Understanding the incidence and recurrence of depression and associated risk factors in 9 years of follow-up: Results from a population-based sample

Abstract

Introduction

This paper aims to analyse depression incidence and recurrence rates in a Spanish adult cohort, while also investigating associated risk factors based on depression status at baseline.

Methods

Longitudinal, prospective study data of the Edad con Salud cohort was used, which comprises a sample representative of the non-institutionalized adult populace at the national level with a final sample size of 2655 Spanish adults. Competing risk regression models were estimated to determine the main risk factors for incident and recurrent depression.

Results

The study found depression incidence at 6.11 per 1,000 person years, with recurrence rates up to 47.8 and 21.3 per 1,000 person years in those with depression at baseline and only history of depression, respectively, with higher rates found among women. Sociodemographic factors were found to primarily predict incident depression, while health and mental health indicators were significant predictors for recurrent depression.

Conclusions

Our results confirm the augmented risk of experiencing a new episode among individuals with proximal depression, where different risk factors seemed to play a role depending on episode type and depression proximity. These findings provide valuable insights for developing preventive strategies for depression in both the general population and those at risk.