A randomized single-blind trial of the therapeutic effects and safety of halved dose antipsychotics for treating relapse in patients with schizophrenia receiving high dose antipsychotic therapy

Halved dose of antipsychotics versus symptomatic treatment for relapse in patients with schizophrenia receiving high dose antipsychotic therapy: a randomized single blind trial - halved dose antipsychotic therapy

Status

Active, not recruiting

Phases

Unknown

Study type

Interventional

Source

JPRN

Registry ID

JPRN-UMIN000047785

Enrollment

Registered

2022-05-18

Start date

2021-01-04

Completion date

Unknown

Last updated

2026-06-29

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

schizophrenia

Interventions

Halve the amount of antipsychotics in patients receiving high-dose antipsychotics. If relapse is determined, the antipsychotic dose will be reduced. treatment with symptomatic treatment

Eligibility

Sex/Gender

All

Inclusion criteria

Inclusion criteria: Patients with schizophrenia receiving high-dose antipsychotic therapy

Exclusion criteria

Exclusion criteria: intellectual disability, neurodevelopmental disorders, organic, including symptomatic, mental disorder, long term depot antipsychotics within 3 months, electroconvulsive therapy within 6 months

Design outcomes

Primary

Measure	Time frame
the period from occurrence of relapse until relapse symptom improvement	—

Secondary

Measure	Time frame
Psychiatric symptoms will be evaluated according to the Positive and Negative Syndrome Scale (PANSS), and extrapyramidal symptoms (EPS) according to the Drug-induced Extra-pyramidal Symptoms Scale (DIEPSS) at baseline, at relapse, and after remission. All adverse events that appear will be evaluated.	—

Countries

Japan

Contacts

Public ContactRyota Ataniya

Edogawa hospital Department of Psychiatry

ryotaataniya@pbt.nir.jp4-7124-5511

Outcome results

None listed

Source: JPRN (via WHO ICTRP) · Data processed: Jul 3, 2026