The current project aims to evaluate the extent to which psychological interventions based on Cognitive Behavioral Therapy (CBT), provided within the framework of care, may be helpful for patients in psychiatric inpatient care. The background to the project is the substantial lack of psychological treatment available to patients in psychiatric inpatient care, despite evidence suggesting that active psychological interventions can have a positive effect on psychiatric problems, such as reduced depressive symptoms, decreased anxiety, and reduced rates of readmission to inpatient psychiatric care. Previous research evaluating the effects of CBT in inpatient settings is, however, rare and more knowledge is needed both nationally and internationally. In addition to the potential direct effect of psychological treatment on patients' difficulties, there is also a high demand for such support from patients, for example, as expressed at patient forums conducted by participation coordinators in Region Stockholm, Sweden. In psychiatric outpatient and primary care, there is currently good evidence supporting CBT, and these methods are highly beneficial for both patients and practitioners. Digitalization and blended formats, with therapist-supported internet treatments, can also increase access to interventions. Studies of CBT for, for example, depression, anxiety, and psychosis are well documented and have shown a significant reduction in psychiatric symptoms as well as improved quality of life. But scarcity of studies conducted in inpatient care limits available knowledge on feasibility and effects of CBT interventions to this group of patients. This strongly motivates further systematic evaluation and research on CBT in inpatient psychiatric care, and the aim of the present study is to implement and evaluate CBT in this context. Investigators plan to test this at four to six psychiatric inpatient units and evaluate the impact of the intervention on patients' levels of activity and symptoms of low mood and depression in a randomized controlled trial. In addition, investigators wish to conduct two different interview studies with patients and staff to obtain a detailed description of how they experience the intervention.

Access to psychological treatment and Cognitive Behavioral Therapy (CBT) is limited in Swedish psychiatric inpatient care, despite increased support for the usefulness and effects of CBT in outpatient care. Although more research is needed from inpatient contexts, initial studies shows that CBT can provide positive effects beyond medication, including reduced readmission rates and alleviated symptoms. This study aims to investigate whether CBT delivered by mental health professionals is feasible and beneficial for patients in inpatient care.

The project includes three separate studies and the present registration concerns study 1, a randomized controlled study to evaluate the effects of the intervention. Study 2 and 3 are qualitative studies exploring the experiences of the intervention from the perspectives of mental health professionals (study 2) and patients (study 3). The primary research questions in study 1 are:

1. Do participants who receive brief CBT during their inpatient care report significantly higher activity levels of behavioral activity, as measured by BADS-SF (Behavioral Activation Depression Scale - Short Form), compared to participants who receive treatment as usual?
2. Do participants who received brief CBT during their inpatient care period report significantly higher levels of perceived health, as measured by CORE-10 (Clinical Outcome in Routine Evaluation - 10), compared to participants who receive treatment as usual?

In total, 204 participants are recruited from four to six psychiatric inpatient units in Stockholm (Sweden) and at each individual unit, participants are randomized to one of two conditions: (1) CBT or (2) Treatment as usual. At the units where the study is conducted, a structured approach to offering conversations called Daily Conversations (DC) are a part of the usual inpatient care. The effects of the intervention/brief CBT are evaluated using psychometrically validated self-report questionnaires, which are collected during routine admission interviews and conducted by nursing staff on each ward. At admission, information about the study is provided and participants' consent is collected. This can also take place at a later time if the staff considers it appropriate. To increase the likelihood of obtaining participants self-reports at discharge and minimize attrition, investigators are also using digitalized questionnaires delivered via smartphone applications or computer. In addition, the patients rate patient satisfaction and experience of the treatment intervention prior to discharge from psychiatric care. Questionnaires have been chosen due to their psychometric properties and are widely used in research on patients with psychiatric problems/symptoms. To avoid burdening participants and staff with excessive administration, investigators have chosen instruments with few questions, and that are already used in inpatient care. In addition to self-report questionnaires, data from medical records of each participant are collected with written consent. This includes information on periods of care in psychiatric inpatient settings during the months prior to and following discharge, coercive measures during the care period, medication, and current diagnoses for each participant. These data are used to describe the sample of enrolled participants, and to facilitated assessment of external validity and generalizability of findings. Follow-up will be conducted at three months following discharge, and at one year following discharge.

Statistical analysis is performed using LMM (Linear Mixed Model) analysis of main effects of each condition, interaction effects of group and time (effect of the intervention). Descriptive analysis of demographic data is performed to characterize the sample.

Reporting of the results follows the recommendations provided by the CONSORT guidelines (Consolidated Standards for Reporting Trials). To meet the requirements for a higher scientific standard and increase transparency and quality, the study is pre-registered on ClinicalTrials.gov. To further facilitate external review, Rob2 (Risk-of-bias 2), Cochrane's tool for assessing risk of bias in randomized trials, is used.

The intervention is called "Brief CBT" and consists of psychological therapy sessions based on elements of Cognitive Behavioural Therapy (CBT), Acceptance and Commitment Therapy (ACT), and Behavioural Activation (BA). The treatment is manualized and focuses on training patients to engage in activities that are meaningful and enhance quality of life in both the short and long term. During the sessions, patients receive support in focusing on and articulating what they perceive as important and meaningful for themselves, and they are helped to manage distressing thoughts and feelings. The manual serves as a support and working material for staff and patients, providing structure for the sessions. It also allows the patient to read and learn more about the content at any time, which increases their participation and involvement in the treatment. The goal is for the intervention to be delivered daily, but if this is not possible, staff are encouraged to offer sessions every other or every third day. This is because the length of inpatient care periods in psychiatric wards is limited. A treatment session can be as short as 15 minutes but also up to an hour. The length is adjusted to how long the patient can actively participate. If the patient is hospitalized for a longer period, the number of sessions can be increased according to their wishes. This is particularly relevant for units with longer care periods, such as psychosis and geriatric psychiatry wards.

Training for staff consists of four half-days covering theory and practical exercises focused on key parts of the manual/intervention. The following areas are addressed:

• Basic knowledge of cognitive behavioral therapy.
• Focus on structure, working alliance/relationship, and intervention/change in sessions.
• Basic interventions regarding goals, values, and focus on meaningful activities.• Basic psychoeducation and interventions focused on behavioral activation and discovering the connection between activity and well-being.
• Individually tailored interventions for sleep difficulties, managing and regulating emotions, handling voices, problem-solving skills, breathing, and relaxation exercises.
• Managing termination and planning for maintenance after discharge.

After completion of the initial training, 12 biweekly group supervision are sessions held, given to each ward. This is to provide opportunities for active participation for everyone in the group and to enhance the conditions for learning. The duration for implementing the training and supervision for each unit is approximately six months.

Inclusion Criteria:

• Admitted as patient in Psychiatric Inpatient Care
• Expected to remain admitted on the ward for at least 3 days
• Assessed as being capable of giving consent regarding participation.
• Assessed as able to engage in and complete conversations.
• Sufficient level of language skills to understand the content of conversations and client material included in the intervention.

Exclusion Criteria:

• Other ongoing psychotherapeutic contact.

Individual participant data on all outcome variables will be shared via a repository at Karolinska Institutet, KI Data Repository (https://kib.ki.se/en/publish-analyse/publish-and-share-research-data/ki-data-repository). This includes data on primary as well as secondary outcomes.

The IPD and supporting information will be available when the manuscript will be submitted. The planned date for submitting the manuscript for this study is December 2028.