The rate of psychiatric disorders in veterans undergoing intensive EEG monitoring is associated with symptom and performance invalidity

Abstract

Objective: To determine if the number of participants with psychiatric disorders increased in association with failures on symptom validity tests (SVTs) and a performance validity test (PVT) in Veterans admitted for evaluation of possible seizures. Method: The 254 participants were Veterans undergoing inpatient video-EEG monitoring for the diagnosis of possible seizures. DSM-IV psychiatric disorders were diagnosed with the SCID IV. Symptom exaggeration was assessed with the MMPI-2-RF and performance validity with the TOMM. Results: On the MMPI-2-RF, 27.6%–32.7% showed symptom exaggeration. Participants who exaggerated on the MMPI-2-RF were more often diagnosed with psychiatric disorders. The TOMM was failed by 15.4% of the sample. Participants who failed the TOMM were more often diagnosed with an Axis I disorder but not with a personality disorder. The MMPI-2-RF was invalid in more cases than the TOMM, but 7.9% of the sample generated a valid MMPI-2-RF and an invalid TOMM. Conclusions: The correlational design does not allow conclusions about cause and effect. The invalid groups may have had a higher rate of psychopathology. The number of participants with psychiatric disorders increased in association with symptom exaggeration and performance invalidity. Symptom exaggeration was more frequent than performance invalidity, but the TOMM made a unique contribution to identification of invalidity. The routine clinical use of SVTs and PVTs is supported. The results also suggest the need for caution in diagnosing psychiatric disorders when there is symptom exaggeration or performance invalidity, because diagnostic validity is dependent on the accuracy of symptom reporting.