More consumers are utilizing the internet for researching prescription medication information, a new study finds, with depression remaining the leading condition researched online.

According to data released by research firm comScore Networks, 33 million Internet users visited a prescription medication site in the third quarter in 2006, an increase of 13 percent the same period a year ago. Of those, 2.9 million unique visitors researched depression.

Consumers are increasingly looking to the Internet to become more knowledgeable about medications that have been prescribed by their doctors, or that seem relevant for their symptoms, said Carolina Petrini, vice president of comScore Pharmaceutical Solutions.

Two-thirds of visitors to prescription medication sites reported conducting research for themselves, with 10 percent conducting research for a spouse and 6 percent for a child, the study finds.

Top searches for specific health conditions by the number of unique visitors were: depression, 2.9 million; bipolar disorder, 1.8 million; and insomnia, 1.7 million.

The results come from replies by 411 respondents to a pharmaceutical survey e-mail request.