First off let me state clearly, all the theories (paradigms) are important and useful. Different things have different meanings to different people. Some people's issues are purely chemical or otherwise physiological, while other people may have learned negative or harmful things as children, and many will require nutritional or chemical help as well as aid and opportunity to relearn things that harm ourselves. I feel that starting by verifying normal brain function we can quickly help anyone with a physiological issue and move forward with other therapies for those that do not or have some + other psychological issues, So the first place to start should be blood tests to see what is and is not working as directed. This model is useful for many (if not all) proper diagnoses to be given, in my case, there is an issue with serotonin reuptake (increasing my feelings of depression), as well as a failure to turn iron into methylfolate. These two issues do not encompass my issues but they do exacerbate them, so starting here was wise and in my opinion a required first step for therapy to begin.
The Sociocultural Model is a fundamental part of any true healing, we all had formative experiences that could have, let us just say, been better. We all want and even need to feel well regarded by our peers and social media has been playing havoc with teenagers and young adults for example. Within this paradigm, we have the Family-Social Perspective (I would say "at the root of this model we have the Family-Social Perspective") where we can look to and find the roots of the issues we can take self-responsibility for through our own guided (therapy) practice of C.B.T. Cognitive-Behavioural Therapy. These things easily combine to allow the individual the opportunity to not only change the way one reacts (unconsciously) to stimuli (both internal and external) but also to ferret out those formative experiences that helped to create the thought process that one wishes to correct (change from negative to neutral or positive). For me, raised by junkies, I learned neglect, self-reliance (because no one else will for me), and mistrust. To this day I can honestly say that I am not sure that I have ever experienced the feeling of love (and If I have I am sure it overwhelmed me and caused a breakdown). It makes me sad to think I am not capable of feeling all the same things as others are or that when I do my experience is different (ASD1, not just MDD, PTSD, and Cyclothymic) and it is the primary reason I am so excited about the various "psychedelic" research studies that are going on. My therapist agrees that a truly therapeutic dose of MDMA would be a positive experience and may lead to significant, long-term, positive results.
Now, have I actually answered the question poised? I think not. The question was in essence what theory (model/ paradigm), from our textbook, do I find useful in understanding abnormal behaviour? The answer is there is no single answer. We each are different even as we remained the same. Personally, and of course, I am terribly biased here but, I believe that nearly all human dysfunction can be found and (hopefully) sorted out by understanding either/ both the specific brain/chemical failure in the individual and by understanding how they processed their experiences while in development (age 0-25). Even people that have had "good home lives" may have learned incorrect things from otherwise neutral/ positive experiences. A child seeing their mother happily remarried might learn that women are disloyal (to daddy) instead of learning that life changes and happiness can always be found despite unhappy events. I would test for chemical issues, do psycho-therapy in conjunction with C.B.T., and where appropriate, suggest therapeutically administered psilocybin. I do not simply wish to understand the whys, I want to give people the tools and support they need to actually, truly, heal themselves.
References
Grosse, S. (2020, November 24). Children with PTSD: Teachers Can Make a Difference. ProQuest.com. Retrieved November 23, 2021, from https://www.proquest.com/docview/2456871553.