Secondary outcome measures are ( 1 ) change in severity of behavioural symptoms , as measured by the NPI-Q at 4 months ( to ensure antipsychotic reduction has not lead to worsening behavioural symptoms ) , and ( 2 ) proportion of people with HD who have had a reduction in antipsychotic dosage at 4 months for each strategy , compared to 4 months prior to enrolment ( to capture the possibility that both arms reduced antipsychotic use ) .