[Experimental study on the tracking behaviour with a view to differentiating the effects of an antidepressant in various doses compared to placebo (author's transl)].

In a double-blind cross-over study 15 highly motivated, healthy male subjects (Ss), aged from 23 to 29 years, were given 200 mg and 400 mg p-methoxy-phenoxyaceticacid-diethylaminoethylamide-hydrochloride (mefexamide) and a placebo. On each of the three days the Ss were tested in different tracking devices and the integrated absolute error was measured in the tests of a duration of three hours each. Influences of practice, leading to unwanted and disturbing effects were excluded by a preceding period of four training sessions on different days. The main result of the investigation was that performance in tracking was ambivalent. The single dosage (200 mg mefexamide) caused small improvements in tracking in the range of about 5%. These differences from placebo partly could be determined to be significant at the level of 5% compared to placebo. The double dosage (400 mg mefexamide) deteriorated tracking performance significantly (5%-and partly 1%-level, two-tailed test) in the range of about 10% on the average. Differences in performance between the two dosages were correspondingly larger and could be determined at a higher level of significance, too.