Noben (idebenone) at a dose of 120 mg per day for six months was used in the treatment of 35 patients aged 60-86 years with Alzheimer's-type dementia, mixed dementia, and memory impairments not reaching the stage of dementia. Patients were assessed on the basis of data from somatic, neurological, and psychiatric investigations, as well as neuropsychological testing and a series of psychometric and other scales and tests, before and after treatment. Significant improvements in patients' conditions on the MMSE were seen in patients with mild and moderate dementia. Improvements in daily activities were obtained in 27% of patients. Neuropsychological investigations demonstrated improvements in short-term and long-term memory and attention, with improvements in speech functions, performance of kinesthetic, spatial, and dynamic praxis tests, and in visuospatial gnosis, thought, and writing. On the CGI scale, positive treatment effects were obtained in 37% of patients, while 48% of patients remained in a stable state.