A study has revealed that older adults who consume the most renowned type of anti-depressant drugs increase their risk of developing fragile bones..

Through tests conducted on a group of Canadians, added 50 and above, it was discovered that adults who take selective serotonin reuptake inhibitors had 4 percent less bone mineral density in their hip bones.

Millions of people take the anti-depressants commonly called SSRIs that include Eli Lilly’s Prozac.

The study included 137 people, who took the anti-depressants, also doubled their risk of suffering a bone fracture, compared to more roughly 5,000 participants not taking the drugs.

About one in 10 of those who took the anti-depressants fractured a bone over the 5-year study period — often from minor falls — said the researchers from McGill University in Montreal, writing in the journal Archives of Internal Medicine.

The doubling of the risk of bone fractures held true even after taking into account the mostly elderly subjects’ reduced bone mineral density and higher risk of sustaining falls.

McGill researcher Brent Richards mentioned, “Fracture rates remain elevated despite adjustment for these two risk factors, indicating that other pathways, such as impaired bone quality leading to reduced bone strength, may be of particular relevance.”

“It’s not just the quantity of bone but the quality of the bone,” senior study author David Goltzman said in a telephone interview.

While increasing serotonin in the brain peps-up the mood of depressed patients, altering the chemical’s reabsorption in the body also affects bone development, Goltzman said.

The drugs appear to adversely affect osteoblasts, cells that form bone, resulting in more brittle bones.

Osteoporosis, which is basically the abnormal weakening or softening of the bone, common in elderly people, and some women after the menopause affects over half of Americans aged 50 or older, and afflicts four times as many women as men.

“I think at this stage, patients going on (SSRIs) should be aware of this,” Goltzman said. “Individuals should know that because of this all the usual lifestyle factors — maintaining good physical activity, having a good diet containing calcium and Vitamin D, not smoking — are important.”

It would also be practical to have a bone mineral density test before going on an SSRI, especially if the patient has had a low-impact bone fracture, Goltzman added.

According to Goltzman, a study where participants, not just elderly patients, are randomly chosen to receive an SSRI or a dummy pill is needed to prove the link to brittle bones.

Other popular SSRI brands are Pfizer’s Zoloft and GlaxoSmithKline’s Paxil.