ABSTRACT
Objective To explore memory function affected by chronic insomnia. Methods Fiftyfive patients with primary insomnia (PI), 119 patients with comorbidity of depression and insomnia (CDI)and 50 normal individuals were enrolled. Objective memories, including spatial working memory, spatial reference memory, objective working memory and object reference memory, were detected by nine boxes maze, and subjective memory was assessed by themselves on a 5-point scale ranging from 0 ( extremely severe problem) to 4 (no problem). Results Compared to the controls, the self-evaluated memory ( 1( 1,2 ) ) was worse in the mild PI patients, and the spatial working memory ( 6 ( 2. 5,11 ) ) was also worse in the severe PI patients( ×2 = 4. 526,3. 529, both P ＜ 0. 01 ). For the CDI, the self-evaluated memory ( 2 ( 1,2) ) and spatial working memory (6(3,10)) were worse in the mild patients(×2 =5. 803,4. 155 ,both P ＜0. 01 ). However, the object ( 0. 5 (0,1) ) and spatial reference ( 1.5 ( 1, 3 ) ) memories were also worse in the severe patients ( ×2 =2. 641,3. 955 ,both P ＜0. 01 ). Conclusions PI damages subjective memory and the severe PI also damages spatial working memory. CDI damages various memory functions, especially in severe CDI patients, including subjective memory, object reference memory, spatial reference memory and spatial working memory.