Introduction N d 1 2 3 4 5 6 6 7 Methods Searching at MEDLINE (during April 2006, PubMed), LILACS (Latin American and Caribbean Health Science Literature: 40th edition, May 2001, the last research was performed in April 2006); Cochrane Library (issue 1, 2006); Dissertation Abstract (USA, during April 2006); ADEAR (Alzheimer's Disease Clinical Trials Database, until April 2006); National Research Register (1/2006); Current Controlled trials (the last research was performed in October 2005); PsychINFO Journal Articles (during the year of 2006); relevant web sites; and scanning of reference list of relevant articles. There were no language or publication restrictions. 8 Inclusion criteria The studies should be randomized; double-blind and controlled (with a control group and a treatment group). Studies should establish methodological procedures in the crossover or be conducted at the same time. In the case of being crossover, a washout period of at least 7 days was required. 9 Clinical trials should last for at least 1 month (4 weeks). Detailed description of the herbal product used. Neuropsychiatry symptoms progression should be measured with numerical score using the Assessment Scale (ADAS-noncog, range of score, 0–70), NPI (Neuropsychiatric Inventory, range of score 0–120), Clinical Global impression of change or Behavioral rating scale for Geriatric patients. The final score should be quantified using a combination of ADL and IADL methodological procedures. Exclusion criteria Jadad's measurement scale et al 8 10 All extraction and quality assessments were performed by at least two independent reviewers using standard forms developed for each review. Disagreements were documented and discussed with final decisions made by the principal reviewer. Results Salvia officinalis 11 Melissa officinalis 12 13 14 Table 1 Gingko biloba 15 Huperzia serrata 16 11 12 13 14 13 14 11 12 11 12 None of the studies evaluated the institutionalization rate or compared the active principle with the current therapies with Acetyl Cholinesterase Inhibitor or memantine. Discussion S. officinalis 11 M. officinalis 12 13 14 Gingko biloba 13 gingko G. bilob 17 H. serrata 16 12 13 M. officinalis 18 19 21 22 23 24 25 in vitro 26 27 28 Unticariae sinensis and Angelicae root Rehmannia glutinosa Cornus officinalis Dioscorea batatas Alisma orientale Poria cocos Paeonia suffruticosa Cinnamomum cassia Aconitum carmichaeli 29 30 13 14 Table 1 13 14 31 The use of herbal medicines in the treatment of AD should be compared with the pharmacological treatment currently in use. Such studies should include the identification of the active principle in order to improve the validation of the clinical trial. Further large-scale, multicenter studies are necessary to determine the effectiveness of these substances in the cognitive deterioration of AD. Until then, this review provides some evidence of the benefit of Melissa, Salvia, Yi-Gan San and BDW in the treatment of AD.