Friday, December 24, 2010

Placebos Work -- Even Without Deception


For most of us, the "placebo effect" is synonymous with the power of positive thinking; it works because you believe you're taking a real drug. But a new study rattles this assumption.

Researchers at Harvard Medical School's Osher Research Center and Beth Israel Deaconess Medical Center (BIDMC) have found that placebos work even when administered without the seemingly requisite deception.

The study is published December 22 in PLoS ONE.

Placebos -- or dummy pills -- are typically used in clinical trials as controls for potential new medications. Even though they contain no active ingredients, patients often respond to them. In fact, data on placebos is so compelling that many American physicians (one study estimates 50 percent) secretly give placebos to unsuspecting patients.

Because such "deception" is ethically questionable, HMS associate professor of medicine Ted Kaptchuk teamed up with colleagues at BIDMC to explore whether or not the power of placebos can be harnessed honestly and respectfully.

To do this, 80 patients suffering from irritable bowel syndrome (IBS) were divided into two groups: one group, the controls, received no treatment, while the other group received a regimen of placebos -- honestly described as "like sugar pills" -- which they were instructed to take twice daily.

"Not only did we make it absolutely clear that these pills had no active ingredient and were made from inert substances, but we actually had 'placebo' printed on the bottle," says Kaptchuk. "We told the patients that they didn't have to even believe in the placebo effect. Just take the pills."

For a three-week period, the patients were monitored. By the end of the trial, nearly twice as many patients treated with the placebo reported adequate symptom relief as compared to the control group (59 percent vs. 35 percent). Also, on other outcome measures, patients taking the placebo doubled their rates of improvement to a degree roughly equivalent to the effects of the most powerful IBS medications.

"I didn't think it would work," says senior author Anthony Lembo, HMS associate professor of medicine at BIDMC and an expert on IBS. "I felt awkward asking patients to literally take a placebo. But to my surprise, it seemed to work for many of them."

The authors caution that this study is small and limited in scope and simply opens the door to the notion that placebos are effective even for the fully informed patient -- a hypothesis that will need to be confirmed in larger trials.

"Nevertheless," says Kaptchuk, "these findings suggest that rather than mere positive thinking, there may be significant benefit to the very performance of medical ritual. I'm excited about studying this further. Placebo may work even if patients knows it is a placebo."

This study was funded by the National Center for Complementary and Alternative Medicine and Osher Research Center, Harvard Medical School.

Wednesday, December 8, 2010

Mindfulness meditation found to be as effective as antidepressants to prevent depression relapse


A new study from the Centre for Addiction and Mental Health (CAMH) has found that mindfulness-based cognitive therapy--using meditation—provides equivalent protection against depressive relapse as traditional antidepressant medication.

The study published in the current issue of the Archives of General Psychiatry compared the effectiveness of pharmacotherapy with mindfulness-based cognitive therapy (MBCT) by studying people who were initially treated with an antidepressant and then, either stopped taking the medication in order to receive MBCT, or continued taking medication for 18 months.

"With the growing recognition that major depression is a recurrent disorder, patients need treatment options for preventing depression from returning to their lives." said Dr. Zindel Segal, Head of the Cognitive Behaviour Therapy Clinic in the Clinical Research Department at CAMH.

"Data from the community suggest that many depressed patients discontinue antidepressant medication far too soon, either because of side effect burden, or an unwillingness to take medicine for years. Mindfulness-based cognitive therapy is a non pharmacological approach that teaches skills in emotion regulation so that patients can monitor possible relapse triggers as well as adopt lifestyle changes conducive to sustaining mood balance.

Study participants who were diagnosed with major depressive disorder were all treated with an antidepressant until their symptoms remitted. They were then randomly assigned to come off their medication and receive MBCT; come off their medication and receive a placebo; or stay on their medication. The novelty of this design permits comparing the effectiveness of sequencing pharmacological and psychological treatments versus maintaining the same treatment – antidepressants - over time

Participants in MBCT attended 8 weekly group sessions and practiced mindfulness as part of daily homework assignments. Clinical assessments were conducted at regular intervals, and over an 18 month period, relapse rates for patients in the MBCT group did not differ from patients receiving antidepressants (both in the 30% range), whereas patients receiving placebo relapsed at a significantly higher rate (70%).

"The real world implications of these findings bear directly on the front line treatment of depression. For that sizeable group of patients who are unwilling or unable to tolerate maintenance antidepressant treatment, MBCT offers equal protection from relapse,".said Dr. Zindel Segal. "Sequential intervention-- offering pharmacological and psychological interventions-- may keep more patients in treatment and thereby reduce the high risk of recurrence that is characteristic of this disorder.

What Zen meditators don't think about won't hurt them


Zen meditation has many health benefits, including a reduced sensitivity to pain. According to new research from the Université de Montréal, meditators do feel pain but they simply don't dwell on it as much. These findings, published in the month's issue of Pain, may have implications for chronic pain sufferers, such as those with arthritis, back pain or cancer.

“Our previous research found that Zen meditators have lower pain sensitivity. The aim of the current study was to determine how they are achieving this,” says senior author Pierre Rainville, researcher at the Université de Montréal and the Institut universitaire de gériatrie de Montréal. “Using functional magnetic resonance imaging, we demonstrated that although the meditators were aware of the pain, this sensation wasn't processed in the part of their brains responsible for appraisal, reasoning or memory formation. We think that they feel the sensations, but cut the process short, refraining from interpretation or labelling of the stimuli as painful.”

Training the brain
Rainville and his colleagues compared the response of 13 Zen meditators to 13 non-meditators to a painful heat stimulus. Pain perception was measured and compared with functional MRI data. The most experienced Zen practitioners showed lower pain responses and decreased activity in the brain areas responsible for cognition, emotion and memory (the prefrontal cortex, amygdala and hippocampus). In addition, there was a decrease in the communication between a part of the brain that senses the pain and the prefrontal cortex.

“Our findings lead to new insights into mind/brain function,” says first author, Joshua Grant, a doctoral student at the Université de Montréal. “These results challenge current concepts of mental control, which is thought to be achieved by increasing cognitive activity or effort. Instead, we suggest it is possible to self-regulate in a more passive manner, by ‘turning off' certain areas of the brain, which in this case are normally involved in processing pain.”

“The results suggest that Zen meditators may have a training-related ability to disengage some higher-order brain processes, while still experiencing the stimulus,” says Rainville. “Such an ability could have widespread and profound implications for pain and emotion regulation and cognitive control. This behaviour is consistent with the mindset of Zen and with the notion of mindfulness.”

About the Study:
“A non-elaborative mental stance and decoupling of executive and pain-related cortices predicts low pain sensitivity in Zen meditators” was authored by Joshua A. Grant, Jérôme Courtemanche and Pierre Rainville from the Université de Montréal.

Partners in research:
This study was funded by a grant from the Mind and Life Institute with support for Joshua Grant provided by the Canadian Institutes of Health Research.