Polypharmacy is prescribing more than one drug to the same patient for the same condition. It is recommended in some situations but in others drugs can work together to cause side effects and polypharmacy also adds to the costs of medical treatment. Researchers from Johns Hopkins University in Baltimore and Columbia University in New York analyzed 13,079 visits to psychiatrists in the U.S. between 1996 and 2006. They found that visits to the psychiatrist in which two or more drugs were prescribed rose from 42.6% in 1996/7 to 59.8% in 2005/6. Prescriptions for two or more antidepressants, antipsychotics, sedatives/hypnotics and antidepressant-antipsychotic combinations significantly increased across the period of the survey. The odds of prescribing two or more antidepressants were significantly associated with major depression, two or more antipsychotics were associated with schizophrenia, two or more mood stabilizers with bipolar disorder and two or more sedative/hypnotics with anxiety disorders.
Mojtabai, Ramin and Olfson, Mark - National trends in psychotropic medication polypharmacy in office-based psychiatry Archives of General Psychiatry January 2010, 67(1), 26-36