Mental illness in patients with chronic kidney disease

Chronic kidney disease (CKD) affects more than 10% of adults worldwide. Mental health is an important yet under-recognized issue in patients with CKD. Depression is common and related to poor prognosis in CKD patients, but previous research has primarily focused on dialysis patients, leading to an insufficient understanding of depression in earlier stages of CKD.

Antidepressants, the main pharmacological treatment for depression, are widely used in CKD patients, but there are uncertainties about the risks and benefits of antidepressants use and questions about whether drug dosage is appropriately adjusted based on patients' kidney function. There is also a lack of knowledge about less common but severe mental illnesses, such as bipolar disorder and schizophrenia in patients with CKD.

In his thesis from Karolinska Institutet, Nanbo Zhu, Ph.D. student at the Department of Medical Epidemiology and Biostatistics, addressed these knowledge gaps by investigating the prevalence and impact of mental illnesses, as well as examining the utilization and safety of antidepressants in patients with CKD.

Nanbo's thesis reveals the commonness and negative impact of mental illness in patients with CKD, pointing to the need for recognition and effective management; it provides real-world evidence regarding the prescribing and safety of antidepressants in the CKD population, offering insights for informed treatment decision-making.

What are the most important results in your thesis?

We found that depression, bipolar disorder, and schizophrenia were more common in patients with CKD than the general population. CKD patients with these psychiatric diagnoses faced adverse health outcomes and potential disparities in health care access. Among patients with CKD and depression, those who started treatment with antidepressants experienced a higher occurrence of short-term adverse events such as hip fracture and upper gastrointestinal bleeding, but not long-term mortality, cardiovascular, and kidney outcomes.

Importantly, selecting an appropriate type and dosage of antidepressants could improve treatment safety. In routine clinical practice, it seemed that prescribers did not adequately consider patients kidney function when prescribing antidepressants, resulting in suboptimal dose adjustments and potentially increasing the risk of adverse drug reactions.

Why did you become interested in this topic?

Mental health conditions are common but underrecognized and undertreated in patients with CKD, partly due to a lack of knowledge in this research area. Leveraging the data sources (e.g., Stockholm CREAtinine Measurements project) at our disposal and sophisticated methods, we hoped to advance the understanding of mental illnesses and their treatment in patients with CKD.

What do you think should be done in future research?

Future studies that incorporate a broader range of neuropsychiatric conditions are warranted to comprehensively assess their burden in patients with CKD. In addition, real-world benefits and risks of antidepressants in patients with CKD could be more thoroughly investigated by future research, including the exploration of heterogenous treatment effect.