Cognitive Function And Slee Characteristics In Young And Middle-Aged Patients With Major Depressive Disorder

Objective:1. To explore the feature of cognitive impairment in adolescence and middle-aged patients with major depression disorder(MDD).2. To investigate the objective sleep features and clinical features and the differences between objective and subjective sleep quality.Methods:40 MDD patients with first-episode were collected continuously in Neuropsychology Clinic in General Hospital of Tianjin Medical University. MDD patients met the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition(DSM-IV), while 34 healthy controls were collected continuously in Physical Examination Center with age, gender and schooling matched. The Mini International Neuropsychiatric Interview(M.I.N.I.) was used as a diagnostic tool. The Hamilton Rating Scales of Depression-17(HAMD-17) was used to assess depression severity. The cognitive function was evaluated with animal fluency test(AFT), symbol digit modalities test(SDMT), Hopkins verbal learning test-revised(HVLT-R), brief visuospatial memory test-revised(BVMT-R), Stroop color word test(SCWT) and trail making test(TMT) to analysis the cognitive impairment features of MDD. For the secondary analysis, the subjects were divided into adolescence group(18 to 40 years old) and middle-aged(40 to 60 years old) group.15 MDD patients with clinical symptoms of insomnia( Insomnia is a subjective experience that refers to patients who discontent the sleep time and/or quality and influence social function during the day), while 15 healthy controls were collected continuously with age, gender and schooling matched. The Pittsburgh Sleep Quality Index( PSQI) was used to assess subjective sleep quality and laboratory polysomnography(PSG) was used to assess Objective sleep quality.Results:1. The neuropsychological characteristics of MDD patientsThe scores of HVLT-R, BVMT-R, AFT and SDMT of MDD group were significantly lower than those of the control group(p <0.05); the scores of TMTA, TMTB were significantly higher than those of the control group(p<0.05). In the adolescence group, the scores of HVLT-R, AFT and SDMT of MDD group were significantly lower than those of the control group; the scores of TMTA, TMTB were significantly higher than those of the control group; the scores of delayed recall and total learning number of BVMT-R were significantly lower than those of the control group. In the middle-aged group, the scores of total learning number of BVMT-R and AFT were significantly lower than those of the control group.2. The characteristics of sleep disorders in patients with MDD patientsIn the aspect of subjective sleep, the scores of Sleep latency, sleep maintena-n ce rate, sleep efficiency, sleep quality, daytime function and sleeping pill of MDD group were significantly higher than those of the control group(p<0.05). In the aspect of objective sleep, At process and continuity of sleep: In the case of the two groups having the same total recorded time(TRT)(p>0.05), sleep latency(SL), awakening time(AT) and awake sleep ratio(ASR) of MDD group were longer than the control group(p<0.05). And total sleep time(TST), sleep efficiency(SE) and sleep maintenance(SM) were shorter than the control group(p<0.05); At sleep structure: N1% in MDD group was longer than the control group, N2% and N3% were shorter than the control group(p<0.05); At rapid eye movement(REM) index: REM latency(RL) of MDD group was shorter than the control group. And REM activity(RA), REM intensity(RI) and REM density(RD) were higher than the control group(p<0.05-0.01). There was no obvious difference in REM sleep time(RT) between the MDD group and the control group(p>0.05).3 The differences between objective and subjective sleep quality in MDD patientsThere was a discrepancy of actual sleep time and sleep efficiency between subjective and objective sleep in MDD patients: The subjective sleep time(343 ± 13) vs.( 443±23)(P=0.002) and sleep efficiency(62 ± 3)vs.( 74±3)(P=0.001) showed a significant lower than the objective indictors. There was no obvious difference in sleep latency between objective and subjective sleep, although sleep latency of subjective sleep was longer than that of objective sleep.Conclusion:1. The main domains of cognitive impairment of patients with MDD are memory, attention and executive function.2. The cognition of young MDD patients was extensively impaired. The spatial memory and psychomotor speed were impaired in middle-aged MDD patients.3. Insomnia symptoms in MDD patients were similar to the ordinary insomnia patients. Polysomnografy characteristics had significant changes in sleep process, sleep structure and REM indicators. And change of REM sleep characteristics may be the specificity.4. The MDD patients lacked satisfaction with the subjective sleep quality and they might overstate the severity of insomnia. There were significant differences between subjective and objective sleep quality.