DEPRESSION IN TEMPORAL-LOBE EPILEPSY - INTERACTION BETWEEN LATERALITYOF LESION AND WISCONSIN-CARD-SORT PERFORMANCE

The nature and specificity of the relationship between laterality of t emporal lobe epilepsy (TLE) and Wisconsin Card Sort Test (WCST) persev erative response (PR) level on self-report of mood state was examined in 123 left hemisphere-dominant patients with invasively verified epil epsy of left (n = 62) or right (n = 61) temporal lobe origin, There we re no overall significant differences between the left- and right-TLE groups on depression indices or number of WCST PRs. As predicted, a si gnificant interaction between laterality of TLE and PR level was obser ved. Among left-TLE patients, depressed mood was associated with the h ighest PR levels (30+), and these patients endorsed significantly more depressive symptoms than equally perseverative right-TLE patients. Am ong right-TLE patients, depressed mood was unexpectedly found to be as sociated with good WCST performance (i.e., PR <10), and these patients endorsed more depressive symptoms than the corresponding left-TLE gro up. Findings were specific to the WCST and were not seen when performa nce on two control tasks (Judgement of Line Orientation and Visual Nam ing) were examined. Results are discussed within the framework of curr ent models of mood state.