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Results of combined-treatment studies can be varied and confusing, as a result of methodology, researcher bias and patient characteristics, experts say. In fact, even the order in which you give treatments may make a difference, as may patients' treatment preference, notes Stony Brook University psychologist and depression researcher Daniel Klein, PhD.

Fortunately, research on combined treatments is becoming more sophisticated in design, theory and potential application, says David H. Barlow, PhD, director of Boston University's Center for Anxiety and Related Disorders. This evolution bodes well both for research and treatment, he believes.

The original studies on combined treatments tested drugs and therapy at the same time. The problem with this approach was a lack of theoretical rationale and hence a conflicting record of results. "No one provided a really good reason as to why these treatments might do better than one treatment alone," Barlow says.

A more sensible strategy that's being increasingly used examines "sequential" treatments, where researchers start with one treatment and either add or substitute a second one if the first isn't producing adequate results. This methodology promises to help tailor treatments and save money, Barlow says.

Now, researchers are launching what Barlow thinks may be the most effective research design yet: combining therapy with drugs developed specifically to work with a given psychological treatment-so-called "synergistic" treatments. For example, scientists are adding D-cycloserine-an old tuberculosis antibiotic recently shown to help extinguish fear in animals-as a complement to psychological treatments for conditions such as obsessive-compulsive disorder and post-traumatic stress disorder (PTSD). (See the January Monitor for its application to PTSD.)

Likewise, they're looking into possible applications of the hormone oxytocin to treat people with social anxiety, Barlow says. Traditionally used to stimulate labor and breastfeeding in women, oxytocin also helps to promote trust and bonding, which could help people with social anxiety overcome their fears, he notes.

--T. DeAngelis