Trauma Memories Increase Drug Abusers' Craving

BUFFALO, N.Y. -- Post-traumatic stress disorder (PTSD) increases craving in drug abusers diagnosed with both conditions, confirming the need to treat the conditions simultaneously, the first laboratory study of the two disorders has shown.

Research drawing that conclusion, led by Scott F. Coffey, Ph.D., assistant professor of psychiatry in the University at Buffalo School of Medicine and Biomedical Sciences, appears in the current issue of Drug and Alcohol Dependence.

"We know from experience that drug abusers with PTSD do poorly in treatment," Coffey said, "but many providers of substance-abuse treatment are reluctant to treat PTSD because it's such an emotionally charged condition. Common practice is to treat the drug abuse and then the PTSD.

"But if the PTSD symptoms are in part driving the substance abuse, asking a patient to get off drugs before treating the PTSD is kind of unfair," he said. "We don't do that with drug abusers with depression or schizophrenia; we treat the two disorders concurrently. Hopefully, this study will encourage treatment providers to address drug abuse and PTSD at the same time."

It's estimated that as many as 40 percent of substance abusers suffer from PTSD, he said.

Coffey, a specialist in drug abuse and PTSD, conducted the research with colleagues at the Medical University of South Carolina. The investigators used a laboratory-based approach called "cue reactivity," in which subjects are exposed to stimuli designed to remind them of a particular event or situation in order to monitor their responses.

The study involved 30 cocaine-dependent and 45 alcohol-dependent participants, all of whom also suffered from PTSD resulting from a physical or sexual attack. All participants were in treatment for their substance dependence, and were drug-free at the time of the study, but reported using their drug of choice within the past 60 days.

During the initial interview, researchers asked participants to describe their worst trauma in full detail, including physical sensations, thoughts and emotions. With the participants' permission, this information was used to create a 50-second audiotaped narrative that would serve as the trauma-imagery cue during the laboratory session.

Each participant also rated five standard neutral audio narratives for pleasantness and emotional arousal. The script that participants rated closest to neutral was used as their neutral imagery cue.

In addition, interviewers discussed participants' drug of choice, and used the information to develop individualized drug cues: for the cocaine abusers, a crack pipe and bag of simulated crack cocaine that participants thought was real; for the alcohol abusers, a glass of the preferred alcoholic beverage, presented in the preferred manner, e.g., vodka over ice, along with the bottle itself. Wood chips served as the neutral "drug" cue for all participants.

Each laboratory session began with a urine drug screen and questionnaire on which participants reported their current level of craving. Retiring to a sound-proof booth, subjects underwent four presentations of imagery and drug cues: trauma imagery followed by a drug cue, neutral imagery followed by a drug cue, trauma imagery followed by a neutral cue and neutral imagery followed by a neutral cue.

Participants listened to the imagery recordings through earphones with eyes closed and were asked to continue to imagine the scene and experience the emotions as vividly as possible. When a buzzer signaled them to open their eyes, they were confronted by a drug or neutral cue.

Participants rated their craving and other responses on a computerized questionnaire immediately following each imagery-drug presentation.

Results showed, not unexpectedly, that craving increased significantly when participants were presented with trauma imagery and when participants were presented with cues related to their substance of choice.

"From our research with trauma victims, we know that intrusive trauma memories are very upsetting to patients, and now we have shown that these trauma memory-induced negative emotions increase craving in substance abusers with PTSD," Coffey said. "These findings add support to our contention that we need to treat the two disorders at the same time."

This first investigation involving parallel experiments with cocaine and alcohol abusers also turned up unexpected findings, he said. "We predicted that cocaine abusers would have significantly higher craving than alcohol abusers, based on our knowledge of cocaine's effects. But we found that people with alcohol dependence reported much higher craving than cocaine abusers when thinking about their trauma."

Coffey said this finding makes sense in hindsight: "PTSD is an anxiety disorder. It makes people become aroused, so they are much more likely to need an anxiety-reducing drug, like alcohol, than a stimulant, like cocaine, which would increase the arousal."

In his practice, Coffey is using one of a new group of experimental psychotherapeutic treatments reported in the literature that may be effective in treating both disorders simultaneously, and has received funding from the National Institute on Alcohol Abuse and Alcoholism to continue this line of research.

His work reported in Drug and Alcohol Dependence was supported by a grant from the National Institute on Drug Abuse.