A new study has found that a tuberculosis drug D-Cycloserine, may help people with obsessive-compulsive disorder (OCD) by enhancing progress of therapy sessions by accelerating 'extinction learning'.

The researchers are also working to see whether the drug helps people who want to quit smoking.

The study was conducted by a team of researchers led by Matt Kushner at Researchers at the University of Minnesota.

Researchers explained that behavioural therapy attempted to help the person disassociate problematic reactions that were 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 and the drug might increase people's ability to put out the various cues.

As part of the research, investigators separated the people with OCD into two groups. One group received the drug and another that received a placebo several hours before psychotherapy.

Researchers found progress in therapy was quicker in those who took the drug and they were less likely to quit therapy when 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 investigators are now studying how the drug's effect on smokers' who want to quit.

"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.