An 8-week, rater-blinded, real-world observational study to investigate the benefits of pharmacogenetics-based pharmacotherapy in patients suffering from schizophrenia.

This study, conducted at the Shanghai Mental Health Center, aims to compare changes in treatment efficacy and the frequency and severity of adverse reactions in patients with schizophrenia who have experienced treatment failure, before and after implementing a pharmacogenomics-based precision medication guidance strategy. The research is set in real-world conditions, without a predetermined treatment regimen for participants; instead, medication optimization is guided by pharmacogenomic testing results. Following the receipt of precision medication recommendations for each participant, the study physicians optimize the treatment regimen based on these recommendations and their clinical expertise. Optimization may involve adjusting the dose of current medications (if the existing regimen is largely suitable), switching medications (in cases of inappropriate treatment), or modifying the dose or replacing one of the combined medications (to manage drug-drug interactions). The rationality of the medication regimen will be assessed at the end of weeks 4 and 8, with additional recommendations provided as needed. Treatment effectiveness and safety will be evaluated during follow-up visits at these intervals. A total of 400 patients are planned to be included in the study.

Inclusion Criteria:

1. Suffer from schizophrenia (as assessed in agreement with ICD-11 criteria).

2. Age between ≥18 and <65 years.

3. Currently receiving inpatient or outpatient psychiatric treatment.

4. Experienced any of the following suboptimal treatment conditions while receiving antipsychotic medication within the therapeutic dosage range:

   1. Standard antipsychotic treatment for more than 2 weeks with the occurrence of drug-induced adverse effects requiring dose adjustment or a switch of medication.
   2. Antipsychotic treatment within the therapeutic dosage range for more than 4 weeks, with the presence of at least two items of the Positive and Negative Syndrome Scale (PANSS) (P1, P2, P3, N1, N4, N6, G5, and G9) score ≥4, or a total PANSS score >70, or a CGI-S score ≥4.
   3. Other situations where a change in medication is deemed necessary, as assessed by senior clinical physicians.

5. Understand the study requirements and provide written informed consent to participate; a signed and dated informed consent form (ICF) will be obtained from each patient before participation in the study.

Exclusion Criteria:

1. Presence of organic brain disease or a severe and/or unstable physical condition.
2. Substance abuse or dependence within the past 6 months or currently.
3. Presence of elevated levels of agitation, impulsivity, or risk of self-injury or suicide.
4. Pregnant or breastfeeding women.
5. The presence of any other conditions that may render the individual ineligible for participation in this clinical trial.

The study population includes outpatients or inpatients receiving treatment at the Shanghai Mental Health Center in Shanghai, China