Most prescription medications come with such a long list of potential side-effects that many patients may have no idea what they are getting themselves into.

But when the potential consequences include depression and suicide, ignorance is decidedly not bliss.

A new study has found that between 2005 and 2014, 37.2 percent of US adults may have been unknowingly using common medications that can cause depression as a side-effect.

"Many may be surprised to learn that their medications, despite having nothing to do with mood or anxiety or any other condition normally associated with depression, can increase their risk of experiencing depressive symptoms, and may lead to a depression diagnosis," said lead author Dima Qato, an assistant professor at the University of Illinois.

The National Health and Nutrition Examination Survey examined more than 26,000 Americans over the age of 18, excluding those who already use antidepressants.

The findings revealed that more than 200 commonly used prescription drugs list depression or even suicide as potential consequences. These popular medications include drugs like hormonal birth control medication, blood pressure medication, antacids and painkillers.

Many of these medications are available over the counter and their warning labels do not list comprehensive information on their potential adverse effects.

As a result, the researchers state that "many patients may therefore not be aware of the greater likelihood of concurrent depression associated with these commonly used medications."

To make matters worse, when these drugs are used together (called polypharmacy), they can exacerbate the prevalence of depression.

The survey found about 15 percent of the people who used three or more of these drugs experienced depression - a big jump from the 7 percent that used only one medication, and the 9 percent that used two medications. 

In comparison, only 5 percent of those surveyed experienced depression without taking any drugs, roughly three times fewer than those taking three medications.

The same sort of pattern was observed for medications that can cause suicidal ideations.

"The take away message of this study is that polypharmacy can lead to depressive symptoms and that patients and health care providers need to be aware of the risk of depression that comes with all kinds of common prescription drugs - many of which are also available over the counter," said Qato.

The need for awareness on this issue is vital, especially as polypharmacy becomes more popular. The study found that between 2005 and 2015, American patients taking more than one of these drugs jumped from 7 to 10 percent.

Nevertheless, a worrying number of patients and medical professionals have no idea about the risks that polypharmacy holds. Right now, typical depression screening tests do not take into account prescription medications that list depression as a possible side effect.

"People are not only increasingly using these medicines alone, but are increasingly using them simultaneously, yet very few of these drugs have warning labels, so until we have public or system-level solutions, it is left up to patients and health care professionals to be aware of the risks," Qato said.

The issue is even more pressing given that depression and suicidal side-effects are showing up more and more in pharmaceuticals.

The study found that depression side-effects increased by 35 percent in prescription medications between 2005 to 2006. From 2013 to 2014, that number went up to 38 percent.

When it comes to prescription drugs listing suicide as a side-effect, the numbers are even more worrisome, jumping from 17 to 24 percent over the same period.

At the same time, it is becoming more common to use multitudes of these drugs. The study found that the use of three or more drugs with suicidal side-effects has increased from two to three percent.

The new study comes shortly after a recent report by the Centers for Disease Control (CDC) that found a shocking rise in suicide rates across the US.

While it can't be said that this is directly related to the side-effects of prescription medication, it certainly speaks to a larger issue - namely, how much more the public health system needs to focus on depression and suicide.

Qato argues that in order to solve the problem identified in his study, we need to update our drug safety software so that patients, medical professionals and pharmacists are all fully aware that taking multiple medications may increase a patient's risk of developing depression or suicide.

"With depression as one of the leading causes of disability and increasing national suicide rates, we need to think innovatively about depression as a public health issue," Qato said.

"This study provides evidence that patterns of medication use should be considered in strategies that seek to eliminate, reduce or minimise the impact of depression in our daily lives."

The results have been published in Journal of the American Medical Association.

If this story has raised concerns or you need to talk to someone, here's a list where you may be able to find a crisis hotline in your country.