Morgan DJR, et al. - Using data from Western Australian Department of Health Data Linkage Branch records, researchers conducted this statewide, mirror-image, longitudinal cohort study to explore the relationship of bariatric surgery with the incidence of outpatient, emergency department, and inpatient mental health service use. Data of a total of 24,766 patients [mean age: 42.5 (11.7) years; 19,144 (77.3%): women] who underwent index bariatric surgery were obtained. One in six patients undergoing bariatric surgery used at least one perioperative episode of a mental health service over a 10-year study period. Significantly more common outpatient, emergency department, and inpatient psychiatric presentations were observed after surgery compared with before surgery. This was especially noted among those who had prior psychiatric illnesses or had surgical complications that needed further surgery. Such results indicate either inefficacy of or inconsistent adherence to the current professional bariatric surgery guidelines recommending preoperative psychological assessments and the deferment of surgery in patients with active psychiatric conditions. It is recommended that patients be regularly assessed and advised about the possible associations of bariatric surgery with mental health outcomes.