Stories about: post-traumatic stress disorder

Could targeting specific neurons in the hypothalamus relieve anxiety?

anxiety hypothalamus
(Ichiban Yada/Sketchport.com)

Anxiety disorders are the most common mental illness in the U.S., but lack an ideal treatment. The current drugs, SSRIs and benzodiazepines, have many side effects. More recently developed treatments seek to block corticotropin-releasing hormone (CRH), the classic stress hormone that activates our “fight or flight” response; in people with anxiety, CRH gets activated at the wrong time or too intensely.

But in clinical trials, results have been disappointing: of the eight completed phase II and III trials of CRH antagonists for depression or anxiety, six have been published, with largely negative findings, says Joseph Majzoub, MD, of the Division of Endocrinology at Boston Children’s Hospital.

Rong Zhang, PhD, who works in Majzoub’s research lab, had a hunch that blocking CRH throughout the brain, as was done in these trials, isn’t the best approach. “Blocking CRH receptors all over the brain doesn’t work,” she says. “We think the effects work against each other somehow. It may be that CRH has different effects depending on where in the brain it is produced.”

Today in Molecular Psychiatry, Zhang, Majzoub and colleagues demonstrate that certain neurons in the hypothalamus play a central, previously unknown role in triggering anxiety. When they used genetic tricks to selectively remove the CRH gene from about 1,000 of these neurons in mice, the effect was startling — they erased the animals’ natural fears.

Read Full Story | Leave a Comment

Who is most at risk for PTSD after trauma? Lessons from the Boston Marathon bombings

PTSD risk in adolescents after Boston Marathon bombingsDaniel Busso, MSc, is a doctoral student at the Harvard Graduate School of Education and a researcher in the Sheridan Laboratory at Boston Children’s Hospital.

More than 60 percent of teenagers have experienced a traumatic event in their lifetime, but only a minority will develop post-traumatic stress disorder (PTSD). For both researchers and clinicians, this raises an important question: Why are some youth at greater risk for mental health problems after trauma? As our lab reports in two recent studies, conducted after the 2013 Boston Marathon bombings, the answer may lie in our neurobiology.

PTSD, which includes intrusive memories, increased anxiety and difficulty concentrating or sleeping, has been linked to a variety of psychosocial and biological risk factors, such as prior experiences of trauma or a history of mental health problems. Other studies suggest that disruptions to the body’s stress response system, or in patterns of brain activity when responding to threat, may predispose people to the disorder.

However, a common problem in this research is that biological and mental health data are collected only once, usually long after the traumatic event itself,

Read Full Story | Leave a Comment