SAN DIEGO — The Patient Health Questionnaire 9-item depression scale detected major depression in 29% of epilepsy patients, results from a large single-center study showed.
Moreover, 52% of patients who had scores consistent with major depression were not on antidepressant medications, Dr. Nicole A. Seminario reported in a poster session at the annual meetings of the American Epilepsy Society and the Canadian League Against Epilepsy.
“It's important to be able to identify those people,” she said in an interview. “This scale is nice because you can hand it out to your patients in the clinic, and it's not as time consuming as a lot of the other inventories.”
Adapted from the Prime-MD patient health questionnaire, the self-administered Patient Health Questionnaire 9-item depression scale (PHQ-9) was first described in psychiatric literature (Psychiatr. Ann. 2002;32:509–21). It has been validated in the general population, indicating a prevalence rate of 9.2% for a current depressive disorder and a prevalence rate of 3.8% for major depression.
Dr. Seminario and her associates used the survey to determine the prevalence of major depression in 229 patients seen at the epilepsy clinic of the University of California, Davis, between May and November of 2005, including those seen for the first time and those seen for follow-up visits.
The patients filled out the PHQ-9 in the waiting room. The mean age of patients was 41 years, and 51% were female.
The researchers defined major depression as having a PHQ-9 score of 10 or higher (based on a scale of 0–27), as has been previously recommended in the medical literature.
Of the 229 patients, 67 (29%) had PHQ-9 scores of 10 or higher, reported Dr. Seminario, of the department of neurology at the University of California, Davis. Of these 67 patients, 35 (52%) were not on antidepressant medications, which suggests that they were undertreated. In addition, the mean depression scores were significantly higher in survey respondents who were on antidepressants, compared with those who were not taking antidepressants.
Depression status did not vary by type of antiepileptic medication used.
Patients with nonepileptic seizures were more likely to have depression than were their counterparts with other forms—localization related, idiopathic generalized, symptomatic generalized, and undetermined—of epilepsy. There were no other significant differences in depression scores among any of the other epilepsy groups.
“Our findings suggest that depression has a stronger association with lack of seizure freedom rather than the burden of antiepileptic drugs,” the researchers wrote. “There was no difference in depression score between patients on various monotherapies suggesting that the depression scores did not relate to particular side effects of the antiepileptic medications.”