An overview of depression
A constellation of symptoms
The symptoms of depression
Depression is a clinically heterogeneous condition, with a widely underestimated variety of symptoms spanning emotional, physical and cognitive domains.1,2 While patients must present with either depressed mood or anhedonia for a diagnosis of depression to be provided, a selection of the symptoms below can also contribute to their depressed state:1
Cognitive symptoms in particular are a poorly understood aspect of depression symptomatology in clinical practice.2 In fact, even DSM-5 does not cover the full range of cognitive symptoms which present in patients with depression.1
Additional cognitive deficits seen in depression include:3-5
- Difficulty in maintaining attention
- Poor organisation/planning
- Decline in mental sharpness
- Difficulty learning new concepts
- Reduced thinking speed
- Poor judgement
- Difficulty recalling words
Cognition and depression – the facts
Cognitive symptoms are a significant component of depression in many patients, and often persist beyond the cessation of emotional manifestations like sadness, anxiety and anhedonia1:
- In a meta-analysis of 644 patients experiencing their first episode of major depression, cognitive performance was significantly impaired across domains including psychomotor speed, attention, visual learning and memory and executive function6
- In a Dutch study of 267 patients with depression, cognitive symptoms were present 94% of the time during major depressive episodes7
- In the same Dutch study, cognitive symptoms were shown to persist for an average of 44% of the time during periods of ‘remission’7