Table 2. Comparison of the Zuckerman-Kuhlman Personality Questionnaire (ZKPQ) scales’ scores between the “healthy” participant (HS, N=475), the medical patient (MP, N=619), the psychiatric patient (PP, N=177) and the opiate addicts (OA, N=191) samples.

(1) Numbers indicate that each specific group differs significantly at least at a 0.01 level from the group indicated based on Bonferroni post-hoc tests. (2) Cohen’s ds were calculated considering the opiate addict sample as the treatment group and the healthy participant sample as the comparison group