It has been pointed out that psychotropic drugs may increase the risk of developing constipation, but there are few high-quality studies on constipation involving patients taking psychotropic drugs. In the present study, we collected data from the medical records of 1696 patients admitted to the psychiatric emergency ward of Showa University Northern Yokohama Hospital to determine the rate of laxative use in the last prescription. These patients were divided into two groups: one with and the other without laxatives. We statistically examined differences in patient background and drug therapy. The clinical dosage ratio was defined as the ratio of the dose of each drug, with the upper limit on the package insert of each drug set to 1. The results of multivariate logistic regression analysis suggested that older age, female, higher number of hospitalizations, longer length of stay, and clinical dosage ratio of conventional antidepressants, newer antidepressants, mood stabilizers, and benzodiazepines were associated with laxative use. By individual drug category, doses of quetiapine, levomepromazine, venlafaxine, and mirtazapine may be associated with laxative use.
 Authors' abstract