Source: http://www.medscape.com/viewarticle/855300
Veronica Hackethal, MD
December 02, 2015

Some mindfulness-based interventions significantly improve depression and anxiety related to a cancer diagnosis, according to a meta-analysis published in the November issue of Medicine.

"Our overall findings indicated that mindfulness-based therapy is effective for reducing anxiety and depression, whereas our subgroup analysis findings indicated that this may depend on the type of therapy administered and that the effect of treatment may not last longer than 12 weeks," wrote first author Mei-Fen Zhang, PhD, RN, of the School of Nursing at Sun Yat-sen University, in Guangzhou, China, and colleagues.

The diagnosis of cancer and its treatment (including side effects) can increase stress, anxiety, and depression, the researchers comment. Financial and family factors can add to the psychological burden of a cancer diagnosis. A variety of behavioral interventions have been developed to help patients cope with a cancer diagnosis, including cognitive-behavioral therapy, education, counseling, hypnosis, relaxation techniques, and mindfulness-based interventions.

Mindfulness-based interventions are rooted in the Buddhist idea of mindfulness, which refers to "intentional nonjudgmental awareness of present-moment experiences," according to background information in the article. Mindfulness-based interventions include mindfulness-based cognitive therapy, mindfulness-based stress reduction, and mindfulness-based art therapy.

In the study, researchers searched the Cochrane Library, EMBASE, and Google Scholar for studies published in English. They included randomized controlled trials of mindfulness-based interventions that evaluated changes in anxiety and depression in adult patients with cancer before and after the intervention in comparison with standard care. They also carried out subgroup analyses by cancer type, therapy type, and length of follow-up.

The analysis included seven studies with 469 participants in the intervention group and 419 persons in the control group. The most common studies involved breast cancer and interventions using mindfulness-based stress reduction and art therapy (5 of 7 studies). The length of interventions ranged from 7 to 8 weeks.

Compared with controls, mindfulness-based therapy resulted in significant changes from baseline in anxiety (pooled standardized mean difference [SMD], -0.75; 95% confidence interval [CI], 1.28 - 0.22; P= .005) and depression (SMD, -0.90, 95% CI, 1.53 - 0.26; P = .006).

In subgroup analyses, mindfulness-based art therapy resulted in significant improvements in anxiety (pooled SMD, -0.40; 95% CI, 0.66 - 0.14; P = .003) and depression (pooled SMD, -0.69; 95% CI, 0.954 - 0.426; P < .001). likewise, mindfulness-based cognitive therapy resulted in significant improvements in anxiety (pooled smd, -0.53; 95% ci, 0.92 - 0.15; p =".007)" and depression (pooled smd, -0.80; 95% ci, 1.19 - 0.40; p < .001).

No significant effects of treatment on anxiety were found on analyses by cancer type. Patients with breast cancer did not show significant improvements in depression with mindfulness-based stress reduction, though patients with other types of cancer did show improvements (pooled SMD, 0.90; 95% CI, 1.53 - 0.26; P = .006).

Anxiety and depression significantly improved in 12 weeks or less after initiation of the intervention (pooled SMD, -0.43; 95% CI, 0.58 - 0.28; P < .001; and pooled smd, -0.52; 95% ci, 0.75 - 0.29; p < .001, respectively), but the improvement did not persist after 12 weeks (pooled smd, -1.119; 95% ci, 2.63 - 0.393; p =".147).
Although in most studies, there was inadequate blinding of participants, there was no evidence of publication or design bias, according to the authors.

Studies varied in the type of mindfulness-based and control interventions, assessment of depression and anxiety, and types of cancer. In addition, subgroup analyses covered only a small number of studies and could not look at severity of anxiety/depression, time since diagnosis, and cancer stage. Studies lacked information on the effect of cancer treatment on depression and anxiety, so the meta-analysis could not evaluate these factors.

"[O]ur subgroup analyses, although clearly limited by the small number of eligible studies, suggest that the effect of mindfulness-based therapy may not persist over the long term and that some forms of mindfulness-based interventions may be less effective for relieving anxiety and depression," the authors conclude. "Clearly, further research is warranted to more definitively determine which forms of mindfulness-based therapy may be effective in this context and how best to optimize the persistence of benefits obtained."

The authors have disclosed no relevant financial relationships.

Medicine. 2015;94:e897.Full text