Effects of Tirzepatide on Alcohol Intake in Patients Diagnosed With Schizophrenia and Alcohol Use Disorder

Glucagon-like peptide-1 receptor agonists (GLP-1RAs), approved for the treatment of type 2 diabetes and obesity, have shown promise as a novel treatment for alcohol use disorder (AUD). This study aims to investigate whether the Glucose-dependent Insulinotropic Polypeptide/GLP-1RA tirzepatide will reduce alcohol consumption in patients with a dual diagnosis of AUD and schizophrenia, a population in dire need of improved treatment options. To further investigate the neurobiological underpinnings of a potential dampening effect on alcohol consumption, functional magnetic resonance imaging (fMRI) brain scans will be applied. The key anticipated outcomes include: * decreased alcohol consumption and * reduced alcohol cue-induced brain activity in the GIP/GLP-1-treated patient group compared with the placebo group. To the best of the investigators knowledge, this has never been examined before.

The study is a randomised (1:1), double-blinded, placebo-controlled clinical trial including 26 weeks of treatment investigating whether tirzepatide vs placebo can reduce the number of heavy drinking days in patients with comorbid diagnoses of schizophrenia and AUD. The primary endpoint will be evaluated after 16 weeks of treatment. The study will conclude after a post-intervention follow-up 14 weeks after last treatment at week 40 of the study. 108 participants will be included. Alcohol consumption and secondary endpoints will be assessed at weeks 0, 4, 8, 12, 16, 20, 26, and 40, and all patients will be offered 6 sessions of supportive therapy, while participating in the study. The randomisation and administration of the weekly injections (tirzepatide/placebo) will be administered by an unblinded staff not involved in other trial activities. All patients will be blindfolded when receiving the injections. Eligible patients (n=50) will have an fMRI brain scan performed at baseline and in week 16. Blood tests for safety measures and secondary endpoint-measures will be performed at weeks 0, 16, 26, and 40.