Current and future treatments for cognitive deficits in dementia.

In this article, we primarily focus on the treatment approaches currently marketed and in advanced stages of development for Alzheimer's disease (AD). Amyloid plaques and neurofibrillary tangles remain the pathologic hallmarks of AD, and much progress has been made in unraveling the molecular biology of these changes. In addition, there is also intense research into inflammatory and oxidative mechanisms as well as vascular and neurochemical alterations in AD. Therapies targeted at these mechanisms are discussed.

Efficacy and safety of St. John's wort for the treatment of major depression.

OBJECTIVE: Extracts of St. John's wort have been widely used in the treatment of depression. Our aim was to review information related to the efficacy and safety of St. John's wort as an antidepressant. DATA SOURCES: Primary and review articles were identified by a search of Medline (1960 to February 2000) and through secondary sources. STUDY SELECTION: All the articles identified from the data sources were evaluated and all relevant information was included in this review. The pharmacokinetics, mechanism of action, efficacy, side effects and drug interactions of St. John's wort have been examined in various studies. CONCLUSION: St. John's wort is a promising investigational antidepressant, but the data are not yet sufficient to accept hypericum as a first line antidepressant preparation for treatment of depression. Besides the need for dose standardization and adequate trial lengths, there is a need for studies in severely depressed patients and long-term studies to assess the risk of relapse and recurrence.

Current status of antioxidant therapy for Alzheimer's Disease.

Accumulating evidence from preclinical and clinical studies supports the hypothesis that oxidative stress may be associated with the onset and progression of Alzheimer's Disease (AD). Antioxidant therapies are being promoted in the lay press to enhance mental functions and delay cognitive losses with aging. An increasing number of physicians are also recommending antioxidant therapies, such as high dose vitamin E, for subjects with AD and other neurodegenerative disorders. High dose vitamin E, ginkgo biloba, and selegiline are three putative antioxidants that have been tested in randomized multicenter trial conditions in the US. This paper summarizes the oxidative stress hypothesis of AD and reviews the strengths and limitations of published antioxidant studies in AD in relation to the role of such therapies in practice.

Hippocampal abnormalities in depression.

A quantitative magnetic resonance imaging study of regional brain T1 spin-lattice relaxation times in 29 normal volunteers and in 20 patients with major depression revealed significantly shortened T1 relaxation times for the hippocampus in depressed patients. These differences were particularly prominent in elderly depressed patients. T1 relaxation times are reflective of the content and macromolecular environment of tissue water protons; shorter hippocampal T1 values may reflect differences in the content or organizational properties of hippocampal water protons. These findings are consistent with several lines of evidence that have implicated a role for the hippocampus in the regulation of mood and in the pathophysiology of the stress response, and they suggest that major depression may be associated with biophysical tissue changes in the aging hippocampus.