Design: This parallel randomized controlled trial (RCT) was conducted according to the Consolidated Standards of Reporting Trials (CONSORT).

Methods: In total, 90 patients were randomly assigned to either the intervention or the control group. After a 2-week washout period, the intervention group was reassigned to the control and vice versa. The CONSORT checklist for RCT was reported. Psychotic symptoms, emotional reactions, behavioral relaxation responses and heart rates were assessed at 6 time points.

This was a prospective randomized controlled trial with parallel groups following the Consolidated Standards of Reporting Trials and was approved by the Institutional Review Board of Jianan Mental Health Hospital (approval number Taiwan Nurses Association-1012023/ 12-002). Informed consent was obtained from all the subjects. Patients who had been hospitalized for schizophrenia, schizophreniform disorder, and schizoaffective disorder for more than 5 years according to Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (American Psychiatric Association, 2013) criteria were eligible to participate in the study. Patients who had a history of alcohol and drug abuse or could not concentrate on activities for at least 30 minutes were excluded from the study. As shown in the CONSORT diagram (Schulz et al., 2010), 109 patients were screened, 95 participants were enrolled by a research assistant and received interventions delivered by a nurse researcher. In the end, total 90 participants completely received multi-sensory stimulation therapy in a psychiatry institution in Southern Taiwan. None of the adverse events occurred. All patients were initially randomly assigned to either intervention or treatment as usual (TAU) group using a computer-generated random allocation sequence. The intervention group received six 30-minute MST sessions. During MST session, participants can choose their preferred sensory stimuli such as essential oil diffusers, music…etc.. The TAU group received usual routine care. After receiving either intervention or routine care, there was a 2-week washout period to clear the residual effects from the initial assigned group activities. Patients were then crossover into the other group where the process started over. Symptoms were assessed at baseline (T0), after the 1st session (T1), the 3rd session (T2) and the 6th session (T3). No important changes to the methods or trial outcomes were made after trial commencement.

Sample Size Calculation:

Sample size was calculated based on showing between group outcome differences after receiving MST according to a previous study (Cheng et al., 2017) of 60 patients who underwent the same comprehensive protocol. To achieve statistical significance p< 0.05, each parallel group of our study required at least 30 patients.

All the outcome assessments were by original assigned groups. Descriptive analysis was conducted for analyzing demographics and outcomes in all time points. Repeated Measurement of Analysis of Variance (ANOVA) was used to examine the effectiveness of MST between experimental and control groups. Effect size was determined using partial η2 that reflects the percentage of the variance in outcome variables explained by the independent variables.

Inclusion Criteria:

• hospitalized patients
• diagnosed with schizophrenia, schizophreniform disorder, and schizoaffective disorder for more than 5 years according to Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (American Psychiatric Association, 2013).
• aged above 20 years old

Exclusion Criteria:

• had a history of alcohol and drug abuse
• could not concentrate on activities for at least 30 minutes.

Not shared with other research teams.