London, Aug 14 (IANS): Regular intake of benzodiazepines, widely used to treat insomnia and anxiety, may be associated with an increased risk of Alzheimer's disease, a study has warned.

Even though the increased risk for Alzheimer's disease was small in this study, the threshold for prescribing benzodiazepines and related drugs should be high enough due to their several adverse effects and events, such as falls, said researchers from the University of Eastern Finland.

These medications are commonly used for sleep problems, but their effectiveness for this indication diminishes over weeks or months. However, the risk of adverse events remains in longer-term use.

The results, published in Acta Psychiatrica Scandinavica, showed that the risk increase was similar with both benzodiazepines and Z drugs regardless of their half-life.

The study included all Finnish community dwellers with newly diagnosed Alzheimer's disease in 70,719 persons, and their age, sex and region of residence matched controls (282,862 persons).

Many chronic disorders, substance abuse, socioeconomical position and use of antidepressants and antipsychotics were taken into account. To account for reverse causality, drug use within 5 years before Alzheimer's disease diagnosis was not taken into account.

After adjustment for other psychotropics, it is possible that the association may partially be due to antidepressants and/or antipsychotics, or concomitant use of these medications, the researchers noted.