More people are presenting with mild cognitive impairment (MCI), frequently a precursor to dementia, but we do not know how to reduce deterioration.
To systematically review randomised controlled trials (RCTs) evaluating the effects of any intervention for MCI on cognitive, neuropsychiatric, functional, global outcomes, life quality or incident dementia.
We reviewed 41 studies fitting predetermined criteria, assessed validity using a checklist, calculated standardised outcomes and prioritised primary outcome findings in placebo-controlled studies.
The strongest evidence was that cholinesterase inhibitors did not reduce incident dementia. Cognition improved in single trials of: a heterogeneous psychological group intervention over 6 months; piribedil, a dopamine agonist over 3 months; and donepezil over 48 weeks. Nicotine improved attention over 6 months. There was equivocal evidence that Huannao Yicong improved cognition and social functioning.
There was no replicated evidence that any intervention was effective. Cholinesterase inhibitors and rofecoxib are ineffective in preventing dementia. Further good-quality RCTs are needed and preliminary evidence suggests these should include trials of psychological group interventions and piribedil.
Declarations of interest
C.L. has received grant support (research or continuing medical education) from NIMH, NIA, Associated Jewish Federation of Baltimore, Weinberg Foundation, Forest, GlaxoSmithKline, Eisai, Pfizer, AstraZeneca, Lilly, Ortho-McNeil, Bristol-Myers Squibb, Novartis, National Football League (NFL), Elan, Functional Neuromodulation; and has been a consultant/advisor to AstraZeneca, GlaxoSmithKline, Eisai, Novartis, Forest, Supernus, Adlyfe, Takeda, Wyeth, Lundbeck, Merz, Lilly, Pfizer, Genentech, Elan, NFL Players Association, NFL Benefits Office, Avanir, Zinfandel, Bristol-Myers Squibb; and received honorarium or travel support from Pfizer, Forest, GlaxoSmithKline, Health Monitor.