Jürgen Barth and colleagues use network meta-analysis - a novel methodological approach - to reexamine the comparative efficacy of seven psychotherapeutic interventions for adults with depression.
Please see later in the article for the Editors' Summary
Previous meta-analyses comparing the efficacy of psychotherapeutic interventions for depression were clouded by a limited number of within-study treatment comparisons. This study used network meta-analysis, a novel methodological approach that integrates direct and indirect evidence from randomised controlled studies, to re-examine the comparative efficacy of seven psychotherapeutic interventions for adult depression.
Methods and Findings
We conducted systematic literature searches in PubMed, PsycINFO, and Embase up to November 2012, and identified additional studies through earlier meta-analyses and the references of included studies. We identified 198 studies, including 15,118 adult patients with depression, and coded moderator variables. Each of the seven psychotherapeutic interventions was superior to a waitlist control condition with moderate to large effects (range d = −0.62 to d = −0.92). Relative effects of different psychotherapeutic interventions on depressive symptoms were absent to small (range d = 0.01 to d = −0.30). Interpersonal therapy was significantly more effective than supportive therapy (d = −0.30, 95% credibility interval [CrI] [−0.54 to −0.05]). Moderator analysis showed that patient characteristics had no influence on treatment effects, but identified aspects of study quality and sample size as effect modifiers. Smaller effects were found in studies of at least moderate (Δd = 0.29 [−0.01 to 0.58]; p = 0.063) and large size (Δd = 0.33 [0.08 to 0.61]; p = 0.012) and those that had adequate outcome assessment (Δd = 0.38 [−0.06 to 0.87]; p = 0.100). Stepwise restriction of analyses by sample size showed robust effects for cognitive-behavioural therapy, interpersonal therapy, and problem-solving therapy (all d>0.46) compared to waitlist. Empirical evidence from large studies was unavailable or limited for other psychotherapeutic interventions.
Overall our results are consistent with the notion that different psychotherapeutic interventions for depression have comparable benefits. However, the robustness of the evidence varies considerably between different psychotherapeutic treatments.
Please see later in the article for the Editors' Summary
Depression is a very common condition. One in six people will experience depression at some time during their life. People who are depressed have recurrent feelings of sadness and hopelessness and might feel that life is no longer worth living. The condition can last for months and often includes physical symptoms such as headaches, sleeping problems, and weight gain or loss. Treatment of depression can include non-drug treatments (psychotherapy), antidepressant drugs, or a combination of the two. Especially for people with mild or intermediate depression, psychotherapy is often considered the preferred first option. Psychotherapy describes a range of different psychotherapies, and a number of established types of psychotherapies have all shown to work for at least some patients.
Why Was This Study Done?
While it is broadly accepted that psychotherapy can help people with depression, the question of which type of psychotherapy works best for most patients remains controversial. While many scientific studies have compared one psychotherapy with control conditions, there have been few studies that directly compared multiple treatments. Without such direct comparisons, it has been difficult to establish the respective merits of the different types of psychotherapy. Taking advantage of a recently developed method called “network meta-analysis,” the authors re-examine the evidence on seven different types of psychotherapy to see how well they have been shown to work and whether some work better than others.
What Did the Researchers Do and Find?
The researchers looked at seven different types of psychotherapy, which they defined as follows. “Interpersonal psychotherapy” is short and highly structured, using a manual to focus on interpersonal issues in depression. “Behavioral activation” raises the awareness of pleasant activities and seeks to increase positive interactions between the patient and his or her environment. “Cognitive behavioral therapy” focuses on a patient's current negative beliefs, evaluates how they affect current and future behavior, and attempts to restructure the beliefs and change the outlook. “Problem solving therapy” aims to define a patient's problems, propose multiple solutions for each problem, and then select, implement, and evaluate the best solution. “Psychodynamic therapy” focuses on past unresolved conflicts and relationships and the impact they have on a patient's current situation. In “social skills therapy,” patients are taught skills that help to build and maintain healthy relationships based on honesty and respect. “Supportive counseling” is a more general therapy that aims to get patients to talk about their experiences and emotions and to offer empathy without suggesting solutions or teaching new skills.
The researchers started with a systematic search of the medical literature for relevant studies. The search identified 198 articles that reported on such clinical trials. The trials included a total of 15,118 patients and compared one of the seven psychotherapies either with another one or with a common “control intervention”. In most cases, the control (no psychotherapy) was deferral of treatment by “wait-listing” patients or continuing “usual care.” With network meta-analysis they were able to summarize the results of all these trials in a meaningful way. They did this by integrating direct comparisons of several psychotherapies within the same trial (where those were available) with indirect comparisons across all trials (using no psychotherapy as a control intervention).
Based on the combined trial results, all seven psychotherapies tested were better than wait-listing or usual care, and the differences were moderate to large, meaning that the average person in the group that received therapy was better off than about half of the patients in the control group. When comparing the therapies with each other, the researchers saw small or no differences, meaning that none of them really stood out as much better or much worse than the others. They also found that the treatments worked equally well for different patient groups with depression (younger or older patients, or mothers who had depression after having given birth). Similarly, they saw no big differences when comparing individual with group therapy, or person-to-person with internet-based interactions between therapist and patient.
However, they did find that smaller and less rigorous studies generally found larger benefits of psychotherapies, and most of the studies included in the analysis were small. Only 36 of the studies had at least 50 patients who received the same treatment. When they restricted their analysis to those studies, the researchers still saw clear benefits of cognitive-behavioral therapy, interpersonal therapy, and problem-solving therapy, but not for the other four therapies.
What Do these Findings Mean?
Similar to earlier attempts to summarize and make sense of the many study results, this one finds benefits for all of the seven psychotherapies examined, and none of them stood as being much better than some or all others. The scientific support for being beneficial was stronger for some therapies, mostly because they had been tested more often and in larger studies.
Treatments with proven benefits still do not necessarily work for all patients, and which type of psychotherapy might work best for a particular patient likely depends on that individual. So overall this analysis suggests that patients with depression and their doctors should consider psychotherapies and explore which of the different types might be best suited for a particular patient.
The study also points to the need for further research. Whereas depression affects large numbers of people around the world, all of the trials identified were conducted in rich countries and Western societies. Trials in different settings are essential to inform treatment of patients worldwide. In addition, large high-quality studies should further explore the potential benefits of some of therapies for which less support currently exists. Where possible, future studies should compare psychotherapies with one another, because all of them have benefits, and it would not be ethical to withhold such beneficial treatment from patients.
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1001454.
The US National Institute of Mental Health provides information on all aspects of depression (in English and Spanish); information on psychotherapy includes information on its most common forms
The UK National Health Service Choices website also provides detailed information about depression and includes personal stories about depression
The UK nonprofit Mind provides information on depression, including an explanation of the most common psychotherapies in the UK
MedlinePlus provides links to other resources about depression (in English and Spanish)
The UK nonprofit healthtalkonline.org has a unique database of personal and patient experiences on depression