Online tests for depression any good?

Yes as screen: Yes as a screen. While identifying symptoms of depression, it doesn't tell you the cause. Treatments may vary based upon possible causes. If the screen is possitive or your symptoms negatively impact your life see a professional to help diagnose.

Not the best: At best, online tests for depression are only useful for screening depressive symptoms...And that is if you happen to stumble across a well researched one. The best way to determine if you have depression is to visit with a psychologist or psychiatrist since there are different types of depression, which have different causes, and require different treatments.