Background: Progressive ageing-related processes of deteriorating cognition, such as Alzheimer´s disease, present as both cognitive and neuropsychiatric symptoms. Insufficient effects and severe adverse effects of medications have led to increasing interest in non-pharmacological treatments. Music-based therapies have been accepted in guidelines as supplementary treatment of dementia. Yet, optimal implementation has not been defined and evidence for symptom-specific effectiveness of music is still contradictory. 

Material and Methods: We analysed all (n=55) randomized controlled trials registered in PubMed database  investigating the effects of music on neuropsychiatric symptoms of dementia. Positive outcome was defined as superiority of music over standard care or non-musical intervention. Negative outcome was defined as lack of effect compared to standard care. 

Results: The trials applied both active and passive interventions, i.e. various types of physical participation in music making or mere music listening. The outcomes included behavioural and psychological symptoms of dementia (BPSD) en bloc, or specifically depression, agitation, anxiety or apathy. Music-based interventions resulted in positive outcome in 70%, 45%, 42% or 35% of interventions measuring BPSD, anxiety, depression or agitation, respectively. Negative outcome was obtained in good fourth of the interventions measuring BPSD, depression or agitation. 

Conclusions: The evidence for beneficial effects of music is firmest for unspecified BPSD or depression, moderate for agitation and anxiety, weak for aggressiveness and very weak for apathy. Mixed results may be due to heterogeneity in study design, clinical scales or make-up of patient cohorts.