Diagnosing a psychiatric disorder, it goes without saying; is a rather complex procedural matter. All or most psychiatric disorders conway patients as they are being referred will all have their own unique set of complexities, let it be said. At the same time, there is no reason why residents cannot refer themselves for treatment. Indeed, a clinical or medical prescription is not required for psychiatric treatment in general.
Of course, how are you to know that you need psychiatric treatment in the first instance? And so it goes too that in many cases, specialist or presiding psychiatrists may have protocols in place which means that they will only act on the presumptions made by their medical colleagues. Nevertheless, diagnosing an acute condition does take time. Of course, there will be those cases where a prognosis could be drawn up within days.
It is all good and well to say that you have depression. You say this because you have been feeling sad, frustrated or unhappy for longer than you can remember. But in essence, who are you to say? Not even your general practitioner is in a position to provide such a statement. Usually, what happens is this. He should already have general familiarity with the symptoms of depression in whichever form.
And when he does detect positive signs of depression, he could go no further than providing the patient with something of a mild anti-depressant until such time that the patient is able to see the psychiatrist as the general practitioner will surely recommend. For the more extreme cases, it is only the psychiatrist who can prescribe the full treatment if you will. And it is only the psychiatrist who can make that formal announcement that, yes. you have depression. Or not.