정신병 증상을 보이지 않는 경도 및 중등도 주요우울증 환자의 인지기능 저하 및 항우울제 치료 후 인지기능 회복 양상에 관한 전향적 연구

Cognitive Dysfunction and Improvement after Antidepressant Treatment in Patients with Non-Psychotic Major Depressive Disorder in Mild to Moderate Severity : A Prospective Study

  본 연구에서는 정신병적 증상이 없는 경도 및 중등도 주요우울증 여성 환자 15명을 대상으로 항우울제의 영향을 배제한 상태에서 언어적 기억력, 시공간 능력, 시각적 기억력, 갈등 조절, 실행 능력 등의 인지기능을 평가하였다. 치료전 평가에서는 주로 언어적 기억력의 저하 소견을 관찰할 수 있었으며 기존의 단극성 우울증에서 가장 주요한 인지기능 이상으로 알려져 있던 실행 능력의 저하는 명확히 관찰되지 않았다. 또한 시각 정보 처리 능력 및 시공간적 기억력에서도 그 기능 저하가 확실하지 않았다. 항우울제를 이용한 치료 후 우울증의 증상 호전이 이루어진 12개월 후에는 WCST의 오류 반응과 보속증의 호전이 가장 뚜렷하게 관찰되었으나 우울증상의 호전도와 직접적인 상관관계는 보이지 않았다.

  Objective : This study was conducted to evaluate the impairment of cognitive functions, which include verbal and visual memory, visuospatial function, and executive function, and also to investigate if there is improvement of cognitive impairment after antidepressant treatment in patients with major depressive disorder (MDD). Methods: Fifteen female patients with non-psychotic MDD in mild to moderate severity and 25 age-matched female normal control subjects participated in this study. Clinical severity of depression was measured by Beck Depression Inventory (BDI), Zung"s Self-Rating Depression Scale (Zung), and Hamilton Rating Scale for Depression (HAMD). Cognitive functions were tested using Ray Complex Figure Test (RCFT) to evaluate visuospatial function and visual memory, Stroop test to evaluate conflict monitoring, Wisconsin Card Sorting Test (WCST) to evaluate executive function, and Seoul Verbal Learning Test (SVLT) to evaluate verbal memory. Both clinical depression scales and cognitive function tests were conducted at baseline and after 12 months of antidepressant treatment. Results : At baseline, there were deficits in immediate and delayed recall of SVLT in patients with MDD compared to normal control subjects, while the impairment in visuospatial function, visual memory, and executive function was not clear. After antidepressant treatment, improvement of executive function, i.e, percent of error response and perseverative response of WCST in MDD patients was greater than that in normal control subjects. Improvement of executive function, however, did not show a significant correlation with the change of clinical severity of depression. Conclusion : The verbal memory was the most prominent domain of cognitive dysfunction in non-psychotic depression with mild to moderate severity. Of further note, differential improvement in executive function was observed in MDD patients after antidepressant treatment, although the improvement in executive function was not directly associated with the improvement of clinical depression.