It if weren’t for psychology, those scientists wouldn’t know what they were trying to scientifically “fix.”
You are describing biochemistry which can have a psychologically measurable result. Even so, most of the drugs perform little better than placebos in the scientific studies.
I recently attended the American Psychiatric Association Conference in Philadelphia and spent the week updating on all the evidence based methods approved for treating PTSD and traumatic memories. Virtually all methods merely temporarily blocked memory retrieval and did not resolve the problem permanently. The best treatment, other than the long process of psychotherapy, was the virtual reality programs that facilitated retrieval and reframing of the traumatic memory.
Generally, pharmacology does not treat psychological causes, it merely blocks the symptoms.