BRECKENRIDGE, COLO. – Depression has an atypical presentation in people with epilepsy, but recognizing and treating depression can significantly improve quality of life for patients carrying the dual diagnoses, Lauren C. Frey, M.D., said at a conference on epilepsy syndromes sponsored by the University of Texas at San Antonio.
Findings from recent studies demonstrate that depression is a major driver of poor quality of life in patients with epilepsy. It also markedly increases their health care utilization, added Dr. Frey, a neurologist at the University of Colorado, Denver.
Preliminary evidence shows that antidepressant medication is safe and effective in epileptic patients, she continued.
Several years ago Andres M. Kanner, M.D., and colleagues at Rush Medical College, Chicago, first described a series of 97 patients with epilepsy considered by their treating neurologists to have depression sufficiently severe to warrant antidepressant medication. Of these 97 patients, 69 had atypical symptom patterns that didn't fulfill DSM criteria for a major depressive disorder or any other affective disorder. The absence of a definitive DSM diagnosis shouldn't put the brakes on appropriate treatment of these patients, Dr. Frey said.
Although these patients had some changes in sleep, appetite, and concentration, the most prominent manifestations of their depression were intermittent anhedonia, irritability, and poor tolerance of frustration. They also displayed mood lability, anxiety, and fatigue, with some symptom-free days.
Comorbid symptoms of depression and worry about seizures were the two strongest predictors of quality of life in a series of 115 patients with medically intractable epilepsy recently reported by David W. Loring, M.D., and coinvestigators at the University of Florida, Gainesville, and quoted by Dr. Frey.
In regression analysis, depressive symptoms as measured by the Beck Depression Inventory (BDI) and Seizure Worry, from the Epilepsy Foundation of America Concerns Index, together explained 61% of the variance in Quality of Life in Epilepsy (QOLIE-89) scores. No one of the other statistically significant predictors of QOLIE-89 score, including education level and age at seizure onset, explained more than 6% of the variation (Epilepsy Behav. 2004;5:976–80).
The adverse effect comorbid depression exerts on use of health care resources by epilepsy patients was underscored in a recent study by Joyce Cramer and colleagues at Yale University, New Haven. In their national postal survey of people with epilepsy, 443 respondents had no symptoms of depression on the widely used Centers for Epidemiologic Studies Depression Scale (CES-D), while 74 had mild to moderate depressive symptoms and 166 had severe symptoms.
People with epilepsy and comorbid mild to moderate depressive symptoms had twice as many visits to medical doctors in the past year, compared with nondepressed respondents. Those with severe depressive symptoms had four times as many visits (Epilepsy Behav. 2004;5:337–42).
The most disturbing survey finding, said Dr. Frey, was that a mere 47% of respondents with current symptoms of severe depression were on antidepressant medication. Complete resolution of depressive symptoms was achieved in 54% of the 100 patients on a mean dose of 108 mg/day of sertraline. That's a therapeutic success rate comparable to nonepileptic populations.
The main aim of the study, was to look at the safety of sertraline in an epileptic population, a valid concern because an earlier generation of antidepressants–the tricyclics–are known to lower the seizure threshold.
One patient's seizures were definitely worse on sertraline. Five had worse seizures, probably related to the drug; seizure frequency returned to baseline in all five cases upon upward adjustment of antiepileptic drug doses.