Processes of change assessment in heroin addicts following the Prochaska and DiClemente transtheoretical model.

Abstract

The processes of change dimension of Prochaska and DiClemente's transtheoretical model of change is tested in a sample of opiate addicts for the first time. A self-report (The Processes of Change Inventory for Opiate Addicts, PCI-OA) designed to assess the frequency of processes of change was administered in a sample of 178 heroin addicts in order to study its reliability, validity and discriminative efficiency. An alpha-reliability coefficient of 0.87 was obtained. A principal component analysis of the measure revealed a three-component solution which accounted for 34% of the variance: 'contemplation and preparation processes', 'processes of action', and 'processes of the final part of the action phase and maintenance'. Comparisons between abstinent and non-abstinent subjects revealed significant differences (P < 0.0001) in two of the ten processes considered: counterconditioning and stimulus control. A stepwise discriminant analysis yielded a linear combination of eight processes that correctly identified 78% of the total sample. Theoretical and clinical implications of the results are discussed, suggesting that the PCI-OA can be considered as a useful self-report instrument for identifying which processes of change are being used by a specific opiate-dependent patient.