Memory awareness in patients with Major Depressive Disorder

Area of Science:

• Neuroscience
• Psychiatry
• Cognitive Psychology

Background:

• Subjective Memory Complaints (SMC) and cognitive deficits are common in Major Depressive Disorder (MDD).
• The interplay between perceived memory issues and actual memory performance in MDD is not fully understood.
• This study compares SMC and objective memory in MDD, Mild Cognitive Impairment due to Alzheimer's Disease (MCI-AD), and healthy controls (HC).

Purpose of the Study:

• To investigate the relationship between subjective memory complaints and objective memory performance in patients with MDD.
• To differentiate the memory self-awareness patterns in MDD from those in MCI-AD and HC.
• To assess the correlation between memory complaints and depressive symptoms.

Main Methods:

• Recruited 47 MDD patients, 43 MCI-AD patients, and 45 HC.
• Administered a self-report memory complaints scale (SMCS) and conducted comprehensive neuropsychological assessments.
• Calculated a discrepancy score between Logical Memory delayed recall and SMCS total score to measure memory awareness.

Main Results:

• MDD (12.5 ± 4.4) and MCI-AD (10.9 ± 4.1) patients reported similar high levels of memory complaints, unlike HC (4.0 ± 3.0).
• A significant proportion of MDD (74.5%) and MCI-AD (65.1%) patients experienced prominent memory complaints, versus only 4.4% of HC.
• MDD patients demonstrated relatively preserved memory test performance, leading to a higher discrepancy score (indicating poorer memory awareness) than MCI-AD and HC groups.

Conclusions:

• Patients with MDD exhibit inaccurate memory self-awareness, underestimating their memory functioning.
• This pattern of underestimation distinguishes MDD from MCI-AD and HC.
• Memory complaints in MDD correlate positively with depressive symptom severity across all groups.