Antipsychotic Effects Similar in Schizophrenia Subgroups as General Population

The effects of antipsychotics among different subgroups of patients with schizophrenia are generally similar to the entire patient population, according to study results published in The Lancet Psychiatry.

Researchers from the Technical University of Munich in Germany searched publication databases through June 2021 for studies that concentrated on the effect of antipsychotic medications. The researchers stratified patients into 6 subgroups:

• Children and adolescents;
• Patients with a first-episode;
• Patients with prominent negative symptoms;
• Patients with comorbid substance use;
• Patients with treatment-resistant disease, and
• Older adult patients.

Participants in each subgroup groups were evaluated for medication side-effects.

A total of 537 randomized controlled trials conducted in North America (n=221), Europe (n=126), Asia (n=60), Africa (n=8), the Middle East (n=8), and multiple regions (n=101) were included in the systematic review and meta-analysis.

The total study population comprised 76,382 participants (34.9% women or girls; mean age, 37.3 [range, 7.9-80.2] years). Among the entire study population, aripiprazole (standardized mean difference [SMD], -0.39) and asenapine (SMD, -0.30) were favored over placebo; clozapine was favored over haloperidol (SMD, -0.47); risperidone was favored over cariprazine (SMD, 0.34); olanzapine was favored over asenapine (SMD, 0.23); and olanzapine was favored over haloperidol (SMD, 0.18).

Results of subgroup analyses are shown:

• Haloperidol was more effective than fluphenazine (SMD, 1.35) and aripiprazole (SMD, -0.39), and asenapine (SMD, -0.38) was more effective than placebo among children and adolescents;
• Clozapine was more effective than chlorpromazine (SMD, 0.75) or haloperidol (SMD, -0.19), and olanzapine was more effective than haloperidol (SMD, 0.27) among patients with treatment-resistant disease;
• Amisulpride was more effective than placebo (SMD, -0.86) and olanzapine was more effective than haloperidol (SMD, 0.45) among older adult patients;
• Olanzapine was more effective than amisulpride among patients with prominent negative symptoms (SMD, 0.39); and
• Olanzapine was more effective than haloperidol among patients with first-episode schizophrenia (SMD, 0.36).

Significant subgroup effects were observed for the cariprazine vs risperidone, chlorpromazine vs clozapine, and fluphenazine vs haloperidol comparisons (P <.05). All other comparisons affected the entire population or the subgroups in a similar manner.

The major limitation of this analysis was that not all studies defined subgroups using the same inclusion or exclusion criteria.

Study authors concluded, “[I]n the absence of clear subgroup differences, guideline makers and clinicians can apply the evidence found in meta-analyses of studies in the general population of patients with schizophrenia to their patients. Clinicians should also consider whether or not a drug is approved for that specific subgroup; only a few antipsychotics are licensed for children and adolescents and clozapine is the only approved drug for patients who are at risk of suicide.”

Disclosure: Multiple authors declared affiliations with industry. Please refer to the original article for a full list of disclosures.