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School of Medicine
Psychiatry Newsletter - Our variety's showing
Hopkins BrainWise - Winter 2012
Our variety's showing
Date: January 2, 2012
Straight story on cutting
Sometimes people do things to hurt themselves on purpose, like cutting, scratching, burning or injuring themselves in other ways. Have you ever done something like that? It’s not a typical college questionnaire question, but psychiatric epidemiologist Holly Wilcox wanted better information on non-suicidal self-injury (NSSI) that mostly targets adolescents. Small studies have offered likely risk factors and motives, but a larger study that follows people over time could help predict and prevent the troubling behavior.
Wilcox’s team interviewed more than 1,200 college freshmen, checking on them annually through college and assessing, for example, NSSI frequency, the students’ ability to regulate emotion and their breadth of social support.
Among the findings: NSSI in this age group often repeats itself. And having depression, a depressed mother, homosexual orientation and poor ways of controlling emotion especially point to future bouts of self-made injury.
For information: 410-502-0629.
Olanzapine? Can’t say no to dough
When olanzapine (OLZ) appeared in the 1990s, clinicians were heartened at having something new for psychosis. That turned to dismay as the useful agent’s possible metabolic side effects—obesity and diabetes—became clear. To help explain OLZ’s dark side, Kellie Tamashiro and colleagues studied rat models’ response to the drug, both short and longer-term. Control animals were offered plain sugar cookie dough for either five days or three weeks. Test counterparts got dough dosed with OLZ.
By study’s end, rats on olanzapine were roughly 10 percent heavier, thanks, the team found, to a fairly dramatic appetite increase early on. They stayed fatter throughout—the gain was due to fat—though appetites later dropped. And they’d become less insulin-responsive. A profile of regulatory neuropeptides in the animals’ brains revealed a pattern that’s typical of calorie-starved people who are moved to eat.
For information: 410-614-9151.
Stress’s environmental toehold?
Serotonin-based pathways in the nervous system rule, in part, over the body’s response to stress. So it’s no surprise that the serotonin transporter—the molecule that ferries “spent” serotonin out of synapses—has been under scrutiny. The thought is that flawed serotonin transport somehow upsets a person’s ability to adapt to stress.
Study of the transporter extends to its gene. Apparently, a number of downsides come with having a shorter version of that gene’s regulatory part, including subtle brain abnormalities and a tendency to depression.
To verify the stress/gene interaction, a team including Dimitrios Avramopoulos studied 1,875 new recruits into military service, a banner time for stress. Recruits carrying pairs of genes for the transporter’s short form, the team found, were indeed more likely to show paranoid or defensive reactions under boot camp’s rigors.
For information: 410-955-8725.
Master molecule rules fat and more
Neuropeptide Y, well known for increasing appetite, is surprisingly more of a jack-of-all-trades, according to a recent lab rat study. The work, led by Sheng Bi, in which expression of the protein in the brain’s hypothalamus was damped down, suggests NPY is critical in regulating body weight: It affects how much is eaten, what kind of fat results, levels of body heat and energy expenditure. That’s not to mention urges for physical activity.
Most interesting is that lowering hypothalamic NPY in the animals turned off the overeating that high-fat diets prompt and the obesity that follows. It enhanced sensitivity to insulin. To the researchers’ near-amazement, it also shifted the animals’ white fat into energy-burning brown fat. It’s a treasure chest of targets, they say, for obesity and diabetes.
For information: 410-502-4789.
More enzyme, less nice to be near
Antisocial personality (ASP) traits like irresponsibility, lack of remorse or deceitfulness are all too common. And because people with more than one trait typically push hard on society’s boundaries, there’s interest in finding what mix of genes and environment brings traits out. Studies in the 1960s raised the intriguing idea that those with ASP are short on monoamine oxidase (MAO)—the enzyme that clears serotonin, norepinephrine and dopamine from synapses. Mice with low MAO, for example, are Feisty with a capital F.
Newer work found that people vary in the regulatory part of the MAO gene that oversees how much enzyme is created. It’s reasonable to think, then, that those with a low-producing gene are more prone to have the antisocial traits.
The trouble is that human studies aiming to show that have muddy results. Irving Reti suspects the reason isn’t so much biology as it is environment: The effect of a bad childhood likely swamps the data.
So Reti’s team divided a large number of participants in a Baltimore community survey—narrowed to people with ASP traits—into those with childhood abuse and those without. That made the association between antisocial behavior and available MAO stand out clearly.
For information: 410-614-1732.
More drama from the trauma
A mugging. A terrible burn. The ability of severe trauma to set off acute stress disorder within days, or PTSD some weeks later, is well known. But how to predict who’ll go on to suffer them after a traumatic event and who won’t? Finding a biologic marker for people whose hypervigilance and other characteristic symptoms will be longer-lasting is a firm step on the road to tailored therapy. Looking solely at burn patients, Neda Gould, James Fauerbach and their team focused on heart rate and blood pressure. The latter wasn’t a predictor. But high heart rate in the ambulance after a burn occurs, they found, foreshadows a higher risk of acute stress disorder or PTSD some six months after a patient leaves the hospital.
For information: 410-550-0890.
When mother hovers
We all know mothers who insert themselves into a child’s life, and though their intentions are good, that doesn’t seem right. Solid study agrees: Maternal overcontrol is clearly linked with higher anxiety in children. But how? Golda Ginsburg says it has to do with undermining a child’s sense of competence. Now her new work supports that. In a study of 89 mother/preteen pairs, the outcomes show that having mothers who need to know a child’s every move, for example, results in offspring who feel less than capable as well as more anxious. The idea, Ginsburg says, is that parental overcontrol teaches children they’re not able to handle many situations and that, in turn, leads to high anxiety.
For information: 410-955-1544.