies create change through similar mechanisms. Studies have rarely confirmed that the theoretical mechanisms behind cognitive-behavioural therapies actually were responsible for substance use outcomes. Such findings direct attention away from the 'brand' of the therapy to 'common factors' which cut across different therapies, such as entering a setting within which the patient expects to be helped to get better, the credibility of the therapy to both patient and therapist, its ability to (for that patient) make ordered sense of the patient's 'disorder', in doing so to structure a route out of that disorder which generates optimism, its ability to provide a platform for engaging the client in their recovery, and the therapist's ability to create a supportive environment which facilitates these processes. Perhaps the greatest common factor lies in the patients and clients. Typically they have reached the point where they desperately want to get better, have realised they need help to do so, and have decided to follow a culturally sanctioned route to gaining that help – formal treatment.
Beyond the type of therapy, promising routes to improving outcomes include focusing on the interpersonal style of the therapist, including the degree to which they exercise discretion and flexibility, and dimensions of the therapies such their degree of structure, directiveness, focus on emotional content, emphasis on engineering social support, and how far these match the personality and needs of the patient. In turn, common factors and therapeutic dimensions are nurtured or obstructed by the service's organisational climate Such as its openness to change and new learning, and an atmosphere of trust in which staff can exchange views and raise issues. and the quality of its procedures. Such as whether patients are effectively encouraged to attend, adequately assessed and provided the services they need, proactively linked with other sources of support, and continue to be monitored after initial treatment. In turn these features are nested within the wider regulatory and professional environment. See these earlier Findings analyses for more on common factors (1), therapeutic styles and cross-cutting features of therapies (1 2 3 4 5 6 7), organisational climate (1) and procedures (1 2 3 4 5 6 7 8), and the wider environment (1 2).
Where cognitive-behavioural approaches sometimes have scored better than alternatives is in the persistence of their effects. Gains relative to other therapies have been found to emerge only after the end of therapy and to grow over the follow-up period. This has been observed for some psychological and psychiatric problems (1 2), for cocaine use problems (1 2), and recently in respect of cannabis dependence. The featured analysis seems to contradict this impression, but its finding of diminishing returns in the year after treatment reflects results from different sets of studies at the different time periods. Other ways the studies differed might account for this apparent waning. More convincing are results from different time points within the same study.
Recent national guidance from Britain's National Institute for Health and Clinical Excellence (NICE) recommended against cognitive-behavioural therapy as a routine treatment for drug problems, suggesting its main role was in tackling accompanying depression and anxiety. However, the analyses on which this was based did not show that cognitive-behavioural therapy was ineffective, just that it was not convincingly more effective than other well structured therapies. If this is the case, then the decision between such therapies can safely be taken on the grounds of what makes most sense to patient and therapist, the therapist's training, availability, and cost. In respect of cost and availability, cognitive-behavioural therapy may (more evidence is needed) prove to have two important advantages. The first is that effects may persist and even amplify without having to continue in therapy. The second is that it lends itself to manualisation to the point where it can be packaged as an interactive computer program and made available in services lacking trained therapists – potentially a crucial advantage for widespread implementation. In the UK implementation has been held back by the shortage of therapists, an obstacle currently being addressed by a government-funded training initiative.
Thanks for their comments on this entry in draft to Molly Magill of the Center for Alcohol and Addiction Studies at Brown University in the USA. Commentators bear no responsibility for the text including the interpretations and any remaining errors.
Last revised 28 July 2010
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