"But partly it was my own professional background, my trainin..." — Lori Schiller quote meaning

But partly it was my own professional background, my training in psychology, that rather than helping me—made it almost impossible for me to face what was happening. Back when I studied psychology in the 1950s, there was only one cause for all mental illnesses, even the most severe: a faulty upbringing. Everything was tied to the way you were raised. There were different schools of thought, of course. Some practitioners followed a Freudian model where understanding the id, the ego and the superego gave the answer to everything. Some followed Jung, with his emphasis on unconscious myths. But everyone believed that it was early life experiences that were behind mental disorders. A patient with serious mental problems had been subject at an early age to unacceptable pressures, to confusing messages, or to some destructive behavior on the part of the parents.