Experts' Failure to Consider the Negative Predictive Power of Symptom Validity Tests

Area of Science:

• Psychology
• Clinical Psychology
• Forensic Psychology

Background:

• Symptom validity tests (SVTs) are crucial for distinguishing genuine from feigned symptoms in clinical evaluations.
• A non-deviant SVT score ideally should reduce suspicion of malingering.
• The stereotypical
• antisocial
• profile of feigning in the DSM may bias clinicians' judgments.

Purpose of the Study:

• To investigate whether non-deviant SVT scores effectively reduce suspicion of feigning among psychology students and clinical experts.
• To assess the impact of educating participants on the limitations of DSM typologies and the utility of SVTs.

Main Methods:

• Four studies were conducted involving psychology students and clinical experts.
• Participants evaluated hypothetical cases with information presented incrementally, including non-deviant SVT outcomes.
• Suspicion of feigning and confidence in judgment were measured after each information step.

Main Results:

• Neither students nor experts significantly lowered their suspicion of feigning in response to non-deviant SVT scores.
• Suspicion rates remained around the midpoint of the scale, indicating persistent doubt.
• Educational interventions about SVT interpretation and DSM typologies did not alter these judgments.

Conclusions:

• Psychology students and clinical experts face challenges in correctly interpreting non-deviant SVT scores.
• This difficulty may stem from biases related to stereotypical patient profiles and a misunderstanding of the negative predictive power of SVTs.
• Improved training on SVT interpretation is needed to enhance diagnostic accuracy and reduce unwarranted suspicion of feigning.