The Neurochemical Consequences of Music Therapy on Dementia Patients

As the incidence of dementia continues to rise, the need for an effective and non-invasive method of intervention has become increasingly imperative. Music therapy has exhibited these qualities in addition to relatively low implementation costs, therefore establishing itself as a promising means of therapeutic intervention. In this review, current research was investigated in order to determine its effectiveness and uncover the neurochemical mechanisms that lead to positive manifestations such as improved memory recall, increased social affiliation, increased motivation, and decreased anxiety. Music therapy has been found to improve several aspects of memory recall. One proposed mechanism involves temporal entrainment, during which the melodic structures present in music provide a framework for chunking information. Although entrainment's role in the treatment of motor defects has been thoroughly studied, its role in treating cognitive disorders is still relatively new. Musicians have also been shown to demonstrate extensive plastic changes; therefore, it is hypothesized that non-musicians may also glean some benefits from engaging in music. Social affiliation has been found to increase due to increases in endogenous oxytocin. Oxytocin has also been shown to strengthen hippocampal spike transmission, a promising outcome for Alzheimer's patients. An increase in motivation has also been found to occur due to music's ability to tap into the reward center of the brain. Dopaminergic transmission between the VTA, NAc and higher functioning regions such as the OFC and hypothalamus has been revealed. Additionally, relaxing music decreases stress levels and modifies associated autonomic processes, i.e. heart rate, blood pressure, and respiratory rate. On the contrary, stimulating music has been found to initiate sympathetic nervous system activity. This is thought to occur by either a reflexive brainstem response or stimulus interpretation by the amygdala.