Mental health is an under-addressed issue in people with chronic kidney disease (CKD). When it has been explored, research has focused on the prescription of antidepressants–most commonly selective serotonin reuptake inhibitors (SSRIs)–to treat depression in patients who were undergoing dialysis for kidney failure, yet despite this, appropriate doses of antidepressants at different levels of kidney function remain uncertain. Little is also known about either the mental health of people in earlier stages of the disease, or about how mental health issues other than depression may impact a CKD patient’s prognosis. 

Here’s what Nanbo Zhu, a Ph.D. student in Medical Epidemiology and Biostatistics at Karolinska Institutet, discovered about the prevalence and impact of mental illnesses on, and the safe use of antidepressants in, CKD patients.*

What he did

Zhu’s thesis involved four studies:

• Study 1 evaluated to what extent patients’ kidney function influenced SSRI dosing in routine practice. 
• Study 2 examined the relationship between a new depression diagnosis and adverse outcomes in CKD patients who were not on dialysis. 
• Study 3 explored the comparative safety of antidepressant treatment in patients with CKD and new cases of depression. 
• Study 4 examined the prevalence of depression, bipolar disorder, and schizophrenia in patients with CKD, along with their impact on clinical outcomes.

What he found

Zhu’s findings revealed that:

• Depression, bipolar disorder, and schizophrenia were 60% more common in people with CKD than in the general population.
• Each of these disorders was linked to a higher mortality rate. Bipolar disorder was noticeably linked to faster decline in kidney function. Despite this, CKD patients with bipolar disorder and/or schizophrenia were less likely to initiate kidney transplants, suggesting potential barriers to healthcare access.
• New depression diagnoses were significantly associated with:
  • Hospitalization
  • CKD progression
  • Major cardiovascular events
  • All-cause mortality (death due to any disease, complication, accident, or hazardous exposure).
• Lower eGFR (percentage of remaining kidney function) was associated with being prescribed SSRIs with a reduced initial or maintenance dose. Still, two-fifths of patients with very low eGFR received SSRI prescriptions without proper dose reduction. 
• CKD patients with depression, who started treatment with antidepressants, experienced more short-term adverse events (hip fracture, upper gastrointestinal bleeding), though not long-term ones such as all-cause mortality, cardiovascular and kidney-related events, or suicidal behavior, than those who did not start taking antidepressants.

What it means 

According to Zhu, the findings clearly point out the necessity of:

• Improved recognition and management of mental health issues in CKD patients,
• Selecting a type and dosage of antidepressant that is safe and effective relative to a patient’s kidney function, and
• More thorough research on the burden of a wider range of neuropsychiatric conditions on people living with CKD, and how they can best be treated.

*Karolinska Institutet. (2024, January 12). Mental illness in patients with chronic kidney disease. Medical Xpress. https://medicalxpress.com/news/2024-01-mental-illness-patients-chronic-kidney.html