In many documented cases, dextromethorphan has produced psychological dependence in people who used it recreationally. It is considered less addictive than other common cough suppressants, such as the weak opiate codeine. Since dextromethorphan also acts as a serotonin reuptake inhibitor, users report that regular recreational use over a long period of time can cause withdrawal symptoms similar to those of antidepressant discontinuation syndrome. Additionally, disturbances have been reported in sleep, senses, movement, mood, and thinking.