The following dissertation presents original research on selected topics in the epidemiology of cocaine use and dependence. The research consists of inter-related studies that deal with gaps in scientific knowledge about the topics pertinent to drug dependence. The dissertation is focused on four studies:In study one, I seek to estimate a suspected causal association between cocaine use and the occurrence of panic during adolescence and young adulthood, building upon prior study results based upon adult samples. The data are from an epidemiological sample of young adults, observed longitudinally from primary school to that time. The main finding is a modest but generally statistically robust association linking cocaine use and the occurrence of a panic attack-like experience.In study two, I attempt to estimate a suspected causal association linking earlier onset of cocaine use with later risk of newly incident panic attack in adults. The data are from an epidemiological sample of Americans aged 18-44 years at the time of cross-sectional and retrospective assessment. The main findings of this study confirm prior evidence on the suspected causal association linking cocaine use with subsequent panic attack-like events. In this study, temporal sequencing of the association has been assured to the extent possible in retrospective age of onset data, with a conservative approach when the first cocaine and panic occurred in the same year.In study three, the aim is to estimate the risk of becoming cocaine dependent in the first months and years after onset of cocaine use, and to study suspected determinants of becoming dependent within 24 months after cocaine use starts, based on nationally representative samples of non-institutionalized citizens of the United States aged 12 years and older. The main findings of this study are as follows. First, an estimated 6-7% of recent-onset users develop cocaine dependence. Excess risk of cocaine dependence was found for females. Occurrence of cocaine dependence was greater among newly incident users who had started to smoke crack cocaine, as compared to those who had not smoked crack. No remarkable associations were found with the other variables under study (e.g., age, race-ethnicity).In study four, I seek to provide epidemiological evidence on predictors of who has started cocaine use in the last four years but has stopped using cocaine. The data for this research also are from nationally representative samples. The approach starts with exploratory analyses of data from calendar year 2003 (CY2003). Then, the model is re-evaluated using data from an independent sample drawn in CY2008. The main findings are as follows. First, among those whose onset of cocaine use was within the four years prior to the date of the survey assessment, an estimated 13-16% had remained cocaine users within the prior 30 days; and an estimated 34% used cocaine within past 12 months but not in the past 30 days. An estimated 50-53% had not used cocaine in the previous 12 months before the assessment. It was found that people with age of cocaine onset at 20 years old or greater are twofold more likely to stop; this is the only finding from the CY2003 analysis that could be replicated in the CY2008 analysis. Cocaine cessation was not found to be reliably associated with sex, education, or using crack-cocaine.
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