Here are some useful links to not-for-profit organisations working to improve mental health in our society:

The Black Dog Institute
The Black Dog Institute provides information on diagnosis, treatment and prevention of mood disorders, such as depression and bipolar disorder.

Beyond Blue
Beyond Blue supports people of all ages, providing information regarding anxiety, depression, and much more.

Lifeline provides people experiencing a personal crisis with access to online, phone and face-to-face crisis support and suicide prevention services.  If you are at risk, call Lifeline now on 13 11 14.