Can the rorschach test tell if a person is clinical depressed and how severe is? how accurate is this test for diagnosing mental illnesses?

The Rorschach Test: The Rorschach Test is an associative test, by which I mean that it attempts to provide insight into subconscious thoughts by looking for associations suggested by intentionally ambiguous images. As such, if you are feeling depressed you might see pictures which represented that depression in the images. It is only a small part of a psychiatric assessment, and is not, by itself, diagnostic.

Good Question: According to one source:"the Rorschach measure of depression does not correlate well with clinical measures of depression..."Others say it's the cat's meow. It's back and forth. highly subjective.They try to make it consistent but it just turns out to be one piece of the pie.To a good clinician,depression is diagnosed via a rather standard set of measures without the need for little pictures

Projective tests: are not very helpful in making a diagnosis of clinical disorders in isolation. A careful medical and psychiatric history is needed along with a good physical exam, neurological exam and mental status exam. The Rorshach is a tool. You need to do a good work up and that requires using all the tools necessary to get a longitudinal history and a complete picture of the current state of functioning.