In the country that I am from, to become a Psychiatrist, you first become a medical Doctor. Then you study medicine and its effects on the brain. Along with Psychology. So, in other words, just as a regular Doctor goes on to become a specialist, so does the Psychiatrist follow the same path.
Having a major in Psychology, I realized that as a subject, it is one of the most complex sciences. Two years is spent learning statistics, that is, measurable data equaling qualitative and quantitative results. The interplay of society, man in context, both in the macrocosm and microcosm of life is so important. As well as cultural influences. What is wrong in one culture may not be in another. In other words, a diagnosis is never made on a presenting symptom but more on the basis of a life-time of symptoms, or lack thereof, plus, stressors in the person’s life before and after the symptoms appeared. (Just to simplify). Often it can also be like any physical illness diagnosed on response to certain drugs.
Diagnoses are also made on many axes,(axis), where interplays of personality disorders influencing mental illnesses and vice versa.
So no, it is not a soft science, it is a rather complex one. However, like all sciences, it is constantly being updated.
The shit part is when you get NHS Psychiatrist handing out lithium for e.g. as a cure-all. Plus a tired and bored attitude to their job. Or even worse, a Psychologist that falls asleep while you are talking to her. (My experience). In that way, they are a bunch of quacks.
Scientology let’s not forget was invented by a fantasy writer and their biggest and highest branch is sea org. There is of course, no sea involved. I call Narcissism and psychopathic tendencies in David Miscavige.