Trajectories of depressive symptoms 10 years after stroke and associated risk factors: a prospective cohort study.

Background: Previous studies have investigated the risk factors for post-stroke depression at only one timepoint, neglecting its dynamic nature. We aimed to identify trajectories of post-stroke depression from multiple assessments and explore their risk factors.

Methods: We did a population-based cohort study with the South London Stroke Register (1995-2019). All stroke patients with three or more measurements of the Hospital Anxiety and Depression Scale were included. We identified trajectories of post-stroke depression over a 10-year follow-up using group-based trajectory modelling. We determined the optimal number and shape of trajectories based on the lowest Bayesian information criterion, average posterior probability of assignment of each group over 0·70, and inclusion of at least 5% of participants within each group. We used multinomial logistic regression adjusted for age, sex, ethnicity, comorbidity, physical disability, stroke severity, history of depression and cognitive impairment to explore associations with different trajectories.

Findings: The analysis comprised 1968 participants (mean age 64·9 years [SD 13·8], 56·6% male and 43·4% female, 65·1% white ethnicity, 30·7% severe disability and 32·7% severe stroke). We identified four patterns of symptoms: no depressive symptoms (14·1%, n=277), low symptoms (41·7%, n=820), moderate symptoms and symptoms worsening early and then improving (34·6%, n=681), and high and increasing symptoms (9·7%, n=190). Compared with no depressive symptom trajectory, patients with severe disability, severe stroke, pre-stroke depression, and cognitive impairment were more likely to be in the moderate and high symptom groups (adjusted odds ratios [ORs] 2·26 [95% CI 1·56-3·28], 1·75 [1·19-2·57], 2·20 [1·02-4·74], and 2·04 [1·25-3·32], respectively). Female sex was associated with high depression (OR 1·65 [1·13-2·41]), while older age (≥65 years) was associated with moderate depression (OR 1·82 [1·36-2·45]). In men, the ORs for patients with severe disability, severe stroke, pre-stroke depression, and cognitive impairment being in the high depression group were 1·91 (1·01-3·60), 2·41 (1·26-4·60), 2·57 (0·84-7·88), and 2·68 (1·28-5·60), respectively. In women, the ORs were 1·08 (0·52-2·23), 1·30 (0·60-2·79), 19·2 (2·35-156·05), and 3·80 (1·44-10·01), respectively.

Interpretation: Female sex and older age were associated with distinct courses of depressive symptoms. In men, high depressive symptom trajectory was associated with severe stroke and severe disability, which was not the case in women. These findings were limited to patients with three or more assessments, who tended to have less severe disabilities than excluded patients and might not generalise to all stroke survivors.

Funding: National Institute for Health and Care Research (NIHR).