Thank you for giving so much thought to my analogy. I don't want to overly belabor it, but I have some thoughts in response to your post.

My late boyfriend was a very good dancer. Twelve years after we became a couple, he had a stroke. Though it put him in a wheelchair for a while, he did recover his ability to walk. His gait was altered, giving him a slight limp, but he could walk a half mile at a reasonable pace. However, he never danced again. This was a clear case of damage to the brain disrupting his ability to do something that he had previously mastered. His left side was permanently weakened and harder to control. He received excellent physical therapy, which he worked hard at. Despite months of that, there was a limit to what ability he could recover.

I have no neurological impairment affecting my mobility. As evidence of that, I happen to be a good swimmer. However, I'm not much of a dancer. There is no physiologic impairment causing that. As a teen, I was shy, didn't socialize a lot, and rarely went to dances. My lack of dancing ability was due to lack of experience. I took some dance lessons and found that dancing can be learned. I improved, but didn't stick with the classes long enough to get good at it. There is nothing a physician could have prescribed to make me learn faster. You either put in the work it takes to master a skill, or you remain unskilled.

Undoubtedly, there is a neurological component to aptitude. Some kids have superior hand-eye coordination. These kids may shine on the baseball diamond. Some kids are never going to excel at pitching a baseball, no matter how much great coaching they receive and despite a willingness to practice hard. It doesn't mean that there is something physically wrong with them that might be corrected through a medical intervention.

I happen to believe that a lot of mental distress comes from a deficit in the skills of living, especially social/interpersonal skills. It takes an awful lot of the right experiences to produce an emotionally well-adjusted, competent human being. I'm amazed that so many people turn out as well as they do. Given a serious deficit in the needed experience, a person is going to find themself floundering in life. No amount of psychtropic medication is going to remedy that. The problem is not in the wiring or chemistry of the brain. The problem is in the mind. (I do recognize that a dearth of healthy experience growing up can impact the physiological development of the brain. But, even in that case, I think it's illogical to expect that drugs can really address the problem.)

I'm not against psychotropic drugs. Taking an antidepressant changed my life. It did not imbue me with the important skills I failed to develop in childhood. (Poor performance on the dance floor was not the only symptom of that.) Nor did going for psychotherapy prove particularly helpful. There is no complicated skill that can be learned from sitting with a "life coach" for one hour weekly. What's needed is immersion in activity that brings about learning, but is not so difficult that it totally frustrates. I like to think I've acquired some of that learning. Still, once you fall seriously behind your peers in some aspect of development, it's quite likely that you'll never fully catch up. I'm mainly talking about emotional development, and I'm mainly thinking of social skills, because I believe that interpersonal difficulty drives most psychological distress.

I don't wish to derail the thread. My point is that thinking of psychological difficulty as a "disease" of the brain can be very unprofitable. It fails to lead us to addressing the root problem. Plus, it impels us in a fruitless direction, seeking a medical remedy for what is not essentially a medical problem. I agree with the OP that a psychological problem can be chronic and can worsen over time and can even impair a person's ability to survive. That doesn't make it a physiologic disease like cancer, even though it may partly manifest in some observable physical symptoms. I also agree with you, TCJ, that we are sorely in need of some better expertise in just what can be done to address the distress of having emotional problems. However, if you're waiting for the science of neurology to produce that expertise, I think you wait in vain.