| What patient personality characteristics contribute to substance abuse treatment outcome? This study utilized data collected from a substance abuse treatment sample to explore the relationship between personality characteristics as measured by the Minnesota Multiphasic Personality Inventory-2 (MMPI-2) Personality Psychopathology Five (PSY-5) and substance abuse treatment outcome. The main research questioned the differences between treatment outcome groups (Completed, Left Against Medical Advice, and Referred) and the MMPI-2 PSY-5 Scales when administered during the first month of treatment. Five hypotheses were generated for each of the PSY-5 scales and their relationship to substance abuse treatment outcome. The PSY-5 scales measure Aggressivness, Psychoticism, Disconstraint, Negative Emotionality-Neuroticism, and Introversion-Low Positive Emotionality. All five scales were hypothesized to exhibit a significant relationship with substance abuse treatment outcome. A total of 261 participants from a substance abuse treatment sample were administered the MMPI-2 and a demographic questionnaire between 2 and 4 weeks of admission. MANOVA and ANOVA analyses yielded nonsignificant differences between and relationships among the PSY-5 personality characteristics and substance abuse treatment outcome. ANOVA and descriptive analyses conducted on the demographic variables revealed a significant positive relationship between education level and treatment outcome. Multiple regression conducted on the PSY-5 scales using the [MMPI-2] normative sample and this substance abuse sample indicated significantly higher scores on Psychoticism, Constraint, Negative Emotionality-Neuroticism, and Introversion-Low Positive Emotionality compared with a normal population. These results suggest that the MMPI-2 PSY-5 may not be a valid predictor of personality characteristics in relation to treatment outcome. Further PSY-5 testing on various demographic and clinical samples as well as additional considerations for exploring MMPI-2 personality differences and effects on substance abuse treatment are discussed. |
