See below. If you friend became concerned, then maybe s/he should. You might offer to go with your friend. The word of caution, any diagnosis is not made on the basis of a single test -- history, family history, behaviors, clinical interviews, observations and test will help with diagnostic picture.
Depends. There must of been a reason the test was taken in the first place. If there are concerns about depression, and the test results were significant for depression, the person should be seen.