Perrotta Integrative Clinical Interviews-3 (PICI-3): Development, regulation, updation, and validation of the psychometric instrument for the identification of functional and dysfunctional personality traits and diagnosis of psychopathological disorders, for children (8–10 years), preadolescents (11–13 years), adolescents (14–18 years), adults (19–69 years), and elders (70–90 years)

The Perrotta Integrative Clinical Interview, second version (PICI-2) requires structural and functional updates, based on clinical and academic experience, especially in terms of functional traits and interpretation of psychopathological disorders. The Perrotta Integrative Clinical Interviews-3 (PICI-3) was created and structured into four sections, dedicated to dysfunctional traits in children and pre-adolescents (PICI-C-3, 8–13 years) and in adolescents, adults, and the elderly (PICI-TA-3, 14–90 years), to common secondary disorders (PICI-DS-3, 8–90 years) and functional traits (PICI-FT-3, 8–90 years), with the identification of all functional elements and structural aspects of personality according to the model underlying the PICI (IPM). Selecting 1732 subjects, between 8 and 90 years old, the statistical analysis showed that the psychometric test has a well-defined and stable construct, with the variables well represented and positively correlated with other constructs already validated. In particular: (a) the PICI-TA-3 (Section A) was compared with the Minnesota Multiphasic Personality Inventory-2-Restructured Form (MMPI-2-RF), obtaining 99.3% compatibility of results, with a Pearson's coefficient (R) of 0.999 and p < 0.001; (b) the PICI-C-3 (Section B) was compared with the Child Behavior Checklist (CBCL), obtaining 94.1% compatibility of results, with a Pearson coefficient (R) of 0.969 and p < 0.001; (c) the PICI-FT-3 (Section D) was compared with the Big Five Personality Test (Big5), obtaining 89.4% compatibility of results, with a Pearson coefficient (R) of 0.797 and p < 0.001. The PICI-3 is a valid, efficient, and effective psychometric tool to identify the functioning or dysfunction of personality traits for psychopathological diagnosis.