Impact of subjective vs. objective remission status on subjective cognitive impairments in depression

Objective: The impact of subjective vs. objective illness severity on subjective cognitive impairment in patients with depression has not been addressed. Methods: This study is a post-hoc analysis of our cross-sectional study in Japanese outpatients with depressive disorder (ICD-10) (Ozawa et al., 2017). The participants received assessments with the Japanese version of the Perceived Deficits Questionnaire (J-PDQ), Quick Inventory of Depressive Symptomatology (QIDS), and Montgomery–Asberg Depression Rating Scale (MADRS). First, multiple regression analysis was conducted to examine the effects of demographic and clinical characteristics, including illness severity and medications (e.g., antidepressants and benzodiazepines), on the PDQ total score. Next, we categorized the participants into 4 groups based on the presence/absence of subjective and objective symptom remission (i.e., QIDS total score of ≤5 and MADRS total score of ≤9, respectively), and compared the differences in PDQ total scores between the QIDS- and MADRS-remitted group and the QIDS-non-remitted but MADRS-remitted group. Results: 102 participants were included (45 men; mean ± SD age, 50.5 ± 14.7 years). Higher QIDS and MADRS total scores were significantly associated with a greater PDQ total score (both p's < 0.001), while other factors did not exhibit any associations. The QIDS-non-remitted but MADRS-remitted group showed a significantly higher PDQ total score than that of the QIDS- and MADRS-remitted group (median 10.0 [8.0–12.0] vs. 3.0 [range: 2.0–4.0], p < 0.001). Conclusions: These findings suggest that objective remission in the absence of subjective remission may not be adequate to improve subjective cognitive functioning.