APA Dictionary of Psychology

slow and shallow breathing that can be induced by opioids and other sedatives. These drugs raise the threshold level of respiratory centers in the medulla oblongata of the brain that normally would react to increased carbon dioxide in the tissues by increasing the rate and depth of breathing. Respiratory depression is a primary hazard of the use of morphine and other opioid analgesics, but it is also observed with CNS depressants, such as barbiturates. Respiratory depression is less common with benzodiazepines unless they are taken together with another CNS depressant, such as alcohol.