Online marketing has become an important driver of consumer traffic to prescription drug Web sites, results from a recent study indicate.

According to the findings of an analysis conducted in October by Internet behavior tracking firm comScore Pharmaceutical Solutions, approximately 31% of visitors first become aware of pharmaceutical Web sites or products through an online program.

One-fifth of all consumer online researchers reported they first became aware of a product via an online search, with individuals age 35-54 accounting for 23% of those visits.

Other online marketing programs such as banner ads were responsible for driving 10% of all traffic, the study found.

Depression was the top-ranked therapeutic area with 2.9 million visitors, the survey said. Bipolar disorder and insomnia ranked second and third with 1.8 million and 1.7 million unique visitors, respectively.

“Key players in depression, bipolar and insomnia have invested heavily in the online channel, through banner and search campaigns,” said Carolina Petrini, VP of comScore Pharmaceutical Solutions.

“Pharmaceutical companies are increasingly realizing the impact of online marketing on patients and prospects and are re-allocating their marketing funds accordingly.”