Patients with major depressive disorder (MDD) underestimate their objective cognitive abilities, according to results published in the Journal of Affective Disorders. The findings also showed that healthy study participants serving as controls are more likely to overestimate their objective cognitive abilities.
The study included outpatients with MDD (n=102) and healthy control participants matched for age, gender, and education level (n=88). The researchers used a neuropsychological test battery and a questionnaire for the self-assessment of cognitive performance in the domains of attention, memory, and executive function.
The researchers did not find any significant associations between subjective and objective cognitive dysfunction in either the MDD group or the control group.
As expected, in the MDD group, there were significantly higher subjective cognitive impairments than objective cognitive dysfunctions in all cognitive domains (P ≤.001). The magnitude of these differences was small to moderately large, with effect sizes ranging from d =−0.41 for response inhibition to d =−0.61 for alertness.
Compared with the control group, participants in the MDD group had significantly more subjective cognitive impairment than objective cognitive dysfunction in all cognitive domains (P ≤.001). The effect sizes ranged from small to moderately large, ranging from d =−0.41 for response inhibition to d =−0.61 for alertness.
In the control group, participants performed significantly worse on neuropsychological tests than they reported subjectively (P ≤.001). The effect sizes ranged from moderate to large, from d =0.67 for divided attention to d =1.33 for alertness.
“Our findings highlight the importance of implementing neuropsychological tests when patients with MDD complain about cognitive difficulties,” the researchers wrote.
Schwert C, Stohrer M, Aschenbrenner S, Weisbrod M, Schröder A. Biased neurocognitive self-perception in depressive and in healthy persons. J Affect Disord. 2018;232:96-102.