A study of amnesia in homicide cases and forensic psychiatric experts' examination of such claims

Prevalence and Assessment of Malingering in Homicide Defendants Using the Mini-Mental State Examination and the Rey 15-Item Memory Test

This study surveyed malingering prevalence in pretrial homicide defendants and assessed the usefulness of the Mini-Mental State Examination (MMSE) and the Rey 15-Item Memory Test (FIT) in detecting malingering among them. Malingering prevalence was 17%. MMSE and FIT scores were positively correlated. The MMSE and FIT had modest positive predictive value (67% and 43%), but reasonably good negative predictive value (93% and 89%), for malingering. Overall, the MMSE outperformed the FIT, with no advantage to combined use of the MMSE and FIT over the MMSE. The widely used MMSE, traditionally a bedside test of cognition, may have a role in malingering assessment.

Evaluating amnesia for criminal behavior: a guide to remember

This article provides a guide that is important to remember in evaluating a criminal defendant's amnesia claim. Important concepts to understand regarding memory formation, memory systems, proposed causes of amnesia, reasons why amnesia claims may be true or false, and important strategies to implement as part of the evaluation process are reviewed. Structured assessment approaches are critical components of amnesia evaluations and generally require detailed questioning, review of collateral records, medical and neurologic workups, psychological testing, neuropsychological testing, and specific malingering assessments.

Lack of quality assurance in forensic psychiatry: false positive prevalence of antisocial personality disorder among norwegian inmates on preventive detention

Introduction

A Norwegian government publication (1) claims a prevalence of around 50% of Antisocial Personality Disorder (APD) in a small group of male detainees on preventive detention. The present study population is recruited from more or less the same population as those among whom a 50% prevalence of APD has been claimed (1). Norwegian forensic investigators rarely (17%) apply psychometric tools to confirm their clinical diagnosis (2).

Aims

To confirm the diagnosis of APD applying SCID axis II. Methods: Fifty six inmates were available at the prison. Twenty eight were willing to participate (50%). Two were excluded. Thus, 26 (46%) inmates participated. DSM IV, SCID axis II was applied.

Results

None of the 26/56 matched the APD criteria, mainly failing to fulfil the diagnosis of Conduct Disorder (CD) before the age of 15 years. All the inmates had a history of antisocial behaviour.

Conclusions

To explain the claim of around 50% APD in view of the present results, close to 100% APD should be found among the remaning thirty non-participating inmates. We consider this unlikely.

A diagnosis of APD based on the history of antisocial behaviour alone represents a pitfall. Lack of quality assurance could lead to false positive diagnosis. The need for a standardized approach and quality assurance in Norwegian forensic psychiatric evaluations seems nevessary to avoid false positive diagnosis.