New York, June 26 (IANS): A class of anti-depressants commonly prescribed to curb menopausal symptoms may boost bone fracture risk, warns a study.

The heightened risk associated with SSRIs (selective serotonin reuptake inhibitors) seems to last for several years, the results of the study showed.

"SSRIs appear to increase fracture risk among middle-aged women without psychiatric disorders -- an effect sustained over time -- suggesting that shorter duration of treatment may decrease (this)," said researcher Matthew Miller from Northeastern University in the US.

For the study, the researchers focussed on 137,031 women with no mental health issues and aged between 40 and 64 who started treatment with SSRIs between 1998 and 2010.

They were compared with more than 236,294 women of the same age prescribed H2 antagonists or proton pump inhibitors (PPIs), typically used to treat indigestion, over the same time-frame.

Analysis of the data showed that fracture rates were significantly higher among the women treated with SSRIs.

The fracture rate was 76 percent higher among those prescribed SSRIs one year after starting treatment, 73 percent higher after two years and 67 percent higher after five years than it was among those treated with indigestion drugs.

Anti-depressants may alter bone turnover, shifting the balance in favour of bone thinning rather than bone strengthening activities, the researchers suggested.

The study was published online in the journal Injury Prevention.