The natural history of depression and trajectories of symptoms long term after stroke: The prospective south London stroke register.

Background: The natural history of depression in stroke patients is complex and the mechanism of change in symptoms over time is not fully understood. We hypothesise that there are different trajectories of symptoms after stroke.

Methods: The primary analysis comprised 761 patients who completed 5 years follow up, obtained from the prospective South London Stroke Register (1998-2013). The Hospital Anxiety and Depression scale (HADs) was used to screen patients for depression symptoms at 3 months after stroke, then annually. Trajectories of depression symptoms were detected using group based trajectory modelling (GBTM).

Results: Four patterns of symptoms (Groups I-IV) were identified: 6.31% of patients had severe symptoms, improved slightly in early years then worsen (predicted mean HADs score, 15.74 (se=1.06)); 28.65% had moderate symptoms, a tendency to get worse over time, predicted mean score 7.36 (se=0.35); 49.54% had mild symptoms and a tendency of getting worse, predicted mean 3.89 (se=0.30), and 15.51% of the cohort, had no symptoms and remained so over time. The lowest rate of Selective serotonin reuptake inhibitors (SSRI) use, over 5 years after stroke was 1.1% for group (I) and highest was 35% for group (IV). Sensitivity analyses were used to assess the robustness of the findings using several inclusion criteria and findings agreed with the primary results.

Limitations: There is loss to follow up of around 20%.

Conclusions: The study identified 4 trajectories of depression symptoms, providing useful information for the long term management of stroke patients and for the implementation of cost effective personalized interventions.