The interface of physical and mental health – how categorical is it?

 The interface of physical and mental health – how categorical is it?

While common diagnostic algorithms often attempt to classify illnesses into organic and psychological entities, deeper inquiry makes a compelling case to rethink this dichotomous way of looking at disease. To begin with, organic diseases oft lead to psychological ones – for instance, hyperthyroidism is associated with anxiety, and diabetes mellitus with depression. The reverse is also true, for example, impulse disorders are associated with trichobezoars, and obsessive-compulsive disorders with dermatitis secondary to handwashing. Bodily neglect, as in schizophrenia leads to diabetes and cardiovascular disease, amongst others. Compounding this is the diagnostic bias – patients with illnesses such as schizophrenia are underdiagnosed for physical illnesses or diagnosed late, worsening prognoses. Another area of interface is that of disease manifestation – the porphyrias, for instance, are classified as haematological diseases, but can often present themselves with signs typical of psychiatric illness. Conversely, postural hypotension is wrought by therapeutic doses of anti-depressants and anti-psychotics. Considering this interconnected nature of diseases and their presentation, it prime, logistically and ethically, to move towards holistic evaluation and management of illnesses. Problem statements and diagnostic algorithms must therefore, consider psychiatric diagnoses along with medical and surgical ones, evaluating the patient in a wholesome manner.

 

Extending this line of thought, the stressor model of disease considers disease to be exacerbated by certain extrinsic and intrinsic stressors; interesting is that many stressors are psychological. Skin diseases such as psoriasis are set off by anxiety; allaying anxiety is thus a preventive method against dermatoses. Further, alcohol abuse and psychiatric conditions re-enforce each other, and bouts of alcohol intake can lead to somatic disease worsening. Acute pancreatitis, acute gastritis and variceal haemorrhage are all triggered by sudden alcohol binges. On the other hand, acute infections can also trigger several diseases, acute pancreatitis included. Here, the difference between a psychological stressor and a physical stressor is mostly semantical, for they both operate in a similar way; concern must thus be accorded in an equal fashion – allowing for better risk stratification and preventive programmes. 

Yet, the most pertinent argument concerns the pathogenesis of disease. The basis for classifying diseases into somatic and psychological ones was the lack of demonstrable signs in the latter. With modern investigations, it is well proven that psychiatric diseases are marked by clear radiological changes. Structural changes in the cortex have been demonstrated in several psychiatric conditions, reduced hippocampal volume in schizophrenia to name one. With the loss of the original basis, it should follow naturally that this demarcation is reserved for history. 

Studying Parkinsonism, we can conclude that much of the symptomatology – bradykinesia, resting tremors and rigidity - is to do with the loss of the dopaminergic drive. Depression, which is associated with Parkinsonism, also results from the lack of the said drive. (1) The case is for these two manifestations of the same disease, to be classed alongside one another. As discussed by Won et al (1), depression associated with Parkinson’s disease responds significantly to Monoamine Oxidase B – Inhibitors, in comparison to Selective Serotonin Reuptake Inhibitors. A reiterating study is that of pseudo-bulbar palsy (2) - disparate clinical entities such as metabolic diseases, vascular lesions, neoplasia and trauma lead to damage to the corticobulbar tracts, initiating an upper motor neuron lesion. This clinical syndrome is marked by dysphagia, dysarthria, dysphonia and trismus. Associated with this constellation of signs is emotional lability with pathological laughter, or crying with paradoxical poverty of expression, together termed the pseudo-bulbar affect. Here too, the pathogenesis is intricately linked; the onset is concurrent as well – therefore, for all practical purposes, the psychiatric and organic components of the disease, are well-knit. Finally, systemic lesions such as syphilis, lead to both psychiatric and neurological signs – affect disturbances and the Argyll Robertson Pupil. Hence, simultaneous consideration and diagnosis is an efficient way to provide comprehensive care to the patient. 

Thus, from the angles of risk factoring and stratification, preventive health, exacerbation and pathogenesis, psychiatric diseases and somatic diseases are closely intertwined. So much so, that the only answer to the rhetorical question the title poses, is that difference between these two categories is purely administrative, and that the only path forward, is to move towards integration.

References

1. Smith J, Petrovic P, Rose M, De Souz C, Muller L, Nowak B, et al. Placeholder Text: A Study. Citation Styles. 2021 Jul 15;3. 

2. Saleem F, Munakomi S. Pseudobulbar Palsy. [Updated 2023 Feb 12]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK553160/?report=classic