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

 

 

 

 

Professor McIntyre explores the prevalence of cognitive symptoms during episodes of depression and remission

References

  1. American Psychiatric Association. Diagnostic and Statistical Manual of Mental Health Disorders. 5th Washington, DC: American Psychiatric Association; 2013.
  2. Jarema M et al. Cognitive dysfunction in depression – underestimated symptom or a new dimension? Psychiatr Pol 2014; 48(6): 1105-1116.
  3. Marazziti D et al. Cognitive impairment in major depression. Eur J Pharmacol 2010; 626(1): 83-86.
  4. Hammar A, Ardal G. Cognitive functioning in major depression – a summary. Front Human Neurosci 2009; 3-26.
  5. Fehnel SE et al. Patient-centered assessment of cognitive symptoms in depression. CNS Spectr 2013; 25:1-10.
  6. Lee RSC et al. A meta-analysis of cognitive deficits in first-episode Major Depressive Disorder. J Affect Disord 2012; 140: 113-124.
  7. Conradi HJ et al. Presence of individual (residual) symptoms during depressive episodes and periods of remission: a 3-year prospective study. Psychol Med 2011; 41(6): 1165-1174.