Effects of symptom reduction and psychotropic medication on cognitive impairment in depression

Depression is related to cognitive performance. This follow-up study examines the influence of depression symptoms and psychopharmacological treatment on change in the cognitive performance of patients with depressive episodes over a 2-year period.

Sixty-two in- and outpatients with depression of varying severity (ICD-10: F31-F33) were examined in an open prospective naturalistic observational study with 3 points of measurement and tested by use of 3 computerized cognitive performance tests [Visual Attentiveness Test (VAT), Continuous Attention Test (CAT), Word Recognition Test (WRT)], while the psychotropic medication was classified by subclass and dosage. Statistical analysis was performed by random-effects regression models.

The raw values of VAT speed, CAT speed and WRT quality improved over time. However, the positive time trend disappeared after the patients' clinical and personal characteristics were controlled for. The processing speed of the VAT was found to be negatively influenced by depressive symptoms. That of the CAT developed favorably with increasing level of education. The performance qualities of the VAT, WRT and CAT were positively related to the participants' educational level. The patients who received antipsychotic treatment performed worse on WRT quality than those who were not treated with antipsychotics.

The cognitive performance was relatively stable during the treatment process and not affected by clinical characteristics or type of medication. Cognitive deficits in patients with depression could be a trait rather than a state marker.