The finding:
The study found among individuals with CKD and MDD, elevated plasma hsCRP (high‐sensitivity C‐reactive protein) independently predicted response to sertraline but not to placebo. They retrospectively looked at the Chronic Kidney Disease Antidepressant Sertraline Trial (CAST) which had previously shown that treatment with sertraline vs placebo did not improve depressive symptoms in MDD patients with CKD not requiring kidney replacement therapy.  However, baseline inflammatory biomarkers (plasma hsCRP, albumin and pre-albumin) predicted a differential response. There were 193 participants who were assigned to either sertraline or placebo for 12 weeks and QIDS-C16 scale was used to quantify depressive symptoms.

Strength and weaknesses: 

Strengths:
Baseline characteristics were balanced between treatment groups.

Weaknesses:
Power was limited by few participants achieving remission. They did not measure biomarkers IL-1β or TNF-α which have been reported to be associated with depression in patients without CKD. Findings due to chance related to multiple comparisons cannot be ruled out.

Relevance:
Depression is common in CKD patients and is associated with poor outcomes including dialysis initiation, hospitalization, and death. In vitro and human research has suggested that sertraline may have anti-inflammatory effects which could explain improvement of depression in CKD patients. The study authors recommend addition of clinically useful cutoffs of inflammatory biomarkers which may improve prediction of sertraline response. This could have important implications for the CL psychiatrist as elevated hsCRP, low albumin and pre-albumin may be useful for identifying individuals more likely to benefit from sertraline. However, these findings need to be validated in future studies before becoming widely used as there is also evidence that high CRP predicts poorer response to SSRI’s in non-CKD depressed patients (CO-MED and GENDEP trial).

Type of study:
Retrospective cohort study

The Findings:
Given that depression is common in patients on haemodialysis (HD), up to one-third of patients, this cohort study evaluated antidepressant management in 41 patients on HD. Despite taking antidepressants, two-thirds of HD patients on antidepressants after a mean follow-up time of 14 months continued to endorse depressive symptoms. These patients also had minimal dose adjustments during the follow-up period despite ongoing symptoms. In addition to under-dosing, there was also 15% of patients prescribed antidepressants who did not meet criteria for major depressive disorder, indicating an issue of over-prescribing. Patients treated with antidepressants were most often prescribed citalopram, which has an increased risk of QT prolongation and sudden death in HD patients, also suggestion suboptimal management.  

Strengths:
This study was able to gather appropriate and useful baseline data, including the Beck Depression Inventory, as well as the Patient Health Questionnaire-9. On follow-up, a diagnostic interview including the Mini-International neuropsychiatric Interview (MINI) was performed as well as antidepressant adherence evaluation.

Weaknesses:
The cohort study included an overall small sample size of 41 HD patients on antidepressant treatment. Although different prescribers had started the antidepressant, including primary care providers, nephrologists, and psychiatrists, there were no comparison between patients in these three groups.

Relevance to consult liaison psychiatrist:
As a consult-liaison psychiatrist, we are often consulted on HD patients with concurrent depression. Although this study has a small sample, it does suggest that importance of further investigation into the prescription practices of antidepressants and management of depression in HD patients.

Type of study:
Cohort study