Personality characteristics of drug-dependent offenders

Abstract

The purpose of the study was to investigate whether personality questionnaires could differentiate significantly between drug dependent and non-dependent prisoners. The subjects were 340 Icelandic prisoners who were serving sentences for various offences. The psychological tests administered were the Eysenck Personality Questionnaire (EPQ), the Gough Socialisation Scale, and self-deception (SDQ) and other-deception (ODQ) questionnaires. Drug dependency was defined on the basis of regular illicit drug use during the previous 6 months (that is, weekly or more frequent consumption) and an experience with intravenous drug use. The 43 (13%) drug-dependent subjects scored significantly lower than the other prisoners on the Gough Socialisation Scale and the ODQ and SDQ, and significantly higher on the EPQ Psychoticism, Neuroticism, and Addiction Scales. However, when socially desirable responding (that is, the ODQ and SDQ scores) was controlled for by an analysis of covariance, only the Gough Socialisation Scale differentiated significantly between the two groups. It is concluded that drug dependency is significantly associated with signs of personality disorder, independently of social desirability. In addition, social desirability is negatively correlated with drug dependency in its own right. The implications of these findings are discussed. Another finding was that the drug-dependent subjects were significantly more likely to have committed property offences than the other prisoners, and they much more commonly reported having been under the influence of illicit drugs when committing the offence for which they were serving a prison sentence.