OBJECTIVETo observe the clinical effectiveness and safety of Tiantai No. 1 (TT1) in treating mild cognitive impairment (MCI).

METHODSWith randomized double-blinded method adopted, the 128 MCI patients, selected according to the commonly accepted standard for MCI diagnosis, were assigned to 2 groups, the treatment group (65 cases) treated with TT1 and the control group (63 cases) treated with placebo for six months. Besides, a normal control group with 30 healthy elders was set up. Changes of comprehensive cognitive function, instant memory, short-term memory, calculation ability, orientating ability of time and space, language understanding ability as well as Chinese medicine syndromes before and after treatment were observed and compared.

RESULTSThe cognitive function of MCI patients was significantly lower than that of healthy elders (P<0.01). The comprehensive cognitive function, and all the above-mentioned abilities were significantly improved (P<0.05, P<0.01) in the TT1 treated group after treatment, with an effect significantly better than that in the placebo treated group (P<0.01). Overall evaluation of effect and safety suggested that the clinical effectiveness index (CEI) of TT1 was notably higher than that of the placebo. And it was found in one-year follow-up that the incidence of developing to Alzheimer's disease (AD) in the treatment group was strikingly lower than that in the control group (P<0.01).

CONCLUSIONTT1 can significantly improve the cognitive function of MCI patients, and reduce their incidence of developing to AD.