Assessing illicit drug use among adults with schizophrenia

Abstract

Accurate drug use assessment is vital to understanding the prevalence, course, treatment needs, and outcomes among individuals with schizophrenia because they are thought to remain at long-term risk for negative drug use outcomes, even in the absence of drug use disorder. This study evaluated self-report and biological measures for assessing illicit drug use in the Clinical Antipsychotic Trials of Intervention Effectiveness study (N=1460). Performance was good across assessment methods, but differed as a function of drug type, measure, and race. With the Structured Clinical Interview for DSM-III-R as the criterion, self-report evidenced greater concordance, accuracy and agreement overall, and for marijuana, cocaine, and stimulants specifically, than did urinalysis and hair assays, whereas biological measures outperformed self-report for detection of opiates. Performance of the biological measures was better when self-report was the criterion, but poorer for black compared white participants. Overall, findings suggest that self-report is able to garner accurate information regarding illicit drug use among adults with schizophrenia. Further work is needed to understand the differential performance of assessment approaches by drug type, overall and as a function of race, in this population.

Screening for substance use disorders in first-episode psychosis: Implications for readmission

“…In agreement with other recent European studies in first-episode psychosis samples (Cantwell et al, 1999; Barnes et al, 2006; Larsen et al, 2006; Kamali et al, 2009; Van Dorn et al, 2012), cannabis was the most frequently reported substance of abuse, followed by alcohol and cocaine. The DALI cannabis/cocaine subscale showed that 50% of individuals with first-episode psychosis were at risk of a cannabis and/or cocaine use disorder and 19.0% at risk of alcohol use disorders, a rate that is in the upper range for these studies (Cantwell et al, 1999; Barnes et al, 2006; Larsen et al, 2006; Kamali et al, 2009; Van Dorn et al, 2012). This may be explained by local and national differences in the pattern of substance misuse, as Spain is among the countries with the highest prevalence of alcohol, cannabis and cocaine use (European Monitoring Centre for Drugs and Drug Addiction, 2011).…”

Latent class analysis of discordance between results of drug use assessments in the CATIE data

“…Indeed, requiring at least two positive results would categorize those in RIA discordant as non-users . The prevalence of substance users in our study, conservatively limited to those in the users and probable users classes, is 23.8%; this value falls on the low end of prevalence rates reported in the extant literature, suggesting that prior research may overestimate use (see Van Dorn et al, 2012). …”

“…For all measures, responses were dichotomized to indicate use or non-use (Van Dorn et al, 2012; Desmarais et al, 2013). …”

Letter to the Editor: Critique of Bahorik et al. () – 'Under-reporting of drug use among individuals with schizophrenia: prevalence and predictors'

“…Finally, Bahorik and colleagues’ argument that self-report measures ‘ could considerably underestimate actual rates of use ’ in outpatient samples is not supported by contemporary research. Research on inpatient samples from the late 1980s and early 1990s showed under-reporting of drug use; however, more recent research concludes that self-report is an accurate approach to assessing drug use (Wolford et al 1999; Van Dorn et al 2012; Desmarais et al 2013). …”

“…In fact, biological tests add little incrementally to the accuracy of multi-modal assessment protocols (Wolford et al. 1999; Van Dorn et al 2012; Desmarais et al 2013). As Bahorik and colleagues note, ‘ much remains to be learned ’ about the reporting of drug use in this population; however, their framing of the research, sample selection, findings, and conclusions misconstrue the relationship between self-report and biological tests in the CATIE data.…”