Painkillers, tranquilizers, antidepressants, antipsychotics: These are four types of medications doctors are increasingly seeing combined for senior patients. All affect the delicate and essential central nervous system — that is, the brain and spinal cord — so taking them together is problematic, especially for seniors.

A cocktail of such strong drugs elevates the risk of falls, memory problems, confusion and dangerous driving incidents, challenges that already tend to impact seniors more than the rest of the population. The U.S. Food and Drug Administration recently issued what is known as a black-box warning, the strongest the entity attaches to a product before pulling it from shelves, about the dangers of combining opioid painkillers with other medications that work on the central nervous system.

And with good cause. Doctors were seeing combinations of such drugs twice as often in 2013 as they did in 2004, according to a study conducted by University of Michigan researchers.

Another alarming trend the scientists uncovered… many patients did not have an ailment for which such medications were intended, such as sleep problems, persistent pain or a mental health condition. This was true in 46 percent of visits involving a patient on multiple central nervous system-affecting drugs.

The findings are based on data from a national, nine-year survey of physicians. What they don’t show is how often seniors actually were taking all the medications.

The researchers said the study raises concerns about trends in prescribing so that the medications don’t wind up creating more problems than they fix.