Abusive treatment of children, including bullying, increased the likelihood of psychotic symptoms at age 12 in a nationally representative sample of twins assessed between ages 5 and 12. Arseneault et al. (CME, p. 65) report that the effect of maltreatment was not related to genetic risk, socioeconomic status, and age at the time of maltreatment. Accidents were also associated with greater risk of psychotic symptoms at age 12 but to a lesser degree than traumas with the intention to harm. The combination of maltreatment by an adult and bullying by peers increased the risk of psychotic symptoms more than either one alone. The growing evidence of adverse long-term outcomes from childhood abuse is described by Cohen in an editorial (p. 7).

The likelihood of posttraumatic stress disorder (PTSD) in Dutch military personnel sent to Afghanistan was greater in those with higher predeployment numbers of glucocorticoid receptors, conveyors of hormones affecting immunity, metabolism, and inflammation. The relationship discovered by van Zuiden et al. (p. 89) was independent of posttraumatic depressive symptoms and traumatic childhood experiences. With each increase of 1,000 glucocorticoid receptors in peripheral mononuclear cells, the odds of PTSD increased 7.5-fold. The increase persisted 1 and 6 months after deployment. Delahanty, in an editorial (p. 9), points out that there was considerable overlap in levels of glucocorticoid receptors between those who did and did not develop PTSD, but nonetheless this measure represents an interesting addition to the other risk factors that might help predict who develops PTSD.

The relationship between suicide risk and elevation was confirmed by a nationwide study that also examined the possibility of intermediate roles of gun ownership and low population density. Kim et al. (p. 49) analyzed county- and state-level databases and found that rates of both firearm and non-firearm suicides were correlated with county altitude. Gun ownership and low population density were also associated with the suicide rate, but the role of altitude was separate from these other factors. To minimize the influence of cultural factors, the researchers conducted a parallel study in South Korea, which has variable geography and a relatively high suicide rate. Altitude and the number of suicides over a 4-year period again showed a strong correlation. This association does not indicate a causal relationship between elevation and suicide, but mild hypoxia may increase metabolic stress in people with mood disorders.