Dados do Trabalho

Título

What is the temporality between poor quality of sleep and mental health status: a prospective cohort with dental students

Introdução

The literature demonstrates an association between quality of sleep and mental health in adults, but the temporality between these two conditions is not yet well established.

Objetivo

To investigate the possible bidirectional relationship between poor quality of sleep and self-reported mental health status.

Métodos

Dental students from one university were followed for three years. The same structured questionnaire was applied in both waves of the project (in 2020 and 2023). Quality of sleep was assessed using the Pittsburgh Sleep Quality Index (PSQI), while mental health status was assessed using the Depression, Anxiety, and Stress Scale-21 (DASS-21), both validated to Brazilian-Portuguese. The outcome regarding quality of sleep was defined as having a PSQI ≥5 in both waves (always poor quality of sleep) or having a PSQI <5 in at least one wave (irregular or always good sleep quality). For this outcome, mental health status in 2020 was defined as the primary exposure. The DASS-21 categorizes individuals as normal, mild, moderate, severe, or extremely severe. For this outcome, students were dichotomized into having a normal mental health condition or presenting a better categorization in 2023 (good or improved mental health); and presenting a worsening in mental health or remaining in a non-normal category over the three years (no change or worsening in mental health status). For this outcome, sleep quality in 2020 was defined as the primary exposure. Independent analyses were performed for each outcome, using adjusted Poisson regression. Statistical significance was established at p<0.05.

Resultados

A total of 150 students were included. Mental health status in 2020 was able to predict always poor quality of sleep over the three years, with those students with at least moderate depression (relative risk [RR]:2.03; 95% confidence interval [95%CI]:1.52-2.70), anxiety (RR:1.63; 95%CI:1.22-2.17), or stress (RR:1.48; 95%CI:1.12-1.97) showing higher risks for this outcome. However, poor quality of sleep was not able to predict worsening in the mental health status in relation to depression (RR:1.25; 95%CI:0.70-2.21), stress (RR:0.85; 95%CI:0.54-1.33), and anxiety (RR:0.90; 95%CI:0.57-1.40).

Conclusões

It was concluded that dental students have a high occurrence of poor quality of sleep and mental health status. Poor quality of sleep may predict a worsening in mental health status. However, the inverse relationship was not detected.

Palavras -chave

Dental students; Mental health; Sleep quality