Chinese herbal medicine for dementia &amp; related disorders: an evaluation of traditional and scientific evidence
Creators: name: May, Brian
Publisher: name: RMIT University
Year: 2024

description: This study evaluated the evidence for the use of Chinese Herbal Medicine (CHM) for dementia, in particular Alzheimer’s disease (AD), and for other disorders of age-related cognitive impairment, in the modern and classical literatures of Chinese medicine. <br><br>The modern literature included clinical trials using scientific methodologies and the expert recommendations for CHM practice found in contemporary clinical manuals (CCMs). Two systematic reviews of the clinical research literature for CHM (excluding Gingko biloba) were conducted. One for AD and Vascular Dementia (VaD) and one for Mild Cognitive Impairment (MCI) and Age Associated Memory Impairment (AAMI). <br><br>For AD and VaD, 14 articles satisfied all inclusion criteria and received scores of 3 or above on Jadad’s scale. Where possible, meta-analyses were conducted on common outcome measures. These suggested an overall benefit for the CHMs used but not necessarily any benefit in excess of other intervention. For MCI and AAMI, 12 articles reporting on 10 RCTs were included. Meta-analyses again suggested an overall benefit for these CHMs. The data for the test formulas used in the trials and their constituent herbs were coded and entered into Statistical Package for the Social Sciences (SPSS). When compared with the results derived from the CCMs, considerable disjunctions were found between the interventions recommended in CCMs and those that had received clinical research attention. <br><br>For the classical literature, two sources (680 and 1000 books respectively) that encompassed the scope of the classical literature were searched for herbal formulas and individual herbs that had been recorded for the clinical management of dementia and memory impairment. These were extracted to data bases for analysis.<br><br>A series of general categorisation criteria were developed for inclusion/exclusion of entries and to identify sub-groups. Rating systems were developed based on the DSM IV-TR criteria for dementia (including scores for memory impairment, ageing and symptoms such as aphasia) and on the Neuropsychiatric Inventory (NPI) to enable the location of entries in the classical literature that were more or less likely to have been references to conditions analogous to the modern conceptions of dementia. Ratings were undertaken by two raters working independently with disagreements being resolved by discussion. <br><br>It was found that analyses of both classical data sets produced similar sets of high frequency herbs overall, and similarities generally persisted when the data were progressively restricted according the categorisation criteria and ratings. Entries that could be considered probable instances of dementia were located and discussed. Herbs that satisfied the inclusion criteria and ratings were listed for further research as leads for drug discovery and also for use in clinical trials. Comparisons with the modern literature found both similarities and differences in the high frequency herbs and formulas. These were discussed.<br><br>In addition, this research aimed to make a contribution to the on-going development of evidence-based Chinese medicine by combining evidence from a range of sources to determine the state and level of the best available evidence for dementia and related disorders. It was envisaged that this method could be adapted and applied to other conditions.