Researchers at Stanford and 14 other institutions carried out a study of common DNA variations throughout the genome, and then combined forces with two independent studies to complete a pooled analysis of 27,000 individuals. The largest genetic differences between the study participants with and without schizophrenia were found on a stretch of chromosome 6 containing numerous genes associated with immune response (and some with other roles). This raises the possibility that immune function plays a role in schizophrenia.

A study in the journal Sleep suggests that postpartum depression may aggravate an already impaired sleep quality, as experiencing difficulties with sleep is a symptom of depression. Twenty-one percent of depressed postpartum women included in the study reported having also been depressed during pregnancy and 46 percent reported at least one previous depressive episode prior to conception, suggesting that new mothers diagnosed with postpartum depression are not merely reporting symptoms of chronic sleep deprivation.

"Previous studies have confirmed a link between smoking in movies and the initiation of smoking by adolescents, and we wanted to dig deeper into the data to see if the type of character who is smoking matters. Is it 'good guys' or 'bad guys' that have more of an influence?" said Susanne Tanski, the lead author on the study, and an assistant professor of pediatrics at Dartmouth Medical School. "It's true that 'bad guys' are more often smokers in the movies, but there really are not that many 'bad guys' compared to 'good guys'. Episode for episode, youth who saw negative character smoking were more likely to start smoking, but since overall there is so much more exposure to 'good guy' smoking, the net effect is similar."

"It is the position of the American Dietetic Association that appropriately planned vegetarian diets, including total vegetarian or vegan diets, are healthful, nutritionally adequate and may provide health benefits in the prevention and treatment of certain diseases. Well-planned vegetarian diets are appropriate for individuals during all stages of the life-cycle including pregnancy, lactation, infancy, childhood and adolescence and for athletes."

Daily sex (or ejaculating daily) for seven days improves men’s sperm quality by reducing the amount of DNA damage, according to an Australian study presented June 30 to the 25th annual meeting of the European Society of Human Reproduction and Embryology in Amsterdam.

It’s common knowledge that a protective navy of bacteria normally floats in our intestinal tracts. Antibiotics at least temporarily disturb the normal balance. But it’s unclear which antibiotics are the most disruptive, and if the full array of “good bacteria” return promptly or remain altered for some time.

New research, to be published July 1 in the journal PLoS One, shows that men under stress may be more likely to take risks, correlating to such real-life behavior as gambling, smoking, unsafe sex and illegal drug use.

Eastman Institute’s YanFang Ren, DDS, PhD, and his team determined that the effects of 6 percent hydrogen peroxide, the common ingredient in professional and over-the-counter whitening products, are insignificant compared to acidic fruit juices. Orange juice markedly decreased hardness and increased roughness of tooth enamel.

Lead author of the study, Associate Professor of Biochemical Medicine at Warwick Medical School Michelle Miller said short-term sleep deprivation studies have shown that inflammatory markers are elevated in sleep-deprived individuals, suggesting that inflammatory mechanisms may play a role in the cardiovascular risk associated with sleep deprivation.