Identifying unique subgroups in suicide risks among psychiatric outpatients

BACKGROUND

The presence of psychiatric disorders is widely recognized as one of the primary risk factors for suicide. A significant proportion of individuals receiving outpatient psychiatric treatment exhibit varying degrees of suicidal behaviors, which may range from mild suicidal ideations to overt suicide attempts. This study aims to elucidate the transdiagnostic symptom dimensions and associated suicidal features among psychiatric outpatients.

METHODS

The study enrolled patients who attended the psychiatry outpatient clinic at a tertiary hospital in South Korea (n = 1, 849, age range = 18-81; 61% women). A data-driven classification methodology was employed, incorporating a broad spectrum of clinical symptoms, to delineate distinctive subgroups among psychiatric outpatients exhibiting suicidality (n = 1189). A reference group of patients without suicidality (n = 660) was included for comparative purposes to ascertain cluster-specific sociodemographic, suicide-related, and psychiatric characteristics.

RESULTS

Psychiatric outpatients with suicidality (n = 1189) were subdivided into three distinctive clusters: the low-suicide risk cluster (Cluster 1), the high-suicide risk externalizing cluster (Cluster 2), and the high-suicide risk internalizing cluster (Cluster 3). Relative to the reference group (n = 660), each cluster exhibited distinct attributes pertaining to suicide-related characteristics and clinical symptoms, covering domains such as anxiety, externalizing and internalizing behaviors, and feelings of hopelessness. Cluster 1, identified as the low-suicide risk group, exhibited less frequent suicidal ideation, planning, and multiple attempts. In the high-suicide risk groups, Cluster 2 displayed pronounced externalizing symptoms, whereas Cluster 3 was primarily defined by internalizing and hopelessness symptoms. Bipolar disorders were most common in Cluster 2, while depressive disorders were predominant in Cluster 3.

DISCUSSION

Our findings suggest the possibility of differentiating psychiatric outpatients into distinct, clinically relevant subgroups predicated on their suicide risk. This research potentially paves the way for personalizing interventions and preventive strategies that address cluster-specific characteristics, thereby mitigating suicide-related mortality among psychiatric outpatients.

Chronic kidney disease incidences in Thai outpatients diagnosed with psychiatric illnesses receiving lithium maintenance therapy: a university hospital-based study

BACKGROUND

There has been no previous study in Thailand regarding the incidence of lithium-induced abnormal renal function. Hence, this study aimed to assess the effect of lithium maintenance therapy on chronic kidney disease, and associated factors among outpatients diagnosed with a psychiatric illness within Southern Thailand.

METHODS

This was a retrospective study, using an information review from the electronic medical records of Songklanagarind Hospital computer system in the last ten years; from 1 January 2013 until 31 September 2022. Chronic kidney disease was defined as an estimated glomerular filtration rate of less than 60 mL/min/1.73 m2 and persisted for three months or more. There were 461 outpatients diagnosed with a psychiatric illness who received lithium maintenance therapy. From this, 154 outpatients were excluded: 153 received lithium therapy for less than three months and 1 presented with a baseline chronic kidney disease. All data were analyzed using Rstudio 4.3.1. The incidence of lithium-induced chronic kidney disease was analyzed by survival analysis.

RESULTS

Of the 307 outpatients diagnosed with a psychiatric illness and received lithium maintenance therapy, the most common diagnosis was bipolar disorder (59.3%). Most were female (52.8%), with the median (IQR) age of 39.0 (27.5-54.0) years. The median (IQR) age onset of lithium therapy and duration of lithium maintenance therapy were 28.0 (21.0-41.5) years, and 2.97 (0.9-9.2) years, respectively. This study identified six outpatients (1.9%) that developed chronic kidney disease stage 3 or more and one of them (0.3%) presented with chronic kidney disease stage 5 or end-stage. The incidence of lithium-induced chronic kidney disease was 0.0023 cases per exposed patient-year. When comparing outpatients who had received lithium maintenance therapy and developed chronic kidney disease with those who did not develop chronic kidney disease, this study identified that most of the group with chronic kidney disease had a lithium maintenance therapy for more than ten years, had an older age onset of lithium therapy, reported history of psychiatric hospitalization and lithium intoxication, and presented with physical illness. The associated factors between the effect of lithium maintenance therapy and chronic kidney disease could not be identified due to a limited number of outpatients having developed chronic kidney disease.

CONCLUSIONS

Lithium-induced chronic kidney disease was identified as a minor incidence, and it was likely safe for maintenance therapy with careful and regular monitoring. However, older patients or those receiving lithium for a longer time and present with comorbid physical illnesses should be prescribed with caution.

IRB / IEC CERTIFICATION

65-389-3-4.