Abstracts

Rationale: Up to 30% of youth with epilepsy develop depression (Dunn, Austin 2004). Identification of risk-factors is important for early detection and management. Children with epilepsy who exhibit behavioral dyscontrol along with depression are at increased risk for suicide (Caplan, et al. 2005). However, it is unclear whether behavioral dyscontrol also increases risk for depression. The relationship between depression and executive function among children with epilepsy is not well understood but potentially clinically important. Our objective is to explore the predictive value of different aspects of executive functions on depressive symptoms in children with epilepsy.Methods: Clinical neuropsychological evaluations of 126 pediatric patients with epilepsy from the Children’s Hospital Boston Epilepsy Program were retrospectively reviewed. Stepwise multiple regression was used to evaluate demographic, cognitive, seizure and executive function variables as predictors of depressive symptoms. Anxiety symptoms were analyzed in parallel as a contrast to evaluate the relationship between executive functions and other aspects of emotional adjustment.Results: Mean age was 11.6±3.7 years; 55.6% were male, and average IQ was 82.9±17.0. Mean age of seizure onset was 4.4±3.7 years (17.8% generalized absence; 39.8% generalized other; 27% simple partial; 61% complex partial). Some patients experienced more than one seizure type. Average number of antiepileptic drugs at time of evaluation was 1.5±1.0. Twenty patients (16%) had previous epilepsy surgery. The BRIEF Behavioral Regulation Index (BRI) includes impulse control, emotional regulation, and shifting behaviors and accounted for 43.6% of the variance in depression symptoms (p=.000). In contrast, the BRI accounted for 6.8% of the variance in anxiety symptoms (p=.006); while this result is significant, the amount of symptom variance explained by the BRI is strikingly less for anxiety than depression. The BRIEF Metacognitive Index includes planning, organization, and working memory and was not a significant predictor of depression symptoms (p =.310). The demographic, cognitive, and seizure variables were not significant predictors of depression or anxiety.Conclusions: Poor behavioral regulation may be an important risk factor for depression in youth with epilepsy while metacognitive functions may not be related to mood problems. The predictive value of behavioral regulation on emotional adjustment is stronger for symptoms of depression than anxiety. These findings lend clues to the neurological basis of depression in epilepsy; behavioral regulatory functions are associated with medial frontal-subcortical circuits, in contrast to metacognitive aspects of executive functions which are mediated by the dorsolateral prefrontal cortex. Given the morbidity associated with comorbid epilepsy and depression, better appreciation of risk factors is important for preventive strategies. Prospective investigation of the relationship between executive function and depression in children with epilepsy is warranted.