Purposeful sampling is chosen to capture both patient and healthcare provider perspectives on emergency departments. Additionally, using criterion-referenced sampling, the study would focus on the factors that influence patients with mental health problems to seek support from the emergency department and the responses of emergency department staff regarding patient care. Therefore, at the end of the study, information regarding the increasing rate of patients with mental health problems in the emergency department of a public hospital would be provided. For these reasons, interviewees would be selected from different educational and socioeconomic backgrounds, gender, age and mentality type