Yeah, the book explictly warns about that kind of thinking about causality and how it should properly be addressed:

> If you do notice a physical sign in one of your patients, whether it is old or new, you want to be sure that you fully understand its cause and significance. It is crucial to be sure that a competent physician has eval- uated the finding within a reasonable time frame, given the evolution of the sign. Also, you will want to talk with that physician or obtain the medical records of the evaluation. You are looking for answers to the following questions: What is the etiology of the physical finding? Do the physical sign and the psychological presentation have anything to do with one another? And if they are related, how are they related? Are they both being caused by one underlying disorder? Is one causing the other? Or are two somewhat independent processes interacting in a complex way?

> When trying to sort out this issue of causality, there is the danger of being drawn too quickly to one of two poles. At one pole lies the danger of assuming that the physical sign has nothing to do with the psycho- logical presentation. At the other pole is the danger of assuming that the psychological problem is the sole cause of the physical sign via a psychosomatic process, stress, a masked depression, the consequences of the person’s lifestyle, or something of that sort. All practitioners, including primary care physicians, specialists, and psychotherapists, are vulnerable to these errors, especially when they are dealing with a patient who has a history of psychiatric hospitalization or in some other way looks like a “mental patient.”

(p106)