The treatment of cognitive dysfunction in dementia: a multiple treatments meta-analysis

No cure is currently available for dementia; however, various treatments and interventions have been reported to be effective. The factors influencing the efficacy of dementia treatment have not been comprehensively evaluated. This study evaluated the factors influencing treatment effects on cognitive dysfunction in dementia by comparing the results obtained from a meta-analysis based on meta-regression. We searched for articles, clinical trials, and meta-analyses on the efficacy of pharmacotherapy or psychosocial treatment for dementia published between 2000 and 2016 in the MEDLINE/PubMed, Cochrane Library, SCOPUS, and Airiti Library databases. The 235 selected studies involved 44,854 patients with dementia (mainly vascular dementia, Alzheimer disease, and mild cognitive impairment). A preliminary random effects meta-analysis yielded a positive overall effect. The pooled standardized mean difference of the treatment effects on cognitive dysfunction was 0.439 (95% confidence interval 0.374, 0.504). The results of meta-regression showed that in young patients (beta = - 0.036, p value < 0.001) with vascular dementia (beta = 0.603, p value < 0.001), the efficacies of treatment 2 (symptomatic treatment for vascular dementia with piracetam, nimodipine, aniracetam, flunarizine, vinpocetine, hyperbaric oxygen, oxiracetam, or EGB761) and treatment 5 (treatment with other alternative therapies including acupuncture, premarin, statin, butylphthalide soft capsules, donepezil, huperzine A, and lithium treatment) were higher than those of other existing treatments for cognitive dysfunction (beta = 0.308 and 0.321, p values = 0.010 and < 0.001, respectively). The most effective intervention for dementia available is symptomatic treatment for vascular dementia. Antipsychotic treatment for dementia alleviates cognitive dysfunction less effectively than does symptomatic treatment. Alternative therapies are also effective at present. Further research on causes and very early diagnosis of Alzheimer disease is warranted.