Those delicious chills you get as your favorite piece of music reaches its climax? They’re the result of a glorious spike of dopamine in your brain–that’s the same neurotransmitter that’s involved in reward, motivation, and addiction.

In a nifty series of experiments published in Nature Neuroscience, researchers determined that music provokes floods of dopamine in music lovers. Study coauthor Valorie Salimpoor notes that dopamine has long been known to play a role in more physical activities like taking drugs and having sex, but this research highlights its role in other aspects of our lives.

“It is amazing that we can release dopamine in anticipation of something abstract, complex and not concrete,” Salimpoor said. “This is the first study to show that dopamine can be released in response to an aesthetic stimulus.” [Discovery News]

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A new study out this week has rekindled an old economics fight: When countries get richer, do they get happier?

For Richard Easterlin, the answer has always been “no.” He became famous in economics circles beginning in the 1970s for articulating his namesake idea, the “Easterlin paradox.” He found that when you compare rich countries to poor countries, the people in the wealthy nations were more satisfied. But when a country’s economic position improved over time, the people in that country didn’t get happier.

“If you look across countries and compare happiness and GDP [gross domestic product] per capita, you find that the higher the country’s income, the more likely it is to be happier,” Easterlin said. “So the expectation based on point-in-time data is if income goes up, then happiness will go up. The paradox is, when you look at change over time, that doesn’t happen.” [LiveScience]

Now Easterlin is back with a new study in the Proceedings of the National Academy of Sciences, one that extends his argument to even more countries.

The new study, Easterlin said, is the broadest finding about the paradox so far. The researchers gathered between 10 and 34 years of happiness data from 17 Latin American countries, 17 developed countries, 11 Eastern European countries transitioning from socialism to capitalism and nine-less developed countries. They found no relationship between economic growth and happiness in any case. Even in a country like China, the researchers wrote, where per capita income has doubled in 10 years, happiness levels haven’t budged. South Korea and Chile have shown similarly astronomical economic growth with no increase in satisfaction. [LiveScience]

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Since its emergence in the early 1980s, the drug isotretinoin—used to treat severe acne and sold under a host of different brand names—has been subject to controversy over whether it increases the incidence of suicide attempts in those who take it. But sorting out whether the drug, the acne itself, or some other factor is driving increased suicide risk is quite difficult.

So for a study out in the British Medical Journal, a team of researchers in Sweden looked at a deluge of data for 5,756 people who took the drug. Their conclusion: Severe acne patients who took isotretinoin had an increased risk for suicide attempts both before and after taking it, so they can’t definitively link isotretinoin to suicide.

The drug, perhaps best known as the pharmaceutical company Roche’s Accutane, has been embraced by dermatologists and their suffering patients, but has also been dogged by controversy for its side effects.

While powerful at clearing acne, the drug has been linked to birth defects if taken during pregnancy and has also been suspected of causing mental side effects, although Roche has vigorously defended personal injury claims in this area. [Reuters]

Anders Sundstrom led the current research, which seems to support the theory that the pharmaceutical isn’t a threat to mental health. Said Sundstrom:

“The underlying condition of acne is a more important factor for suicide attempts. We are not certain the drug adds anything.” [BBC News]

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In many high-tech parts of the world, iPhones are what people turn to when their minds wander from what they were supposed to be doing. For a study in this week’s Science, however, researchers turned the tables on these people, using the iPhone as a tool to study the wandering mind. Matthew Killingsworth and Daniel Gilbert found that the minds wanders a lot (no surprise there), but also that daydreaming could make people unhappier.

Their app, called Track Your Happiness, takes advantage of the iPhone’s unparalleled ability to butt into its owner’s life.

iPhone users, aged 18 to 88, signed up for a Web application that contacted study them at random times during their days to ask a simple set of questions: How happy were they at the moment? What were they doing? Were they thinking about something other than what the task at hand, and if so, were they thinking of something pleasant, neutral, or negative? [Boston Globe]

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According to a new study out in Science Translational Medicine, treating depressed mice with gene therapy in the brain to bolster a protein connected to the neurotransmitter serotonin can make those depressive symptoms dissipate.

Here’s the gist: The gene in question creates a protein called p11 that help carry serotonin receptors up to the surface of a brain cell where they can receive signals from other brain cells. Poor serotonin signaling may be one of the major drivers behind depression, and a dearth of p11 could worsen the problem, according to study author Michael Kaplitt.

“In the absence of p11, a neuron can produce all the serotonin receptors it needs, but they will not be transported to the cell surface,” said Kaplitt. [AFP]

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Ketamine for bipolar disorder. LSD for depression. It’s been a busy month for psychedelic drugs in the laboratory, as several studies showed that these drugs typically used recreationally—and illegally—affect the brain in ways that could make them useful for treating mental illness.

First came a small study in the Archives of General Psychiatry that we covered earlier this month, in which scientists tested 18 patients who on average had tried seven kinds of drugs to treat their bipolar disorder. When the researchers gave them small doses of ketamine—a powerful anesthetic that people use recreationally for the hallucinogenic side effects—the patients’ depressive symptoms lessened within a matter of minutes.

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Recreational drug users call it “Special K.” Large, frequent doses of the anesthetic ketamine can give users vivid hallucinations, but a recently published study hints that the drug may have a medicinal use: temporarily treating depression brought on by bipolar disorder.

The small, proof-of-concept study appears in the journal Archives of General Psychiatry. National Institutes of Health researchers randomly gave 18 depressed patients ketamine or a placebo on two different days, two weeks apart. They used a much smaller dose of the drug than the amount used for recreation or anesthesia, but within 40 minutes 71 percent of the patients who received ketamine showed a significant improvement in mood, which lasted for three days, as measured using a psychiatric depression rating scale.

The quick response time is unusual for the drugs typically used to treat bipolar disorder’s depression, such as lithium or antidepressants like Prozac, and many of the study’s patients had failed to respond to other treatments. On average, the study participants had tried seven antidepressants and 55 percent of participants had failed to respond positively to the extreme measures of electroconvulsive therapy (ECT)–seizures brought on by electrical current. Ketamine’s apparent success may have to do with the neurotransmitter, glutamate:

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Scientists have long suspected that a link exists between mood and chocolate, as studies (done primarily with women) have suggested that eating a chocolate bar temporarily banished the blues. Now a study has brought new complexity to the issue with its finding that depressed people consume larger amounts of chocolate. But researchers are no closer to figuring out which factor is the cause and which is the effect: Do glum people reach for a Hershey bar to lift their spirits, or is the chocolate actually bringing them down?

For this study, researchers at the University of California studied 931 men and women who weren’t on antidepressants and quizzed them on their chocolate-chomping habits. Then, using a standard screening survey, they assessed the volunteers for symptoms of depression. The scientists found that those who were the most blue consumed the most chocolate.

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Evaluating the happiness of an entire society is tricky–after all, the traditional survey-based method of collecting data doesn’t work for such a huge population. But now scientists say they have come up with a way to quantify the well-being of a society: by analyzing song lyrics and blog posts for emotionally charged words, according to a study published in the Journal of Happiness Studies. Among their findings, researchers determined that bloggers in their 50s and 60s are most content, and that popular music has become increasingly less happy since the 1960s.

To evaluate the overall happiness of the public, researchers pulled data from nearly two-and-a-half million blogs and 230,000 song lyrics. With the aid of their own computers, the researchers scanned the texts for more than 1000 emotionally charged words that a 1999 psychology study had ranked on a scale from 1 (miserable) to 9 (ecstatic). “Triumphant” and “love” topped the list with average scores greater than 8.7, whereas “disgusted” was one of the lowest at 2.45. The researchers then calculated an average happiness score for each text based on the words’ scores and frequencies [ScienceNOW Daily News]. They found that although certain days of the year always show fluctuations in the blog world (Christmas and Valentine’s Day show a spike in happiness, while September 11 shows a dip in well-being), overall happiness among the bloggers since 2005 has increased about 4 percent.

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For six years, psychiatrists thought they had found a genetic clue as to what makes some people more prone to depression when they’re hit with an emotional blow: a single gene. A 2003 study created a sensation among scientists and the public because it offered the first specific, plausible explanation of why some people bounce back after a stressful life event while others plunge into lasting despair [The New York Times]. But now a broader analysis of 14 studies has found no link between the gene and the risk of depression, and researchers argue that the 2003 findings were prematurely heralded as a breakthrough. “I think what happened is that people who’d been working in this field for so long were desperate to have any solid finding” [The New York Times], says Kathleen R. Merikangas, one of the authors of the new study.

The so-called “depression gene” that researchers focused on in the 2003 study helps regulate levels of serotonin, a brain chemical that plays a major role in depression and is a key target of antidepressant drugs. Researchers … found from a long-term study of 847 people in New Zealand that those with a short version, or allele, of the serotonin transporter gene were more likely to become depressed by adverse life events than were those with only long alleles [ScienceNOW Daily News].

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Inserting a “pacemaker” into the brain to emit regular pulses of electricity and quell disordered neural activity may sound like a therapy of last resort, but if current experiments show beneficial results the brain surgery may one day be commonplace. But some scientists are cautioning that research on so-called deep brain stimulation may be pressing ahead too quickly, and warn that long-term effects of the surgery are not yet clear.

A growing number of psychiatric researchers are testing the method’s effectiveness on a host of psychiatric disorders. Until recently, deep brain stimulation was approved in the U.S. only to treat certain movement disorders, primarily those of Parkinson’s disease, for which it diminishes tremors and rigidity and improves mobility. To date, more than 60,000 patients worldwide have had the devices implanted [Los Angeles Times]. But now large clinical trials are in the works that will test the use of deep brain stimulation for obsessive compulsive disorder, epilepsy, and depression. Smaller experiments are beginning to assess the therapy’s effectiveness on a wide range of disorders including anorexia, drug addiction, obesity, traumatic brain injury, and Alzheimer’s.

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Tumors may physically trigger depression by producing chemicals that induce negative mood swings, according to a new study. The research, conducted in rats, allowed for the isolation of “just the physiological effects of the tumors from the psychological effects…. The tumors themselves are sufficient to induce depression” [The Scientist], says lead researcher Leah Pyter.

The new study, published in the Proceedings of the National Academy of Sciences, showed first that rats who had cancer exhibited several behavioral symptoms associated with depression. The researchers gave a forced swimming test to 100 rats, some healthy and some with cancer, and found that the sick rats did not try as hard to escape—a behavior similar to that seen in humans with depression. The sick rats were also less interested in sugar water, which is the the clear preference for healthy rats.

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The Saturday Night Live character who famously recited the mantra: “I’m good enough, I’m smart enough, and doggone it, people like me” may have been setting a valuable example for schoolkids. A new study asked middle school students to do short, self-affirming writing exercises, and found that the simple task boosted the grades of some students for two years afterward. The students who benefited most were blacks who were doing poorly, the study found; the exercises made no difference for white students, or for black ones who were already doing well [The New York Times].

The result is exciting, lead researcher Geoffrey Cohen says, because it suggests that even modest interventions, when done early, can interrupt a downward achievement spiral. “Small changes to an individual’s psychological state can have surprisingly large effect over time if they alter the angle of people’s performance trajectory,” he said, adding that the early benefit is compounded over time [Reuters].

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People with a family history of depression have an altered brain anatomy, a new study says, even if they themselves have never experienced clinical depression. Brain scans showed a 28-percent thinning in the right cortex — the outer layer of the brain — in people who had a family history of depression compared with people who did not. “The difference was so great that at first we almost didn’t believe it. But we checked and re-checked all of our data, and we looked for all possible alternative explanations, and still the difference was there” [Reuters], said study coauthor Bradley Peterson.

Researchers scanned the brains of 131 individuals ranging in age from 6 to 54, about half of whom came from families with a history of depression. The team was looking specifically for abnormalities in the brain that could signal a predisposition to depression, rather than changes that may be caused by the disease [Reuters]. The cortical thinning seems to fit the definition as a warning flag. Says Peterson: “That’s what is so extraordinary. You’re seeing it two generations later, and you’re seeing it in both children and adults…. And it’s present even if those offspring themselves have not yet become ill” [The New York Times].

The cerebral cortex is largely responsible for reasoning, planning, and mood, and researchers suggest that its thinning may interfere with a person’s ability to interpret social and emotional cues from others. Interestingly, not all of the subjects with depressed family members showed thinning on both sides of their cortices; it was primarily those with thinning in the left hemisphere who had actually developed depression.

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While that headline may overstate the case slightly for comic effect, researchers say the gist of it is true: Stroke patients with impaired vision who listened to their favorite music showed vastly improved visual processing. Says lead researcher David Soto: “One of the patients chose Kenny Rogers, another Frank Sinatra and the third a country rock band. It’s not a particular kind of music that’s important, as long as the patient enjoys it” [Daily Mail].

Participants in Soto’s study had suffered lesions to their brains’ parietal cortex, a region central to visual and spatial processing. This left them with a condition called visual neglect, in which people lose half their spatial awareness. Victims will sometimes eat food from only one side of their plate, shave one side of their faces, or — as tested in the study — fail to perceive visual prompts on one side of a computer screen [Wired].  

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