Cognitive impairment in euthymic major depressive disorder: a meta-analysis

Area of Science:

• Neuroscience
• Psychiatry
• Cognitive Psychology

Background:

• Cognitive deficits may persist after acute illness in major depressive disorder (MDD).
• Existing research findings on cognitive deficits in MDD are inconsistent.
• This study systematically reviews and meta-analyzes cognition in euthymic (remitted) MDD patients.

Purpose of the Study:

• To conduct a systematic review and meta-analysis of cognitive function in euthymic adult MDD patients.
• To compare cognitive performance between euthymic MDD patients and healthy controls.
• To examine the influence of demographic variables and clinical factors on cognitive deficits in MDD.

Main Methods:

• Systematic literature search across multiple databases.
• Meta-analysis of 27 empirical studies (895 MDD patients, 997 controls).
• Analysis of cognitive domains including executive functions, memory, and processing speed.

Main Results:

• Euthymic MDD patients exhibited significantly poorer cognitive functions than healthy controls.
• Deficits were generally modest, except for inhibitory control.
• Late-onset MDD cases showed more pronounced deficits in verbal memory, processing speed, and executive functions.

Conclusions:

• Poor response inhibition is a likely persistent feature in some forms of adult-onset MDD.
• Cognitive deficits are more common in late-onset depression, suggesting potential vascular or neurodegenerative roles.
• Further research is needed for remitted psychotic, melancholic, and bipolar spectrum MDD.