Forensic-clinical Interview: Reliability and Validity for the Evaluation of Psychological Injury

Forensic evaluation of psychological injury involves the use of a multimethod approximation i.e., a psychometric instrument, normally the MMPI-2, and a clinical interview. In terms of the clinical interview, the traditional clinical interview (e.g., SCID) is not valid for forensic settings as it does not fulfil the triple objective of forensic evaluation: diagnosis of psychological injury in terms of Post Traumatic Stress Disorder (PTSD), a differential diagnosis of feigning, and establishing a causal relationship between allegations of intimate partner violence (IPV) and psychological injury. To meet this requirement, Arce and Fariña (2001) created the forensic-clinical interview based on two techniques that do not contaminate the contents i.e., reinstating the contexts and free recall, and a methodic categorical system of contents analysis for the diagnosis of psychological injury and a differential diagnosis of feigning. The reliability and validity of the forensic-clinical interview designed for the forensic evaluation of psychological injury was assessed in 51 genuine cases of (IPV) and 54 mock victims of IPV who were evaluated using a forensic-clinical interview and the MMPI-2. The result revealed that the forensic-clinical interview was a reliable instrument (α = .85 for diagnostic criteria of psychological injury, and α = .744 for feigning strategies). Moreover, the results corroborated the predictive validity (the diagnosis of PTSD was similar to the expected rate); the convergence validity (the diagnosis of PTSD in the interview strongly correlated with the Pk Scale of the MMPI-2), and discriminant validity (the diagnosis of PTSD in the interview did not correlate with the Pk Scale in feigners). The feigning strategies (differential diagnosis) also showed convergent validity (high correlation with the Scales and indices of the MMPI2 for the measure of feigning) and discriminant validity (no genuine victim was classified as a feigner). Notwithstanding, feigning strategies failed to correctly classify all of the feigners indicating they must be complemented with other measures (multimethod approximation) to meet the requirements of forensic settings.