Hi, I am not sure what and how much you know about psychology. I think that it is important to make it clear that Psychology is more of a social science than a science. Why do I think that this is an important point to make? Everything you will read subsequently about diagnostic criteria and formulation hinges upon your understanding that Psychology is a SOCIAL SCIENCE. It is not an exact science.
Let me illustrate this...
In mathematics, we learn that 1 + 1 = 2. And, 1 - 1 = 0.
We also learn that 1 x 1 = 1. Plus, 1 / 1 = 1.
In order to solve more complicated mathematical questions, we need to first learn the numerical value of each number. Next, we need to learn the mathematical function of addition, subtraction, multiplication and division. The reason why 1 x 1 = 1 and 1 / 1 = 1 lies in the mathematical function of multiplication and division. We cannot change these functions or values. We may change the symbols we use, however, if we know what the values mean and how the function works, we can all universally arrive at the same answer.
When it comes to physical science like chemistry, we know that 2H2 + O2 --> 2H20. We cannot change this fact. We also know that in physics, Force = mass x acceleration. Again, we cannot change this fact.
However, in psychology, why is it that in a family of three biological siblings, one sibling suffers from anxiety and the other two siblings do not? They may share the same DNA but their psychological makeup and personal experiences are different. Why is it that two people were involved in the same car accident, yet one suffers from Post-Traumatic Stress Disorder while the other one does not? We don't know why. We may be able to explain this as resiliency or other reasons. We can also use the Stress-Diathesis or BioPsychoSocial aetiological models to explain why one individual suffers from a mental illness and why another individual does not. However, can we know for certain? Not at all. But based on the available research, mental health professionals can definitely make an educated guess.
Thank you for reading.
