New Study Reveals Stagnant Depression Outcomes in Clinical Trials Over Time

A new meta-analysis uncovers the grim reality that despite a flurry of research on psychological treatments, response rates in routine depression care remain low and unchanged over the years.

In an era of advanced psychological treatments for depression, one might anticipate notable improvements in patient outcomes. However, a recent meta-analysis led by Pim Cuijpers and colleagues from the Amsterdam Public Health Research Institute tells a different story. Published in the Journal of Affective Disorders, the study examines the response and remission rates of routine mental health care over the years, revealing persistently low outcomes.

The study analyzed data from 125 randomized controlled trials (RCTs) involving 8,542 participants, comparing care-as-usual (CAU) control groups across various healthcare settings, including primary care, specialized mental health care, perinatal care, and general medical care. Shockingly, the overall response rate was just 22%, with primary care showing a slightly higher rate of 27%. Despite the increasing availability of evidence-based treatments, the research found no significant improvement in response or remission rates over time.

The authors write,

“It is very important to examine what the exact reasons are for the stable response rates over time and how this rate can be improved. It makes little sense to conduct hundreds of randomized trials on psychological treatments when they do not lead to better routine practice.”

The results of randomized controlled trials (RCTs) often fail to translate effectively to clinical practice due to several inherent limitations. RCTs are typically conducted over short durations with homogenous client populations that do not reflect the diversity and complexity of real-world patients. Researchers conducting these trials often have allegiance effects, where their belief in the efficacy of the treatment may bias the outcomes.

In addition, the manualization of therapy—a rigid protocol developed for consistency in RCTs—can be detrimental in clinical settings. This approach diverts resources from more flexible, long-term therapies that offer depth and insight, potentially worsening outcomes. Such therapies are crucial for addressing patients’ nuanced and varied needs, fostering genuine therapeutic relationships, and allowing for the adaptation of techniques to individual circumstances. The manualized, one-size-fits-all treatments often fail to account for these factors, leading to less effective care in practice.

Despite hundreds of randomized controlled trials (RCTs) demonstrating the effectiveness of psychological treatments like psychotherapy for depression, it remains unclear whether these treatments are being integrated into routine care. Moreover, there is insufficient research on the long-term outcomes of routine care. Thus, the authors examined the outcomes of usual-care control groups in RCTs.

They assume that when an RCT concludes treatment is effective, it would be implemented into routine care, therefore improving outcomes of usual care control groups over time, especially since a growing number of evidence-based therapies have become available.

The authors used an existing meta-analytic database of RCTs on psychotherapies for depression and selected trials where a psychological treatment of depression (defined as meeting criteria for a depressive disorder) was compared with a care-as-usual control group in one of the following four areas of health care: primary care, specialized mental health care, perinatal care, and general medical care.

The primary outcome was the treatment response rate, which they defined as a 50% symptom reduction. Additionally, they examined remission rates by comparing scores to the Hamilton Rating Scale for Depression. They calculated pre-post Standardized Mean Differences (SMDs), and sensitivity analyses were conducted.

After examining 33,039 records, 125 care as usual (CAU) control groups from RCTs were included, comprising 8542 adult participants in Europe and North America.

The overall response rate for all care-as-usual conditions was 0.22. There were notable differences across the four areas, with primary care having the highest rate at 0.27. Additionally, they found low response and remission rates for usual care, concluding almost 80% of patients in routine care do not respond, and only one in six or seven patients remit across the different routine care settings. The sensitivity analyses supported the main findings.

In sum, they found “hardly any indications that the outcomes of usual care control groups have improved over the years. In almost all analyses, we found that response rates, remission rates, and SMDs have remained stable over the years.”

The authors’ results were different from what they expected, and they offer two possible explanations. First, they suggest that evidence-based interventions may not be as effective when applied in routine settings, possibly because patients in routine care are not sufficiently included in RCTs. Second, they suggest that treatments found to be effective in randomized controlled trials are not disseminated, and if they are, not in the right way.

The authors note the study’s limitations, such as the relatively small number of studies in each category, most studies suffering from at least some risk of bias, and routine practices in care settings differing across regions.

However, the authors still confidently conclude that outcomes of usual care have not improved over time and end by calling for “the need for more research on how implementation and dissemination of effective interventions in routine care can be improved.”

This study contributes to a growing body of literature that reveals current treatment options are not sufficient in responding to depression and can have negative side effects. Additionally, not only is this study important for recognizing the need for implementing and disseminating adequate interventions, but it also calls into question current diagnostic methods and research approaches for depression, leaving room to ponder alternative etiologies and consider social and cultural factors that may influence depression.

 

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Cuijpers, P., Miguel, C., Harrer, M., Ciharova, M., & Karyotaki, E. (2024). The outcomes of mental health care for depression over time: A meta-regression analysis of response rates in usual care. Journal of Affective Disorders, 358, 89–96. https://doi.org/10.1016/j.jad.2024.05.019 (Link)