Abstracts

Rationale: Psychiatric and neurodevelopmental spectrum disorders (PD & NSD) occur more commonly in people with epilepsy than in the general population. Most population-based studies focus simply on the relative frequencies of these disorders. Little is known about clinical characteristics of epilepsy that might distinguish epilepsy patients most and least likely to have these disorders and on the association between PDs and NSDs themselves in people with epilepsy. Methods: In a community-based cohort study of young people recruited at and actively followed since their initial diagnosis of epilepsy we examined the reported diagnoses of PD and NSD with respect to sex, age at onset and age at interview, type of epilepsy, intelligence, and measures of seizure control based on follow-up calls made 3-4 times per year, accumulated medical records, and an additional interview performed ~9-years after study entry. Results: Of 501 participating in the 9-y interview, 247 (49.3%) were female. The average age at onset was 5.8y (SD=4.0) and at 9y interview 15.3y (SD=4.2). One or more PDs was reported in 152 (30.3%) including depression (N=67), anxiety (N=25), bipolar disorder (N=6), ADHD (N=104), OCD (N=14), conduct disorder (CD, N=22), ODD (n=5) and schizophrenia (N=2) with 57 (11.4%) having multiple PDs. One or more NSDs was reported in 209 (41.7%) including delay (N=160), language problem (N=112), dyslexia (N=14), learning disorder (N=135), and autism (N=26). Multiple NSDs were reported in N=145. PDs occurred in 58 (19.9%) without and 94 (45.0%) with NSDs (p<0.0001). Overall, PDs were not strongly correlated with patient and epilepsy features with the exception of age at interview (<10y, (15.8%), 10-14y (26.7%), 15-19y (35.5%), 20 y (39.5%), p<0.0001). By contrast, most patient and epilepsy features were strongly correlated with NSDs. Depression was not associated with NSDs overall and was only weakly associated with dyslexia (p=0.03). By contrast, ADHD was strongly associated with NSDs overall and each one individually (0.0001< p <0.02). CD and anxiety were associated with some but not all NSDs. In 383 subjects with IQs > 80, 108 (28.2%) had >1 PD, and 97 (25.3%) had >1 NSD. In this subgroup, PDs were present in 19.6% without and 53.6% with NSDs (p<0.0001). Conclusions: Our findings suggest that some of the associations between epilepsy and psychiatric disorders seen in the literature may be mediated through cognitive and developmental disorders which themselves are strongly associated with epilepsy, particularly in children. This does not appear to be the case, however, for depression. Further research in the area of psychiatric co-morbidity in epilepsy should incorporate assessment of cognitive function and presence of NSDs in order to advance our understanding of how and why these various disorders co-occur together. Funded by NIH-NINDS grant R37-NS31146