In brief

• Families with lower levels of education and income are less likely to enforce regular bedtimes for children, a pattern that may contribute to learning problems, a lack of school readiness and childhood obesity, finds research published online in September in the Journal of Developmental & Behavioral Pediatrics. Using data from a nationwide sample of 3,217 children followed from birth to age 3, researchers led by Stony Brook University Medical Center professor Lauren Hale, PhD, also found that black and Hispanic children have later bedtimes than white children and are about 25 percent less likely to have regular bedtimes and more than a third less likely to have a standard bedtime hygiene routine.

• Psychotherapy appears to ease depression symptoms and reduce systemic inflammation among newly diagnosed breast cancer patients, according to research in September's Psychosomatic Medicine (Vol. 71, No. 7). Over a year, patients in the intervention group—which included weekly and then monthly therapy sessions focused on reducing stress and enhancing coping abilities—showed significant declines in symptoms of depression, fatigue, pain and markers of inflammation in cancer cells as compared with the assessment-only control group, which showed no improvement in depression or inflammation. The results, says Ohio State psychologist Lisa Thornton, PhD, indicate that mental health professionals need to be more involved in evaluating and monitoring people after a cancer diagnosis.

• Excessive exercising can be as addictive as heroin, suggests a study in August's Behavioral Neuroscience (Vol. 123, No. 4). Led by Tufts University psychologist Robin Kanarek, PhD, researchers allowed 44 male and 40 female rats either to run on exercise wheels or remain inactive for several weeks; the rats then received naloxone, a medicine for heroin overdose that produces immediate withdrawal symptoms. The active rats trembled, writhed and displayed teeth chattering and drooping eyelids—withdrawal symptoms similar to those seen in narcotics addicts.

• For every 10-point increase in a person's diastolic blood pressure reading, their odds of experiencing cognitive problems increase by 7 percent, finds a nationwide University of Alabama at Birmingham study of 20,000 people age 45 and older, in Neurology (Vol. 73, No. 8). In response to the research, the National Institutes of Health plans to organize a large clinical trial to evaluate whether aggressive hypertension treatment through diet, drugs and exercise can decrease cognitive decline.

• New research offers clues as to why most adults don't remember the details of events that happened to them before age 4. In the study, Seton Hall University psychologist Marianne E. Lloyd, PhD, and colleagues showed children age 4 and 6 objects, backgrounds and object and background combinations—for example, a cat on a green background or a cup on a red background—to remember. The researchers found that the younger children were good at remembering individual items they'd seen before, but not as good at remembering how items occurred together, unless they were asked shortly after the initial object showing. The study was published in the September/October Child Development (Vol. 80, No. 5).

• The anxiety that comes from a big job interview or rushing to meet an important work deadline may have a silver lining. At least in laboratory mice, bouts of relatively short-term stress boost the immune system and protect against the skin cancer squamous cell carcinoma, according to a study published online in September in Brain, Behavior, and Immunity. Researchers at the Stanford University School of Medicine restricted the movement of UV-exposed laboratory mice for 2.5 hours, nine times over a period of three weeks. They found that fewer of the mice developed skin cancer compared with a control group of non-stressed UV-exposed mice.

• The shift to daylight-saving time brings with it more than just longer days, according to a study in the September Journal of Applied Psychology (Vol. 94, No. 5). Researchers at Michigan State University analyzed the number of injuries reported to the Mine Safety and Health Administration over a period of 24 years and found that on average, there were 3.6 more injuries on the Mondays following the switch to daylight-saving time compared with other days, and 2,649 more days of work lost as a result of those injuries—a 68 percent increase. "People do not generally think that a one-hour time shift could make a difference, but there were surprisingly powerful effects of these small clock changes," says lead author Christopher Barnes, PhD.

• A study in the Journal of Abnormal Psychology (Vol. 118, No. 3) confirms prior research that lesbian, gay and bisexual individuals experience more psychological distress than heterosexual men and women. But the results also suggests that psychiatric risk levels vary among minority sexual orientation populations. Bisexuals, for example, are more likely to experience alcohol dependency than gay men and lesbians. The research was conducted by University of California–Los Angeles epidemiologist Susan D. Cochran, PhD, and psychologist Vickie M. Mays, PhD.

• University of California–Los Angeles psychologists have discovered a genetic link between physical pain and social rejection. In a study, in the Sept. 1 Proceedings of the National Academies of Sciences (Vol. 106, No. 35), researchers used fMRI to capture brain activity while participants played an online ball-tossing game in which they were socially rejected. They found that people with a rare form of the µ-opioid receptor gene, often associated with physical pain sensitivity, were more sensitive to rejection and showed more distress-related brain activity in response to that rejection than those with the more common form of the gene.

• Healthy older brains are not significantly smaller than younger brains, finds a study in September's Neuropsychology (Vol. 23, No. 5), contrary to previous findings. Researchers found that brain volume loss observed in past studies is likely related to pathological changes in the brain that underlie significant cognitive decline rather than to aging itself. "As long as people stay cognitively healthy, the gray matter of areas supporting cognition might not shrink as much as the prevailing opinion holds," says lead author Saartje Burgmans, a doctoral student in the School for Mental Health and Neuroscience at Maastricht University, in the Netherlands.

—A. Novotney