It has long been known that the more severe a mental disorder is, the greater the variety of symptoms it will manifest. A news study based on longitudinal data shows that virtually all psychological disorders shift throughout life, rarely maintaining the same diagnosis.
“Better than any particular diagnosis, three parameters described each person’s mental health over their life: (a) age of onset, (b) duration of symptom history, and (c) number of different kinds of comorbid disorder symptoms. People with younger onset of symptoms, more years with symptoms, and more different kinds of symptoms tended to be the same people. These people also had more indicators of poor brain health at age 3, steeper child-to-adult cognitive decline, and older brain-age on structural MRI at midlife,” Caspi explained.
“This finding cautions against over-reliance on etiological theories, research hypotheses, and clinical protocols that are specific to one diagnosis. Studying disorders one at a time does not accurately represent most patients’ lived experience of shifting across disorder families.”
“Studying one disorder may mislead about specificity and hide transdiagnostic discoveries from view. There is a need for measurement instruments that capture shared liability to shifting disorders across the life course in order to make discoveries more efficiently. There is also a need to develop transdiagnostic treatments that can prevent many different conditions,” Caspi said. (New psychology study finds people typically experience shifting mental disorders over their lifespan)
IMO, if we base our understanding of human psychology—including disordered psychology—on signals, the problem of wavering diagnoses becomes clearer.
A complex signal system once disordered cannot be expected to a maintain homeostasis of “disorderedness.”