Cocaine Use and the Occurrence of Panic Attacks in the Community: A Case-Crossover Approach

Abstract

The epidemiologic case-crossover method is a powerful tool for research on suspected hazards of illegal drug use, the advantage being a subject-as-own-control approach that constrains stable individual-level susceptibility traits. Here, we use the case-crossover method to estimate the magnitude of excess occurrence of panic attacks during months of cocaine use vs. months of no cocaine use, motivated by a prior estimate that cocaine users have three-fold excess risk of panic attack. The self-report data on cocaine and panic are from assessments of a nationally representative sample of 1071 recent panic cases age 18 years or older identified as part of the National Household Surveys on Drug Abuse conducted in the United States during 1994–1997. Based on case-crossover estimates, cocaine use is associated with a three- to- four-fold excess occurrence of panic attack (estimated relative risk (RR) = 3.3, p = 0.049; 95% confidence interval: 1.0, 13.7). Year-by-year, the RR estimates from four independent yearly replicates (1994–1997) are 5.0, 2.0, 3.0, and 3.0. While there are several important limitations, this study adds new evidence about a previously reported suspected causal association linking cocaine use to occurrence of panic attacks, and illustrates advantages of the epidemiologic case-crossover approach and new directions in research on hazards of illegal drug use.

Keywords:

• comorbidity
• panic disorder
• cocaine
• case-crossover design
• drug use
• epidemiology
• illegal drugs

Additional information

Notes on contributors

Megan S. O'Brien

Megan S. O'Brien, Ph.D., is a NIDA Postdoctoral Fellow in the Department of Mental Health at the Johns Hopkins Bloomberg School of Public Health. She is a community psychologist with interests in social capital and drug use among nonurban populations.

Li-Tzy Wu

Li-Tzy Wu, Sc.D., is a psychiatric epidemiologist at RTI International with interests in psychiatric comorbidity and mental health service utilization.

James C. Anthony

James C. (Jim) Anthony, Ph.D., now is professor and chairman of the department of epidemiology in the medical school at the Michigan State University. The topic of this Substance Use and Misuse paper relates to one of the central themes in his research program–estimation of the degree to which drug use might increase risk of psychiatric and behavioral disturbances, and whether there is any increased risk at all.