3. Suggestions for design of future study.

Methods	Allocation: randomised, with sequence generation and concealment of allocation clearly described Blindness: double, tested Duration: 12 months beyond end of intervention at least Raters: independent
Participants	People with antipsychotic‐induced tardive dyskinesiaa Age: any Sex: both History: any N = 300b
Interventions	1. Antipsychotic reduction/cessation (N = 150) vs antipsychotic maintenance (N = 150) OR 2. Specific antipsychotic (N = 150) vs other specific antipsychotic (N = 150)
Outcomes	Tardive dyskinesia: any clinically important improvement in tardive dyskinesia, any improvement, deteriorationc Adverse effects: no clinically significant extrapyramidal adverse effects ‐ any time periodc, use of any antiparkinsonism drugs, other important adverse events Leaving the study early Service outcomes: admitted, number of admissions, length of hospitalisation, contacts with psychiatric services Compliance with drugs Economic evaluations: cost‐effectiveness, cost‐benefit General state: relapse, frequency and intensity of minor and major exacerbations Social confidence, social inclusion, social networks, or personalised quality of life: binary measure Distress among relatives: binary measure Burden on family: binary measure
Notes	aThis could be diagnosed by clinical decision. If funds were permitting all participants could be screened using operational criteria, otherwise a random sample should suffice. bSize of study with sufficient power to highlight about a 10% difference between groups for primary outcome. cPrimary outcome. The same applies to the measure of primary outcome as for diagnosis. Not everyone may need to have operational criteria applied if clinical impression is proved to be accurate.