Gabapentin in bipolar disorder: a placebo-controlled trial of adjunctive therapy. Gabapentin Bipolar Disorder Study Group.

OBJECTIVES: [corrected] To assess efficacy and safety of gabapentin in the treatment of bipolar disorder. METHODS: This was a double-blind, placebo-controlled trial of adjunctive gabapentin (dosed flexibly between 900 and 3,600 mg/day). Patients with a lifetime diagnosis of bipolar disorder (type I), and who were currently suffering from symptoms of either mania, hypomania or a mixed state despite ongoing therapy with lithium, valproate, or lithium and valproate in combination were eligible for inclusion. The primary efficacy measures were the baseline to endpoint change in total score on the Young Mania Rating Scale (YMRS) and the Hamilton Depression Rating Scale (HAM-D). RESULTS: Both treatment groups had a decrease in total YMRS from baseline to endpoint, but this decrease was significantly greater in the placebo group (-9) than the gabapentin group (-6) (p < 0.05). No difference between treatments was found for the total score on the HAM-D. Secondary efficacy measures were not different between treatment groups. More patients in the placebo group had changes made to their ongoing lithium therapy (n = 12) compared to the gabapentin group (n = 4). When these patients are removed from the efficacy analysis, the YMRS treatment difference still favors placebo, but is no longer statistically significant. Based on gabapentin plasma levels at termination, some patients did not take the study drug as prescribed. CONCLUSIONS: The findings of this study did not demonstrate that gabapentin is an effective adjunctive treatment when administered to outpatients with bipolar disorder.

Validity and reproducibility of a food frequency interview in a Multi-Cultural Epidemiology Study.

PURPOSE: There is limited support for the validity and reproducibility of dietary assessment in culturally diverse populations. The goal of this study was to evaluate the comparative validity and reproducibility of a Food Frequency Questionnaire (FFQ) used in the observational, multi-cultural Insulin Resistance Atherosclerosis Study (IRAS). METHODS: Women (n = 186) were approximately equally distributed by ethnicity from one urban center (African Americans and non-Hispanic whites) and one rural center (Hispanics and non-Hispanic whites). The IRAS FFQ was modified from the National Cancer Institute Health Habits and History Questionnaire to include ethnic and regional foods. Validity was assessed by comparing dietary values, including supplements, obtained from the FFQ to the average intake estimated from a series of 8 24-hour dietary recalls collected by telephone over the same 1-year period. Reproducibility was assessed among women who reported no change in their usual diet (n = 133) by comparing data from the original IRAS FFQ (in-person) with the FFQ administered for the validity study (two to four years later, by telephone). RESULTS: Correlation coefficients for validity were statistically significant for most nutrients (mean r = 0.62 urban non-Hispanic white, 0.61 rural non-Hispanic whites, 0.50 African American, 0.41 Hispanic) and did not differ among subgroups of obesity or diabetes status. The median correlation coefficient for the total sample was 0.49. Correlations were lower for women with less than 12 years of education (mean r = 0.30; median r = 0.25). The lower correlations among Hispanics was largely explained by the lower educational attainment in that sample. For reproducibility, the mean correlation for nutrients evaluated was r = 0.62 (median r = 0.63) and did not differ for subgroups. CONCLUSIONS: Although educational attainment must be considered, the IRAS FFQ appears to be reasonably valid and reliable in a diverse cohort.