Researchers examine substance use patterns among people who use cocaine

A new University of Florida study finds a number of complex patterns of polysubstance abuse among people who use cocaine. The findings appear in the journal Addictive Behavior Reports.

“Past research on cocaine polysubstance use mostly dichotomized all cocaine users into those who only used cocaine and those who used cocaine plus one other substance,” said lead author Ms. Yiyang Liu, a doctoral student in epidemiology at the University of Florida College of Public Health and Health Professions and College of Medicine. “However, patterns of polysubstance with more than two substances are typically ignored. In our study, we used latent class analysis to examine the complex patterns of polysubstance use among lifetime cocaine users.”

For the study, UF researchers asked participants about their past 30-day and other lifetime use of cocaine, alcohol, tobacco, marijuana and prescription medications. They also asked participants about mental health conditions and recent emergency department visits.

Using a modeling technique called latent class analysis, the researchers identified five patterns of past 30-day substance use among nearly 2,000 lifetime cocaine users. These included tobacco use only; alcohol, marijuana and tobacco use; tobacco, prescription opioid and sedative use; cocaine, alcohol, marijuana and tobacco use; and cocaine and multiple polysubstance use.

“Our findings indicate that cocaine polysubstance users are a heterogeneous group,” Ms. Liu said. “We found that there are several different patterns of use and each has different risk factors. This suggests one unified intervention may not work well for all cocaine users.”

Ms. Liu said that personalized interventions may be most effective for reducing risk associated with these substance use patterns.

With funding from the National Institute on Drug Abuse, Dr. Linda B. Cottler, a UF professor of epidemiology and PHHP’s associate dean for research, and Dr. Lori Knackstedt, an associate professor in the UF department of psychology, are conducting a study that will shed more light on patterns of substance use among cocaine users. They are studying details about simultaneous versus concomitant use of drugs, taking into account the time of day, day of the week and order of use. These patterns will then be used in rat models to understand their effect on brain function.

In addition to Ms. Liu, the research team included her mentor, Dr. Cottler; Ms. Amy Elliott and Ms. Mirsada Serdarevic, UF doctoral students in epidemiology; and Dr. Robert Leeman, an associate professor of health education and behavior in UF’s College of Health and Human Performance.