In bulimia nervosa (BN), borderline personality disorder (BPD) and major depression (MDD) are frequently comorbid conditions. Executive function has been found to be impaired in BPD and MDD, but the impact of comorbidity on neuropsychological function has rarely been investigated.
To investigate neuropsychological function in BN with a focus on comorbid BPD and MDD.
One hundred forty-four medication-free female patients entering a study of psychological treatments for BN performed a brief battery of neuropsychological tests. Comorbid MDD and BPD were systematically identified using standard interviews. Neuropsychological test results were compared.
Forty-one subjects had comorbid BPD and 35 had comorbid MDD, while 15 had both. There was no effect of comorbid MDD, but there was a significant effect of BPD and a significant interaction between the diagnosis of MDD and BPD on executive tasks (trail making and Stroop). Thus, compared with subjects without BPD, subjects with BPD performed significantly worse on tests of executive function, while the group with both comorbidities performed even worse.
There appears to be an additive effect of BPD and MDD resulting in impaired executive neuropsychological function. Future studies on either disorder and on BN should examine and account for the effect of comorbidity.