The Temporal Relationship Between Severe Mental Illness Diagnosis and Chronic Physical Comorbidity

Physical and mental health are tightly connected. A variety of chronic physical diseases are more likely to affect people with a major mental disorder. In contrast, chronically ill individuals feel anxiety and depression more frequently than the general population. The increased frequency of chronic physical health problems among people with severe mental illnesses, such as schizophrenia, bipolar disorder, and other non-organic psychotic illness, has also been well established in the field of research.

The co-existence of mental and physical conditions can lead to a diminished quality of life, longer illness duration, worse health outcomes, and shortened life expectancy. Therefore, developing ways to reduce the incidence of co-existing conditions and support those already living with mental illnesses and chronic physical conditions is very important. Additionally, the 2019 Lancet Psychiatry Commission emphasized that interventions should focus on extending a person’s life span and giving them the capacity to live their life without limits. To achieve this, it is crucial to understand the temporal relationship between severe mental illness and physical health diagnoses, which a study under The Lancet Psychiatry focused on. This article will walk you through some of its important findings.

Introduction

The temporal link between the onset of a physical illness and the diagnosis of a serious mental illness is still unknown, despite the higher prevalence of physical health issues in those with schizophrenia, bipolar disorder, and other psychotic disorders. 

Understanding which physical diseases are more prevalent before a serious mental illness is diagnosed and which are more prevalent after a diagnosis since this knowledge will help determine when potential preventive or treatment strategies should be implemented. 

An example would be physical illnesses that appear before a diagnosis of severe mental illness, which may be an early symptom, lifestyle-related, or have causes in common with severe mental illness. However, preventive therapies for these illnesses cannot be provided unless they are provided at a community level or in a service dedicated to high-risk or patients with early signs.

Therefore, if appropriate early intervention services were built, knowing which physical diseases are more common at the stage of severe mental illness diagnosis could potentially allow for screening and intervention.

The Temporal Link Between Severe Mental Illness Diagnosis and Chronic Physical Comorbidity

The recent study under The Lancet Psychiatry aimed to contribute knowledge of the temporal association between severe mental illness diagnosis and chronic physical disorders to help develop appropriate interventions.

The researchers of the said study determined the combined occurrence of 24 chronic physical illnesses in patients with schizophrenia, bipolar disorder, and other psychotic illness from 5 years before to 5 years after their severe mental illness diagnosis.

They also analyzed the annual chances of being diagnosed with new physical conditions among people with severe mental illness compared with those without.

After a thorough examination of 68 789 people who received a diagnosis of severe mental illness between Jan 1, 2000, and Dec 31, 2018, the researchers arrived at the following crucial findings:

In terms of patient characteristics and the number of physical health conditions in people with severe mental illness:

• People with schizophrenia were more likely to be male and younger than those with bipolar disorder.
• Patients with severe mental illness were more likely to be obese or current smokers at the time of diagnosis.
• Patients with schizophrenia were more likely to be people of color or Asians, while those with bipolar disorder were more likely to be White.
• The most common chronic physical health conditions during the time of the first recorded severe mental illness diagnosis were asthma, hypertension, diabetes, neurological disease, and hypothyroidism. Patients are also likely to be diagnosed of least one of these physical conditions during this time.
• After 5 years of severe mental illness diagnosis, patients are more like to have at least 2 or more of the stated conditions above with increased chances of their occurrence.
• The biggest increases in occurrence from diagnosis and 5 years after diagnosis were in renal disease, fluid and electrolyte disorders, diabetes, hypothyroidism, and chronic obstructive pulmonary disease. 

In terms of frequency of co-existing physical and mental health conditions:

• Patients with schizophrenia have higher possibilities of five out of 24 physical health disorders at the time of diagnosis.
• Individuals with schizophrenia had elevated possibilities of 13 physical conditions 5 years after diagnosis.
• Common chronic conditions with increased odds after 5 years of diagnosis for people with schizophrenia include neurological disease, diabetes, liver disease, chronic obstructive pulmonary disease, and pulmonary circulation disorders.
• People with bipolar disorder have an increased chance of 15 of the 24 chronic conditions at the point of bipolar disorder diagnosis. 
• Chronic conditions with the most elevated odds among those diagnosed with bipolar disorder are hypothyroidism, neurological disease, fluid and electrolyte conditions, diabetes, and paralysis or paresis.

From the findings above, it can be concluded that people with severe mental illness are more likely to have several long-term physical health issues. These conditions vary according to the type of serious mental illness and the time since the diagnosis.

Key Takeaway

Increased probabilities of various illnesses at the time a diagnosis of serious mental illness is made lead to the conclusion that early intervention in physical health conditions is required to lower morbidity and early death. Given that many chronic physical conditions already exist at the time when severe mental illnesses are diagnosed, these conditions should not be seen as an unavoidable result of the side effects of medications for mental disorders and long-term health risk factors, such as poor diet, smoking, or alcohol and drug abuse. 

There is a need to think about immediate strategies for physical and mental health in this population because interventions meant to improve the physical health of persons with severe mental illness may have been started too late compared to the disease’s development.

Journal Reference

Launders, N., Kirsh, L., Osborn, D. P., & Hayes, J. F. (2022). The temporal relationship between severe mental illness diagnosis and chronic physical comorbidity: A UK primary care cohort study of disease burden over 10 years. The Lancet Psychiatry, 9(9), 725–735. https://doi.org/10.1016/s2215-0366(22)00225-5