Journal Digest

Teens With TBI Report More Substance Use

Teens who experienced at least one traumatic brain injury (TBI) reported drug use that was two to four times higher than their peers, reports a new study in the Journal of Head Trauma Rehabilitation.

Researchers from St. Michael’s Hospital and CAMH in Toronto and from Dalhousie University in Halifax examined survey data from about 6,400 high school students in Ontario and found that the students who reported a TBI also were more likely to engage in substance use, whether it was smoking tobacco, drinking, using marijuana, or taking prescription or illegal drugs.

Among the various drug categories, crystal meth and sedatives posed the highest risk, as teens with a history of TBI were 3.8 times as likely to use these substances compared with peers.

The authors pointed out that the study methodology did not allow them to determine whether the drug use or TBI occurred first in the students, though they hope to elucidate the directionality with further studies.

They noted, however, that the association is problematic in any instance, since drug and alcohol use can both increase the risk of head injury and impair the recovery process afterwards.

Brain Activity Might Predict Risk of Smoking Relapse

Smokers who relapsed within seven days of their target quit date had specific patterns of activity in the brain section that controls working memory, reported authors of a new study from the University of Pennsylvania.

These findings suggest that neuroimaging assessments could be used to identify smokers with a greater risk of early relapse when trying to quit smoking, which therapists could use to tailor cessation regimens.

As reported in Neuropsychopharmacology, functional magnetic resonance imaging (fMRI) of 80 smokers attempting to quit smoking identified decreased activity in the dorsolateral prefrontal cortex in smokers who relapsed a week after their quit date, compared with those who successfully abstained for that same time.

Each participant had two images taken, one immediately after a smoke, and a second one 24 hours after cessation. In addition to changes in the prefrontal cortex, the images showed some increases in activity in the posterior cingulate cortex, which is involved in introspection, among those who relapsed.

The researchers also incorporated the functional imaging into a model for predicting early relapse and found it had an 81 percent success rate, which, they noted, is higher than current methods using clinical and behavioral indicators.

Job Authority Increases Depression Symptoms In Women

Job authority has gender-specific influences on depressive symptoms, found a study reported in the Journal of Health and Social Behavior.

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Men with authority at work tended to show fewer depressive symptoms, whereas women with authority showed more such symptoms.

The researchers used data from the Wisconsin Longitudinal Study to examine the effects of job authority for nearly 3,000 middle-aged men and women from 1993 to 2004. While women showed increased prevalence of depression overall, the discrepancies in depressive symptoms were much greater among women with job authority—classified as having control over other people’s work.

This increased prevalence stands out as the women with job authority displayed several other traits that are associated with positive mental health, such as higher education, income, and job satisfaction.

“Women in authority positions are viewed as lacking the assertiveness and confidence of strong leaders,” said lead study author Tetyana Pudrovska, Ph.D., of the University of Texas. “But when these women display such characteristics, they are judged negatively for being unfeminine. This contributes to chronic stress.”

Pudrovska said that these findings indicate a need to address gender discrimination in the workplace to reduce the psychological costs facing women with high-status jobs.

Treating Sleep Apnea May Alleviate Depression

Treating obstructive sleep apnea (OSA) can lead to modest improvements in depressive symptoms, a new review study in PLoS Medicine has found.

This analysis compiled data from 22 sleep apnea clinical studies involving either continuous positive airway pressure (CPAP) or mandibular advancement devices. Both treatments improved depressive symptoms in OSA patients, compared with those receiving control interventions, with greater improvements shown for people who had higher levels of depression prior to the apnea treatment, which suggests that improved sleep may not be the sole determinant in improving mood.

The authors, from the University of Calgary, cautioned that the results for the individual CPAP studies did vary widely, so the accuracy may be somewhat limited.

In addition, none of the studies examined the efficacy of sleep apnea treatment in this population in comparison with treatment using antidepressants, so these results cannot inform any treatment recommendations. The authors suggested that such a comparison study would be worthwhile for future work to understand the link between sleep apnea and depression.

Cancer Drug Shows Benefits in Mouse Model of Fragile X Syndrome

Cercosporamide, a drug being tested in lung cancer and leukemia therapy, improves the social behavior of mice with a version of fragile X syndrome (FXS)—the most common genetic cause of autism.

Cercosporamide reduces the levels of an enzyme known as matrix metalloproteinase 9 (MMP-9). Researchers at the University of Edinburgh and McGill University and colleagues had found that brain samples from both humans with FXS and mouse models of this disorder showed increased levels of MMP-9, suggesting a crucial role.

To test whether the elevated MMP-9 played an active role in the disease, the researchers overexpressed this protein in mice and found that it did lead to FXS-like social deficits such as fewer interactions with novel mice and increased grooming.

Said study researcher Christos Gkogkas, Ph.D., “Our findings open the door to targeted treatments for fragile X syndrome. By designing treatments that block just this pathway, it is hoped we can limit the potential side effects and develop therapies that are more efficient than general approaches.”

This study was published online in Cell Reports. ■