Sedatives may slow recovery from trauma

GIVING sleeping pills to soldiers and earthquake victims is common practice, yet it could be doing more harm than good. That's the suggestion from a study of traumatised rats, which seemed to show that the drugs suppressed the rodent's natural mechanisms for coping with trauma.

The US Department of Veterans Affairs says it will consider this and other studies when preparing new guidelines on treatments for post-traumatic stress disorder (PTSD). If their results are strong enough, it may recommend withholding sedatives in the aftermath of traumatic events. The findings are also throwing up new possibilities for preventing PTSD (see "Fight stress with stress").

PTSD arises after a person has had a traumatic experience: symptoms include involuntary, often debilitating, flashbacks of the experience, which can keep happening for years. Not everyone develops it, though, and it seems that what happens directly after the event, as the brain lays down the memory, helps determine whether they do.

Benzodiazepines, a class of sedative that includes diazepam (Valium), are prescribed following a traumatic event because they reduce anxiety and aid sleep. However, some studies have suggested that they may hamper long-term recovery.

For example, a 2002 study of 22 volunteers who had experienced traumas such as traffic accidents found that those given a benzodiazepine for the following seven nights showed slightly more symptoms of PTSD six weeks later compared with those given a placebo.

To investigate further, Joseph Zohar and colleagues at Ben-Gurion University of the Negev in Beer Sheva, Israel, put rats in a confined space with well-soiled cat litter - a highly stressful experience used to gain insights into PTSD. Some were given the benzodiazepine alprazolam, while others were left untreated.

Despite a short-term reduction in anxiety, 30 days later the treated rats displayed more PTSD-like symptoms, such as freezing in response to unused cat litter, increased anxiety and less time exploring a maze, something they usually enjoy. As well as this, treated rats had lower blood levels of corticosterone, the rat equivalent of the human stress hormone cortisol, compared with untreated rats