The therapeutic efficacy and safety of oxiracetam (ISF 2522), a new nootropic cyclic GABA derivative, were investigated in a double-blind, placebo-controlled study in 40 patients with organic brain syndrome in late life. The psychopathology was characterized by memory deficits, intellectual dysfunction, lack of drive, and disturbance of affectivity. Patients were randomly assigned to a 4-week treatment with either 2 X 400 mg oxiracetam capsules t.i.d. or identical placebo capsules in the same dosing schedule. Evaluation of the psychopathology and side effects was carried out at weeks 0, 1 and 4; laboratory tests (hematology, blood chemistry and urinalysis), a battery of psychometric tests and quantitative EEG investigations were done at weeks 0 and 4. In the oxiracetam group a slight but significant improvement in global symptomatology was observed within 1 week, with further improvement after 4 weeks. In the placebo group, an improvement was seen only in the 4th week. Evaluation of the detailed psychopathology by means of the Sandoz clinical assessment geriatric scale (SCAG) showed in the oxiracetam group significant improvements in loss of appetite and vertigo after 1 week and in short-term memory, anxiety, emotional lability, fatigue, loss of appetite and vertigo after 4 weeks. In contrast, not a single item improved significantly during placebo treatment. Although the differences in SCAG scores between the two groups failed to reach statistical significance, the overall trend towards improvement was significantly better in the oxiracetam group. The tolerability of the drug was good.(ABSTRACT TRUNCATED AT 250 WORDS)