The aim of this sequential randomized controlled experimental design study is to develop an aggression care bundle approach in psychiatric care for patients with psychotic disorders, to use it in a psychiatric clinic, and to evaluate its results. The hypotheses it aims to test are as follows:

1. The aggression management care bundle applied to patients with psychotic disorders in a psychiatric clinic will reduce the risk of developing aggression.
2. The number of aggressive events in the patient group to whom the aggression management care bundle is applied will be less than the control group receiving routine care.
3. The use of restrictive aggression management techniques in the clinic will decrease.
4. The clinical compliance rate of the developed aggression management care bundle will be 95% and above.

Psychopathology plays an important role in the emergence of aggression. Having a diagnosis of psychotic disorder or schizophrenia is an important psychopathology that leads to aggression. For these reasons, aggression and how to manage it is an ongoing problem in psychiatric clinics. The prevalence of aggressive behavior in psychiatric wards varies between 8-76%. The prevalence of aggression in schizophrenia patients is stated as 33.3%. This aggression can be verbal, directed towards objects/spaces, towards oneself or physical aggression towards others. Healthcare professionals in psychiatric wards are exposed to these aggressive events carried out by patients. It is reported that 25-85% of healthcare professionals working in psychiatric wards are exposed to aggressive events; the prevalence of aggression towards nurses varies between 11.4-97.6%. Over the years, some methods have been developed and used to manage aggression in psychiatric wards. Chemical and mechanical restraint and seclusion methods are still the leading methods used. There is a need for alternative and evidence-based interventions based on therapeutic nursing approaches to manage aggression in psychiatric wards, which can be easily adopted and implemented in the clinic. Therefore, it was aimed to develop and use the "care bundle" approach, which has been shown to improve patient outcomes in the literature, for aggression management in psychiatric wards. Care bundles are care tools that target a specific patient population, consist of 3-5 evidence-based approaches, and improve patient outcomes when used together. In this study, it was planned to develop the aggression management care package in phase 1, and evaluate the clinical use of the aggression management care bundle in phase 2. The aggression management care bundle was developed following the guidelines of The Institute for Healthcare Improvement.

Inclusion Criteria:

• Being between 18-65 years of age,
• Being able to speak and understand Turkish,
• Having one of the disorders within the scope of Schizophrenia and psychosis,
• Being newly admitted to Bolu İzzet Baysal Mental Health and Diseases Hospital during the period the research was conducted,
• Having scored 1 point or more on the Broset Violence Checklist or 65 points or more on the Buss-Perry Aggression Questionnaire.

Exclusion Criteria:

• Not being able to give written informed consent,
• Being the first time a patient has been admitted to a psychiatric clinic,
• Having developmental delay or any other significant organic brain pathology.

Gender assignment is made according to gender identity. In the hospital, admissions to the psychiatry clinic are made to separate clinics according to the gender of the patient. There are no mixed clinics. Clinic names are male 1, male 2, female 1, female 2, etc.

Sharing data of psychiatric patients may pose some ethical and legal problems.

Patients and nurses do not know which group they are in, or which experimental or control groups they are in. The first tests were taken after patient consent to ensure blinding, but without assignment to groups.