In Brief

  • Woman drinking coffeeDrinking coffee could lower women's risk for depression, suggest data from the Harvard Nurses' Health Study, a longitudinal study of 50,793 nurses that includes self-reports on caffeine consumption. Women in the study who drank four cups of caffeinated coffee a day were 20 percent less likely to be diagnosed with depression or prescribed antidepressants over a 10-year period than women who drank one cup of coffee or less a week. While more research is needed to determine whether coffee drinking may contribute to depression treatment or prevention, say the researchers, the findings support a possible protective effect and are consistent with an earlier study that found suicide risk is lower among people with higher coffee consumption. (Archives of Internal Medicine, Sept. 26)
  • Prolonged exposure therapy and cognitive therapy are similarly effective at reducing post-traumatic stress disorder symptoms, finds research from Hadassah University Hospital in Jerusalem. The researchers found that patients who had either of those therapies immediately following a traumatic event showed fewer symptoms of PTSD at a five-month follow-up than patients who took antidepressants or a placebo. Patients who started prolonged exposure therapy five months after their trauma reduced their PTSD symptoms as much as patients who began therapy immediately after their trauma. (Archives of General Psychiatry, Oct. 3)
  • People may use marijuana to cope with the effects of trauma, according to a study led by Florida State University researchers. The researchers analyzed data from 5,672 respondents to the National Comorbidity Survey and found that people who had symptoms of post-traumatic stress disorder (PTSD) were more likely to have used cannabis, and more likely to use it daily. This correlation stood up even when researchers accounted for demographics and the presence of other disorders. This and related findings suggest that people may self-medicate with marijuana to control symptoms of PTSD, such as sleeplessness and hypervigilance. (Psychology of Addictive Behaviors, September)
  • Infant stressStress in the neonatal intensive care unit may slow the growth of premature infants' brains, according to researchers at Washington University in St. Louis. The researchers observed 44 infants in the neonatal intensive care unit born before 30 weeks of pregnancy. Using magnetic resonance imaging and neurobehavioral examinations, the researchers found that infants who experienced a high number of stressors — such as intubation and even diaper changes — in their first two weeks had decreased frontal and parietal brain width and altered brain microstructure and functional connectivity in the temporal lobes. These changes are often associated with neurodevelopmental problems later in childhood. (Annals of Neurology, Oct. 4)
  • Electric stimulation of a specific brain region produces new brain cells that enhance memory in mice, according to researchers at The Hospital for Sick Children in Toronto. In the study, researchers used deep brain stimulation for one hour on the mices' entorhinal cortices, a brain region that communicates with the hippocampus. They found that the stimulation led to a twofold increase in new cells in the hippocampus that lasted for about one week. The cells developed normally and made connections with other nearby brain cells. The findings may lead to interventions for treating people with memory disorders, the study authors say. (Journal of Neuroscience, Sept. 21)
  • Chickadees, pigeons and humans show similar patterns of chord perception, according to a study by researchers at the University of Alberta. In the study, the birds and humans made fewer mistakes when distinguishing between major and augmented chords than when comparing major and minor chords. The results suggest that all hearing animals may share the basic machinery of harmonic perception. (Journal of Comparative Psychology®, September)
  • Conflict between spouses stays stable over the course of a marriage, according to a study led by researchers at Ohio State University. The study of nearly 1,000 couples found that those who clashed in the 1980s were still fighting 20 years later, while harmonious couples tended to stay that way. The secret of the low-conflict-couples' success may have been their tendency to make decisions collaboratively, the researchers posit. (Journal of Family Issues, September)
  • Born optimists may be able to maintain their rosy outlooks because of a glitch in how they process negative information, according to a study led by a psychologist at University College London. The researchers gave 19 participants a quiz designed to measure optimism. Then they asked the participants to estimate the likelihood that they would experience a bad event, such as a car theft. The researchers then told the participants the real likelihood of the event. Using fMRI, the researchers found that when this news was good — the bad event was less likely than the participants had thought — the participants changed their estimates to be even more positive, and showed correlated activity in their frontal lobe as they made the change. But when the news was bad, the more optimistic participants didn't tend to revise their estimates to be more in line with the truth, and the activity in their frontal lobes suggested that they were not processing the bad news as efficiently as their less optimistic peers. (Nature Neuroscience, Oct. 9)
  • A newly identified protein helps keep the brain from forming memories of stressful events, according to researchers at the University of Leicester. The protein, which is encoded by the lipocalin-2 gene, affects neurons' dendritic spines. When those spines are immature, they are long and thin and can change their connections to help people learn and form new memories. When the spines mature, they become short and mushroom shaped, their connections stabilize and the memory is set. The researchers found that when they added the protein to neurons in the lab, the neurons started to lose those mushroom-shaped memory spines. They also found that mice with a faulty lipocalin-2 gene were more anxious than other mice. The researchers say the newly discovered protein is a step toward understanding the molecular causes of stress-related disorders. (PNAS, Oct. 3)
  • Using "magic mushrooms" can have a long-term effect on some people's personalities, making them more open, curious and creative, according to Johns Hopkins University researchers. In a study of 51 adults, they found that people who had a mystical experience while taking psilocybin, the active ingredient in hallucinogenic mushrooms, tested higher on scores of openness — a personality trait related to creativity and curiosity — than they had before they took the drugs. The change was still in place at a follow-up test one year later, a surprise considering that many researchers consider personality relatively fixed in adulthood. (Journal of Psychopharmacology, Sept. 28)
  • Child looking at pineconesChildren as young as 3 are likely to say that objects made by humans have owners, but that natural objects such as pinecones and seashells do not, according to a study led by researchers at Waterloo University in Canada. The finding provides the first evidence about how children judge the ownership of things based on whether those things are artificial or natural, the researchers say. (Developmental Psychology®, Sept. 19)