NDARC Technical Report No. 116 (2001)
A recent study of cocaine use in Sydney found that there were significant proportions of both injecting and non-injecting cocaine users that exceeded the proposed diagnostic cut-off score for cocaine dependence on the Severity of Dependence Scale (SDS), and that level of dependence was the most influential mediator in the relationship between the use and associated harms of cocaine. Irrespective of the route of administration, dependence was associated with poorer physical and psychological health.
The current study aimed to further investigate the cocaine dependence syndrome by examining the prevalence, correlates, symptoms, and diagnosis of dependence among both injectors and non-injectors of cocaine. This study also endeavoured to ascertain the SDS cut-off score that best discriminates between the presence or absence of a DSM-IV diagnosis of cocaine dependence. The final aim of the current study was to extend upon previous research and determine the prevalence and nature of cocaine-induced physical and psychological health problems.
A sample of 96 injecting cocaine users and 46 non-injecting cocaine users were interviewed about their frequency and methods of cocaine use, as well as about any physical and/or psychological problems that they attributed to such use. Subjects were administered two different measures of dependence; the Composite International Diagnostic Interview (CIDI) and the SDS.
Cocaine dependence was highly prevalent among ICU, with almost half (47%) of cocaine injectors qualifying for a DSM-IV diagnosis of dependence. Among NICU, cocaine dependence was of a lower, but still significant, prevalence, with over one-fifth (22%) of subjects qualifying for a diagnosis of dependence.
Cocaine-dependent ICU were more likely to have experienced cocaine-induced physical (76% vs 43%) and psychological (80% vs 39%) problems in the previous 12 months than non-dependent ICU. Similarly, greater proportions of cocaine-dependent NICU reported physical (90% vs 44%) and psychological (100% vs 42%) problems than non-dependent NICU. Route of administration was not found to be a significant predictor of cocaine dependence. Frequency of use over the preceding six months was the only factor that was independently associated with dependence.
There was a high prevalence of cocaine-related problems among ICU and NICU, with more than half of each group reporting that they had experienced physical (ICU-58%; NICU-54%) and/or psychological (ICU-58%; NICU-54%) problems in the preceding 12 months. Among ICU, the most common physical problems were palpitations, headaches, and sleep problems. Among NICU, the most common physical problems were numbness/tingling, nasal problems, and sleep problems. The most common psychological problems among both ICU and NICU were paranoia, mood swings, and agitation. Route of administration did not appear to play a role in the likelihood of having experienced such problems.
The SDS was found to be an accurate diagnostic tool to measure the presence or absence of cocaine dependence. A score of 3 on the SDS was revealed by ROC analysis to be the cut-off point which best discriminates between the presence or absence of a DSM-IV diagnosis of cocaine dependence.
In summary, this study revealed that cocaine is a drug with the potential to cause dependence, as well as a number of physical and psychological problems, among a broad spectrum of users with various patterns and methods of use. Cocaine dependence among injecting and non-injecting users was of a level sufficient to cause concern and warrant further research. While subjects who had used cocaine more frequently were more likely to be cocaine-dependent, a diagnosis of dependence was not contingent on a high frequency of use. Thus, the potential for irregular, as well as regular, users of cocaine to develop cocaine dependence should be recognized and factored into the development of harm minimization or treatment strategies. It is concluded that the use of cocaine should be treated as an issue of serious concern and remain a focus of future research.