Once considered a childhood rite of passage, bullying lingers well into adulthood. Bullies and victims alike are at risk for psychiatric problems such as anxiety, depression, substance abuse, and suicide when they become adults, reported a study partially funded by the National Institute of Mental Health (NIMH) that was published in the April issue of JAMA Psychiatry.
Scientists, for the first time, have switched anxiety on-and-off in active animals by shining light at a brain pathway. Instinctively reclusive mice suddenly began exploring normally forbidding open spaces when a blue laser activated the pathway – and retreated into a protected area when it dimmed. By contrast, anxiety-like behaviors increased when an amber laser inhibited the same pathway.
Adult mice engineered to have more newborn neurons in their brain memory hub excelled at accurately discriminating between similar experiences – an ability that declines with normal aging and in some anxiety disorders. Boosting such neurogenesis in the adult hippocampus also produced antidepressant-like effects when combined with exercise, in the study funded by the National Institutes of Health.
A study has linked panic disorder to a wayward hormone in a brain circuit that regulates vigilance. While too little of the hormone, called orexin, is known to underlie narcolepsy, the new study suggests that too much of it may lead to panic attacks that afflict 6 million American adults.