Correlation Between Cognitive Function and Relapse of Schizophrenia Regarding Dose Reduction

We attempted to reduce the dose of antipsychotics to ≤1000-mg chlorpromazine eq./day. The dose was gradually reduced at a rate of ≤50-mg chlorpromazine eq./week, and the reduction was discontinued if the subjects relapsed. The differences in baseline cognitive function were analyzed between the patients with no relapse and relapse groups.

• reduction of risperidone, haloperidol, olanzapine, quetiapine, aripiprazole, paliperidone, levomepromazine, perphenazine (Drug)

Primary outcomes

• Number of Participants With Relapse [One year after the baseline cognitive function test or three months after the end of dose reduction, whichever came first.]: The definition of relapse is as follows 1.50% or greater increase in total DIEPSS score, 2. an increase in the total PANSS score of 25% or more from baseline, 3. deliberate self-injury, 4. emergence of clinically significant suicidal ideation, 5. violent behavior resulting in clinically significant injury to another person or property damage.

Sex: All, ages: 20 Years to 70 Years

Inclusion Criteria:

* inpatients with a diagnosis of schizophrenia, and
* those in the chronic phase receiving mean daily antipsychotic doses exceeding 1000-mg chlorpromazine eq./day.

Exclusion Criteria:

* mental retardation,
* substance abuse or dependence,
* a history of major head trauma,
* serious medical or neurological disorders, or
* depot antipsychotic injections within the previous 3 months and electroconvulsive therapy within the previous 6 months

Participant flow

Outcome results

• Number of Participants With Relapse (Primary), Count of participants, Participants: Dose Reduction 130

Adverse events

Other adverse events by term

• Takahashi Tadashi, Study chair, Okada hospital
• Mikiro Saito, Study chair, Okada hospital