The Complete ‘Women Who Changed Science - And The World" Collection In Honor Of The 95th Women’s

Deconstructing the placebo response: Why does it work in treating depression?

In the past three decades, the power of placebos has gone through the roof in treating major depressive disorder. In clinical trials for treating depression over that period of time, researchers have reported significant increases in patient’s response rates to placebos — the simple sugar pills given to patients who think that it may be actual medication.

New research conducted by UCLA psychiatrists helps explain how placebos can have such a powerful effect on depression.

“In short,” said Andrew Leuchter, the study’s first author and a professor of psychiatry at the UCLA Semel Institute for Neuroscience and Human Behavior, “if you think a pill is going to work, it probably will.”

The UCLA researchers examined three forms of treatment. One was supportive care in which a therapist assessed the patient’s risk and symptoms, and provided emotional support and encouragement but refrained from providing solutions to the patient’s issues that might result in specific therapeutic effects. The other two treatments provided the same type of therapy, but patients also received either medication or placebos.

The researchers found that treatment that incorporating either type of pill — real medication or placebo — yielded better outcomes than supportive care alone. Further, the success of the placebo treatment was closely correlated to people’s expectations before they began treatment. Those who believed that medication was likely to help them were much more likely to respond to placebos. Their belief in the effectiveness of medication was not related to the likelihood of benefitting from medication, however.

“Our study indicates that belief in ‘the power of the pill’ uniquely drives the placebo response, while medications are likely to work regardless of patients’ belief in their effectiveness,” Leuchter said.

The study appears in the current online edition of the British Journal of Psychiatry.

At the beginning and end of the study, patients were asked to complete the Hamilton Rating Scale for Depression, giving researchers a quantitative assessment of how their depression levels changed during treatment. Those who received antidepressant medication and supportive care improved an average of 46 percent, patients who received placebos and supportive care improved an average of 36 percent, and those who received supportive care alone improved an average of just 5 percent.

“Interestingly, while we found that medication was more effective than placebo, the difference was modest,” Leuchter said.

The researchers also found that people who received supportive care alone were more likely to discontinue treatment early than those who received pills.

People with major depressive disorder have a persistent low mood, low self-esteem and a loss of pleasure in things they once enjoyed. The disorder can be disabling, and it can affect a person’s family, work or school life, sleeping and eating habits, and overall health.

In the double-blind study, 88 people ages 18 to 65 who had been diagnosed with depression were given eight weeks of treatment. Twenty received supportive care alone, 29 received a placebo with supportive care and 39 received actual medication with supportive care.

The researchers measured the patients’ expectations for how effective they thought medication and general treatment would be, as well as their impressions of the strength of their relationship with the supportive care provider.

“These results suggest a unique role for people’s expectations about their medication in engendering a placebo response,” Leuchter said. “Higher expectations of medication effectiveness predicted an improvement in placebo-treated subjects, and it’s important to note that people’s expectations about how effective a medication may be were already formed before they entered the trial.”

Leuchter said the research indicates that factors such as direct-to-consumer advertising may be shaping peoples’ attitudes about medication. “It may not be an accident that placebo response rates have soared at the same time the pharmaceutical companies are spending $10 billion a year on consumer advertising.”

(Image credit: © Chris Lamphear)

Better late than never!

This week’s entry: Hot Jupiters

http://www.space.com/32011-extremely-hot-and-fast-planets-seem-to-defy-logic.html

https://astrobites.org/2015/03/04/hot-jupiters-are-very-bad-neighbors/

It turns out that there’s actually a scientific reason behind why people don’t sleep soundly in an unfamiliar place. 

 According to a study conducted by Brown University, the first night that you sleep in a new environment the left hemisphere of the brain stays alert while the right hemisphere rests. The biological trait is thought to have allowed early humans to respond to nighttime threats. “When we’re sleeping in a new environment and we don’t know how many predators are around, it would make sense to keep half the brain more alert and more responsive to bumps in the night,” said Niels Rattenborg, who led the study. 

The evolutionary advantage this brain traits provides is probably less useful to modern humans — making us experience less restful sleep when we spend the night at a hotel or friend’s house, for example — but in the animal kingdom, this trait still helps marine mammals such as dolphins, whales, and seals respond to threats during their slumber.

FDA bans antibacterial soaps; “No scientific evidence” they’re safe, effective

Ban applies to soaps with any of 19 chemicals, including triclosan.

As Ars has reported previously, scientists have found that triclosan and other antimicrobial soaps have little benefit to consumers and may actually pose risks. These include bolstering antibiotic resistant microbes, giving opportunistic pathogens a leg up, and disrupting microbiomes. In its final ruling, issued Friday, the FDA seemed to agree. “Consumers may think antibacterial washes are more effective at preventing the spread of germs, but we have no scientific evidence that they are any better than plain soap and water,” Janet Woodcock, director of the FDA’s Center for Drug Evaluation and Research (CDER), said in a statement. “In fact, some data suggests that antibacterial ingredients may do more harm than good over the long-term.”

[…]

The ruling does not affect alcohol-based hand sanitizers or wipes, which the agency is reviewing separately. It also does not affect antiseptic products used in healthcare settings.

One of the best ways to get people to do something is to make it fun. A marketing campaign called ‘The Fun Theory’ found that when stairs next to an escalator were turned into giant, functional piano keys, the amount of people who took the stairs increased 66%, and when a trash can had sound effects that made it seem infinitely deep, people started picking up and throwing away litter just to hear it. Source

Perfect magnets

Now You Know (Source)

New theory explains how beta waves arise in the brain

Beta rhythms, or waves of brain activity with an approximately 20 Hz frequency, accompany vital fundamental behaviors such as attention, sensation and motion and are associated with some disorders such as Parkinson’s disease. Scientists have debated how the spontaneous waves emerge, and they have not yet determined whether the waves are just a byproduct of activity, or play a causal role in brain functions. Now in a new paper led by Brown University neuroscientists, they have a specific new mechanistic explanation of beta waves to consider.

The new theory, presented in the Proceedings of the National Academy of Sciences, is the product of several lines of evidence: external brainwave readings from human subjects, sophisticated computational simulations and detailed electrical recordings from two mammalian model organisms.

“A first step to understanding beta’s causal role in behavior or pathology, and how to manipulate it for optimal function, is to understand where it comes from at the cellular and circuit level,” said corresponding author Stephanie Jones, research associate professor of neuroscience at Brown University. “Our study combined several techniques to address this question and proposed a novel mechanism for spontaneous neocortical beta. This discovery suggests several possible mechanisms through which beta may impact function.”

Making waves

The team started by using external magnetoencephalography (MEG) sensors to observe beta waves in the human somatosensory cortex, which processes sense of touch, and the inferior frontal cortex, which is associated with higher cognition.

They closely analyzed the beta waves, finding they lasted at most a mere 150 milliseconds and had a characteristic wave shape, featuring a large, steep valley in the middle of the wave.

The question from there was what neural activity in the cortex could produce such waves. The team attempted to recreate the waves using a computer model of a cortical circuitry, made up of a multilayered cortical column that contained multiple cell types across different layers. Importantly, the model was designed to include a cell type called pyramidal neurons, whose activity is thought to dominate the human MEG recordings.

They found that they could closely replicate the shape of the beta waves in the model by delivering two kinds of excitatory synaptic stimulation to distinct layers in the cortical columns of cells: one that was weak and broad in duration to the lower layers, contacting spiny dendrites on the pyramidal neurons close to the cell body; and another that was stronger and briefer, lasting 50 milliseconds (i.e., one beta period), to the upper layers, contacting dendrites farther away from the cell body. The strong distal drive created the valley in the waveform that determined the beta frequency.

Meanwhile they tried to model other hypotheses about how beta waves emerge, but found those unsuccessful.

With a model of what to look for, the team then tested it by looking for a real biological correlate of it in two animal models. The team analyzed measurements in the cortex of mice and rhesus macaques and found direct confirmation that this kind of stimulation and response occurred across the cortical layers in the animal models.

“The ultimate test of the model predictions is to record the electrical signals inside the brain,” Jones said. “These recordings supported our model predictions.”

Beta in the brain

Neither the computer models nor the measurements traced the source of the excitatory synaptic stimulations that drive the pyramidal neurons to produce the beta waves, but Jones and her co-authors posit that they likely come from the thalamus, deeper in the brain. Projections from the thalamus happen to be in exactly the right places needed to deliver signals to the right positions on the dendrites of pyramidal neurons in the cortex. The thalamus is also known to send out bursts of activity that last 50 milliseconds, as predicted by their theory.

With a new biophysical theory of how the waves emerge, the researchers hope the field can now investigate whether beta rhythms affect or merely reflect behavior and disease. Jones’s team in collaboration with Professor of Neuroscience Christopher Moore at Brown is now testing predictions from the theory that beta may decrease sensory or motor information processing functions in the brain. New hypotheses are that the inputs that create beta may also stimulate inhibitory neurons in the top layers of the cortex, or that they may may saturate the activity of the pyramidal neurons, thereby reducing their ability to process information; or that the thalamic bursts that give rise to beta occupy the thalamus to the point where it doesn’t pass information along to the cortex.

Figuring this out could lead to new therapies based on manipulating beta, Jones said.

“An active and growing field of neuroscience research is trying to manipulate brain rhythms for optimal function with stimulation techniques,” she said. “We hope that our novel finding on the neural origin of beta will help guide research to manipulate beta, and possibly other rhythms, for improved function in sensorimotor pathologies.”

Life from the perspective of colour blind people 

Deuteranomalia: This is caused by reduced sensitivity to green light. Deutan color vision deficiencies are by far the most common forms of color blindness. This subtype of red-green color blindness is found in about 6% of the male population, mostly in its mild form deuteranomaly.

Protanopia: Caused by a reduced sensitivity to red light due to either defective or a lack of long -wavelength cones (red cones). Some scientists estimate that being a protan is associated with a risk of a road accident equivalent to having a blood alcohol level of between 0.05 and 0.08 per cent.

Tritanopia:  People affected by tritan color blindness confuse blue with green and yellow with violet.  This is due to a defective short-wavelength cone (blue cone). Whilst  Protanopia and Deuteranomalia are significantly more common in men, tritanopia affects both sexes in equal amounts.

Monochromacy: Only around 0.00003% of the world’s population suffers from total color blindness, where everything is seen in black and white.