Looking for Longitudinal study(s) of “anxiety/depression-related” symptoms

Does anyone know if there have been any studies following the long term outcomes of people who exhibit what I would term physical signs and symptoms (diarrhoea, tremors and shaking, irritable bowel, chills, aphasia, ataxia... etc - see places like webmd for lists) which have been widely ascribed to anxiety or depressive conditions?

Do we know what sort of percentages of such people (compared to normal controls) subsequently develop recognised physiological illnesses? Or don’t? Rates of morbidity and mortality?

I’m thinking about the direction of causality and the correlations made (is anxiety a symptom of a broad range of illness? Is this cluster of symptoms actually describing a pathology (anxiety/depression etc) or is it just a cluster of symptoms that can turn out to be a variety of ailments?)

Have any long term studies been done following people with such (undiagnosed or psychologically diagnosed) signs & symptoms?