Cognitive impairment among patients with first-time diagnosed depressive episodes and recurrent depressive disorder

The study evaluates cognitive impairment between patients with the first depressive episode (FDE) and those with recurrent depressive disorder (RDD). The interview consists of sociodemographic information, Montreal Cognitive Scale (MoCA), the Patient Health Questionnaire-9 (PHQ-9). Data is statistically processed in MS Excel and SPSS 20. All 50 respondents complained about their cognitive function. Results indicated a positive correlation between the severity of depression and the impairment of executive function (r(50)=0.383, p=0.006) as well abstract thinking (r(50)=0.360, p=0.01) when testing on MoCA; however, the total MoCA score didn’t correlate with the depression severity on PHQ-9 scale (r(50)=0.111; p=0.443). Although patients with RDD showed considerably lower scores (M=3.39; SD=1.128) on the PHQ-9 scale than patients with FDD (M=3.39; SD=1.111) t(48)=3.005; p=0.004, there was not a significant difference of MoCA’s total score between the group with FDE (M=-0.386; SD=-0.782) and the group with RDD (M=-0.386; SD=0.753) t(48)=-0.494; p=0.624. Patients with RDD demonstrated considerably better attention (M=-1.263; SD=0.321) than the patients with FDE (M=-1.263; SD=0.328); t(48)=-0.398; p<0.005. The impairment of the executive function was worse among patients with RDD (M=0.393; SD=0.119) than FDD (M=0.393; SD=0.134); t(48)=2.294; p=0.005. The impairment of abstract thinking was not significantly different between patients with FDE (M=-0.58; SD=0.149) and RDD (M=-0.58; SD=0.145) t(48)=-0.393; p=-0.056. All patients showed difficulty remembering (mean 3.5 of max score 5); however, there was neither correlation with the severity of depression nor difference between patients with FDE and RDD. The severity of depression correlates with executive function and abstract thinking. Patients with RDD demonstrated better attention and worse executive function than the patients with FDE, but the abstract thinking was equal in both groups. All depressive patients show difficulty remembering, but it doesn’t correlate with the severity of depression and doesn’t show a difference among the patients with FDE and RDD.