An increasing number of American adults are being prescribed two or more psychiatric medications, according to a study published Tuesday in the Archives of General Psychiatry.
While the safety of antipsychotic and antidepressants drugs has been debated in children, this is one of the first studies to look at trends over time of prescribing multiple psychiatric drugs to adults. The authors found that patients are commonly prescribed untested combinations of drugs, where the efficacy and possible side effects of the combos are unknown.
The researchers from the department of psychiatry at Johns Hopkins University and New York State Psychiatric Institute studied prescription patterns beginning in 1996. They looked at a whole range of psychiatric medicines, from antidepressants such as Wellbutrin, to antipsychotic like Loxapac, as well as mood stabilizers and sedatives. From 1996 to 1997, 42 percent of patients were prescribed of two or more of these medications.
But for 2005-2006, that number had jumped to 60 percent. In the same 11-year time period, visits resulting in three or more prescriptions went from 17 percent to 33 percent.
The study looked at more than 13,000 visits to office-based psychiatrists from 1996 to 2006 using annual data from a national survey.
"There is growing evidence regarding the increased adverse effects associated with such combinations," the authors write. For example, they cite studies that have found some combinations have resulted in weight gain and increased cholesterol levels.
Certain combo prescriptions have been proven effective for specific illnesses, but patients in the survey were routinely given unstudied combinations.
Patients with major depression, bipolar disorder, anxiety disorders or schizophrenia were more likely to be prescribed combos of two or more psychiatric drugs. Similarly, patients with more than one diagnosis were more likely to be on multiple meds than those with only one diagnosis.
The study did not find an increase in the number of people with severe mental illness. Rather, the researchers say the increase in combo drugs is more likely to do with changes in how psychiatry is practiced.
"Some psychiatrists may be placing greater emphasis on symptom reduction while lowering their concerns over the number of medications required to achieve this clinical goal," the authors write.
The New York Times earlier reported on a study that found children covered by Medicaid are given powerful antipsychotic medicines at a rate four times higher than children whose parents have private insurance. While the study published this week didn't explicitly measure income, it did find that psychiatric drug combinations were more commonly prescribed to those covered by public insurance, such as Medicare.