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

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 α-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.