Validity and Consistency of Self-Reports Regarding Substance Use in General Research Volunteers, Including Regular Cannabis Users and Schizophrenia Patients

Abstract

This study investigated the validity of self-reports of substance use in 69 low-level substance users from the general community of Perth, Australia, volunteering for electrophysiological research, between 2002 and 2003. The participants included regular cannabis users and schizophrenia patients. Self-reports of recent use (last 24 hours) highly agreed with urine screen results (kappa = 0.91). Self-reports of past use (lifetime and last 12 months) had poor-moderate consistency based on correlations among dependence (measured with SDS, FTND, SMAST, CAGE), frequency, and use duration. Therefore, under some conditions, self-reports are valid for recent use and only moderately consistent for past substance use in general research participants.

Keywords:

• general research
• low-level substance use
• self-report validity and consistency

Additional information

Notes on contributors

Karina K. Kedzior

Karina K. Kedzior is a physiologist who completed a doctorate in clinical neurosciences at the University of Western Australia in Perth, Australia in 2004. Currently she is a postdoctoral fellow at the Institute of Psychology, University of Bremen, Germany funded by the Hanse Institute for Advanced Studies (Hanse-Wissenschaftskolleg), Delmenhorst, Germany. She is interested in physiology and psychology of schizophrenia and cannabis misuse.

Johanna C. Badcock

Johanna C. Badcock is a Specialist Clinical Psychologist (Research) at the Centre for Clinical Research in Neuropsychiatry, Graylands Hospital, Perth, Australia. Dr. Badcock's training includes both experimental and clinical psychology; her current research focus is the cognitive basis of auditory hallucinations.

Mathew T. Martin-Iverson

Mathew T. Martin-Iverson is an Associate Professor at the School of Medicine and Pharmacology, University of Western Australia, and the Centre for Clinical Research in Neuropsychiatry, Graylands Hospital, Perth, Australia. His research interests include neurobiology of schizophrenia and substance use.