Researchers at the University of Minnesota have found that a drug originally developed to fight tuberculosis may help people with obsessive-compulsive disorder make more progress in therapy sessions. Now they want to see if this drug could have a similar effect on people who want to quit smoking.
The research, led by Matt Kushner, Ph.D., was published in the online edition of Biological Psychiatry, and will appear in an upcoming print edition. Kushner’s collaborators include Suck Won Kim, M.D., and Christopher Donahue, Ph.D.
The drug, D-Cycloserine, is believed to help accelerate “extinction learning.” On a basic level, people associate positive or negative feelings with various cues from the external world. Behavioral therapy attempts to help the person disassociate problematic reactions that are either positive (e.g., craving to use an addictive substance) or negative (e.g., fear of some catastrophic outcome) from the cues that trigger these feelings.
“This offers another therapeutic approach where we can attempt to manipulate the memory process and the brain’s reward/punishment system so people can learn healthier responses to various cues,” Kushner said.
For example, a person with OCD may have negative feelings before or after touching a doorknob. In psychotherapy, the person would work on disassociating the negative feeling with the external cue of seeing or touching a doorknob.
In this research project, investigators separated the people with OCD into two groups. One group received the drug and another received a placebo several hours before psychotherapy.
Kushner found that those who took the drug made progress in therapy more quickly and were less likely to quit therapy compared with the placebo group. The research subjects who took the drug reported feeling less distress or anxiety due to their obsessions or compulsions. The drug seemed to be most effective in the first few therapy sessions.
Over time, people in the placebo group could catch up in terms of therapy goals, but more study participants in the placebo group dropped out of therapy. “The dropout rate decreased dramatically,” Kushner said. “Typically about 20 to 30 percent of people with OCD drop out of therapy. Only 7 percent of people who took the D-Cycloserine dropped out.”
Kushner said that the drug will not work by itself; it must be done in conjunction with therapy to be effective.
Kushner and his team are now studying how the drug will effect smokers’ who want to quit, and they are seeking smokers to participate in a research study. “People who smoke have positive feelings from the drug effects of nicotine associated with exposure to cues of smoking, such as seeing a pack of cigarettes, lighting up, or actually smoking,” Kushner said. “This research project investigates whether or not we will see a similar extinction learning effect in people who smoke.”
Study participants will be given nicotine-extracted cigarettes to smoke, and similar to the previous study, one group will receive the drug, another the placebo, prior to therapy sessions. Participants will attend sessions once per week for four weeks, and they will be asked to smoke only the nicotine-extracted cigarettes in between the sessions.