For the first time, the charity will market a web site address rather than a phone number as a means of contact.
An integrated push, which launches today (Wednesday), will direct users to a specially developed site (www.changeourminds.com).
The site includes information about emotional health, a game to measure users' emotional quotient and the chance to download a free track from the latest Radiohead album.
An email is being sent to a database of 200,000 people to promote the site, while banner ads are being negotiated through Mindshare, the charity's media agency. All creative is through Agency Republic.
An email support service is also being launched; it will link through to the site and www.samaritans.org. It will be marketed through both schools and universities.
David Richards, director of marketing at Samaritans, said: "We are targeting 15- to 25-year-olds, who are the main audience for depression. Young people may find it easier to express their feelings by email."