Effortful information processing in patients with major depression - a 10-year follow-up study.

The aim of the present study was to longitudinally investigate effortful cognitive functioning in a group of patients diagnosed with major depressive disorder (MDD) in a 10-year follow-up period. Results at inclusion in the acute phase of MDD showed impaired effortful processing and that this impairment prevailed at a 6-month follow-up, despite significant symptom reduction. Non-effortful processing was normal as compared to healthy controls. Sixteen patients along with 16 healthy controls were included in the 10-year follow-up. They all participated in the original study and were matched for age and educational length. The mean symptom load at the time of testing at the 10-year follow-up indicated that the patients as a group were in remission. All participants were examined with a visual search paradigm, with demands for effortful and non-effortful processing. Results showed that the patient group had normalized their performance for effortful information processing and no longer differed significantly from the healthy controls at the 10-year follow-up, and the lack of difference between the groups for non-effortful processing remained the same. These results indicate that short-term effortful cognitive impairments normalize over the course of long-term recovery that goes together with clinical improvement and remission.