Biased responding: a case series demonstrating a relationship between somatic symptoms and impaired recognition memory performance for traumatic brain injured individuals

Biased responding on the Sternberg Recognition Memory Test was observed in four patients with traumatic brain injury. None of these individuals met th e Diagnostic and Statistical Manual's (DSM-IV) criteria for malingering. In dividual recognition memory scores were high shortly after injury, declined to chance or below at the 6- and 12-month evaluations, and then showed sub stantial recovery by the 24-month evaluation. Recall memory performance act ually declined slightly across this same 2-year period. Recognition memory scores were related to the extent to which the patients endorsed somatic it ems on the Hamilton Rating Scale for Depression (HAM-D). Poor performance w as associated with high somatic scores. The relationship between memory and somatic scores on the HAM-D in this case series suggests that unconscious processes can influence memory performance and, because of this, that clini cians should not use such performance as a primary indicator of malingering . More importantly, biased responding and actual memory deficits may coexis t. This is indicated in the current cases by the failure of recall memory t o improve during the 2 years these patients were followed.