Apathy is a common, early, and disabling symptom in dementias and mild behavioural impairment such as Alzheimer's disease (AD) and is characterized by lack of interest and enthusiasm. Both repetitive transcranial magnetic stimulation (rTMS), a form of non-invasive brain stimulation, and methylphenidate, a medication, have been shown to improve apathy. This pilot study will investigate rTMS as a treatment for apathy in neurocognitive disorders and mild behavioural impairment in individuals receiving methylphenidate and individuals not receiving medication for apathy.