[Differential pharmacologic therapy of generalized anxiety disorders--results of a study with 30 individual case...

In pharmacotherapy of generalized anxiety disorders (GAD) different psychopharmacological agents (neuroleptics, diazepines, antidepressants) proved to be effective. However, there is a lack of predictors of therapeutic response. The present study was designed to address this question in 30 patients with treatment refractory GAD (12 male, 18 female). Amitriptyline 30 mg/d, flupentixol 1.5 mg/d, clotiazepam 15 mg/d, and placebo were administered double-blind and randomly. Each agent was given 4 times for one week. To avoid carry-over effects, all treatment weeks were interrupted by one week's wash-out periods. Thus each single-case experiment comprised 31 weeks. Primary efficacy criterion was Hamilton total score at the end of each treatment week. Statistical analysis (U-test) showed that in 19 patients one agent was significantly (p < 0.05) superior to the other substances (clotiazepam n = 11, flupentixol n = 3, amitriptyline n = 5). Placebo was not superior in any of these 30 patients. There was no significant difference between the drugs in 11 patients. However, metaanalysis showed that in chronic GAD, by means of single-case experiments, differences in efficacy between different drugs can be found (p < 0.01). ANOVA showed no drug x time interaction.