Background: Major Depressive disorder (MDD) is often accompanied by
cognitive deficits, involving attention, learning, memory and executive functioning.
Selective Serotonin Reuptake Inhibitors (SSRIs) and Serotonin and Noradrenaline
Reuptake Inhibitors (SNRIs) show efficacy on affective symptoms, but it is unclear
whether or not they improve cognitive symptoms.
Methods: We carried out a 12 week-prospective observational study in two cohorts
of recurrent moderate-severe partial responder MDD patients, to test the hypothesis
that SSRIs and/or SNRIs may affect cognitive symptoms and assess whether or not
such an effect was correlated to their effect on affective symptoms. All patients
underwent cognitive and neuropsychiatric assessment at baseline, 4- and 12-week
follow-up. Thirty-three patients in the SSRI- and sixteen patients in the SNRI-cohort completed the follow-up.
Results: Both SSRIs and SNRIs reduced affective symptoms and improved global cognitive function.
Both SSRIs and SNRIs improved executive function and verbal memory. Global cognitive function,
verbal memory and executive function improved both in full and partial responder patients. Finally,
there was no correlation between baseline Mini Mental State Examination, Montreal Cognitive
Assessment and Frontal Assessment Battery scores and the mean change in Hamilton Psychiatric Rating
scale for Depression or Beck Depression Inventory at the end of the 12 weeks of treatment.
Conclusion: Present data show that SSRIs and SNRIs improve cognitive symptoms in MDD
independently from their efficacy on affective symptoms. Affective and cognitive symptoms may represent
distinct psychopathological dimensions of MDD with different response to antidepressant drugs.