Wake Up Time, Light, and Mood in a Population Sample Age 40–64 Years

Takuro Endo,Daniel F. Kripke,Sonia Ancoli-Israel 대한신경정신의학회 2015 PSYCHIATRY INVESTIGATION Vol.12 No.2

Objective-Concern that disturbances of sleep and light exposures at night might increase cancer risks have been expressed, but little actual exposure data has been collected. Measurements from a representative population sample were examined to understand the magnitude of in-bed light exposure at night and possible correlates. Methods-From 1990 to 1994, a home survey of sleep disorders among adults ages 40–64 was conducted in the City of San Diego California, using stratified representative sampling techniques. Along with questionnaires, sleep logs, and 3-night wrist activity and pulse oximetry measures, bedside illumination was measured with a computer recording system. Questionnaires included the CESD depression scale and a scale of symptoms typical of winter depression. Results-Complete data were available from 286 men and women, whose mean in-bed intervals averaged 7 hours and 42 minutes. The mean room illumination during the first part of the night was mean 12.7 lux (median 3.2 lux) and during the last 2 hours in bed averaged 28.7 lux (median 18.9 lux). Nocturnal light exposure was positively correlated with age, male gender, summer season, time in bed, wake-up time, and depressive symptoms. Conclusion-Complex bi-directional interactions may take place between sleep disturbances, depression, time in bed, wake-up-time, and in-bed illumination. The most crucial light exposures appear to occur in the last 2 hours in bed, largely after dawn, so daylight exposure may be an important factor.

Genotyping Sleep Disorders Patients

Daniel F. Kripke,Farhad F. Shadan,Arthur Dawson,John W. Cronin,Shazia M. Jamil,Alexandra P. Grizas,James A. Koziol,Lawrence E. Kline 대한신경정신의학회 2010 PSYCHIATRY INVESTIGATION Vol.7 No.1

Objective: The genetic susceptibility factors underlying sleep disorders might help us predict prognoses and responses to treatment. Several candidate polymorphisms for sleep disorders have been proposed, but there has as yet inadequate replication or validation that the candidates may be useful in the clinical setting. Methods: To assess the validity of several candidate associations, we obtained saliva deoxyribonucleic acid (DNA) samples and clinical information from 360 consenting research participants who were undergoing clinical polysomnograms. Ten single nucleotide polymorphisms (SNPs) were genotyped. These were thought to be related to depression, circadian sleep disorders, sleep apnea, restless legs syndrome (RLS), excessive sleepiness, or to slow waves in sleep. Results: With multivariate generalized linear models, the association of TEF rs738499 with depressive symptoms was confirmed. Equivocal statistical evidence of association of rs1801260 (the C3111T SNP in the CLOCK gene) with morningness/eveningness and an association of Apolipoprotein E (APOE) rs429358 with the Epworth Sleepiness Scale (ESS) were obtained,but these associations were not strong enough to be of clinical value by themselves. Predicted association of SNPs with sleep apnea, RLS, and slow wave sleep were not confirmed. Conclusion: The SNPs tested would not, by themselves, be of use for clinical genotyping in a sleep clinic.

Circadian Polymorphisms in Night Owls, in Bipolars, and in Non-24-Hour Sleep Cycles

Daniel F Kripke,Walter T. Klimecki,Caroline M. Nievergelt,Katharine M Rex,Sarah S. Murray,Tatyana Shekhtman,Gregory J. Tranah,Richard T. Loving,이헌정,이민규,Farhad F. Shadan,J. Steven Poceta,Shazia M. Jami 대한신경정신의학회 2014 PSYCHIATRY INVESTIGATION Vol.11 No.4

People called night owls habitually have late bedtimes and late times of arising, sometimes suffering a heritable circadian disturbance called delayed sleep phase syndrome (DSPS). Those with DSPS, those with more severe progressively-late non-24-hour sleep-wake cycles, and those with bipolar disorder may share genetic tendencies for slowed or delayed circadian cycles. We searched for polymorphisms associated with DSPS in a case-control study of DSPS research participants and a separate study of Sleep Center patients undergoing polysomnography. In 45 participants, we resequenced portions of 15 circadian genes to identify unknown polymorphisms that might be associated with DSPS, non-24-hour rhythms, or bipolar comorbidities. We then genotyped single nucleotide polymorphisms (SNPs) in both larger samples, using Illumina Golden Gate assays. Associations of SNPs with the DSPS phenotype and with the morningness-eveningness parametric phenotype were computed for both samples, then combined for meta-analyses. Delayed sleep and “eveningness” were inversely associated with loci in circadian genes NFIL3 (rs2482705) and RORC (rs3828057). A group of haplotypes overlapping BHLHE40 was associated with non-24-hour sleep-wake cycles, and less robustly, with delayed sleep and bipolar disorder (e.g., rs34883305, rs34870629, rs74439275, and rs3750275 were associated with n=37, p=4.58E-09, Bonferroni p=2.95E-06). Bright light and melatonin can palliate circadian disorders, and genetics may clarify the underlying circadian photoperiodic mechanisms. After further replication and identification of the causal polymorphisms, these findings may point to future treatments for DSPS, non-24-hour rhythms, and possibly bipolar disorder or depression.

Evaluation of Two Circadian Rhythm Questionnaires for Screening for the Delayed Sleep Phase Disorder

MinKyu Rhee,HeonJeong Lee,Katharine M. Rex,Daniel F. Kripke 대한신경정신의학회 2012 PSYCHIATRY INVESTIGATION Vol.9 No.3

Objective-Delayed sleep phase disorder (DSPD) is a condition in which patients often fall asleep some hours after midnight and have difficulty waking up in the morning. Circadian chronotype questionnaires such as Horne-Östberg Morningness-Eveningness Questionnaire (MEQ) and Basic Language Morningness (BALM) scale have been used for screening for DSPD. This study was to evaluate these two chronotype questionnaires for screening of DSPD. Methods-The study samples were 444 DSPD and 438 controls. Cronbach’s alpha coefficient was calculated to evaluate for internal consistency. An exploratory factor analysis was conducted using principal-axis factoring. The diagnostic performance of a test was evaluated using Receiver Operating Characteristic (ROC) curve analysis. A discriminant function analysis was also performed. Results-For internal consistency, Cronbach’s alpha of 0.898 for BALM was higher than the 0.837 for MEQ, though both have acceptable internal consistency. BALM has better construct validity than the MEQ because some MEQ items measure different dimensions. However, when we evaluated the efficiency of two questionnaires for DSPD diagnosis by using the ROC curve, the BALM was similar to the MEQ. In a discriminant analysis with the BALM to classify the two groups (DSPD vs. normal), 6 items were identified that resulted in good classification accuracy. Upon examination of the classification procedure, 94.2% of the originally grouped cases were classified correctly. Conclusion-These findings suggest that the BALM has better psychometric properties than the MEQ in screening and discriminating DSPS.

Hypnotics Versus the Alternatives

Daniel F. Kripke 대한신경정신의학회 2007 PSYCHIATRY INVESTIGATION Vol.4 No.2

When patients ask for hypnotics (sleeping pills), what should physicians advise? This review considers cognitive-behavioral therapy and hypnotics as alternative treatments. The effectiveness of cognitive-behavioral therapy for insomnia has been demonstrated. No appreciable risks have been reported. The risks of hypnotics include impairments of cognition and function, depression, cancer, and early mortality, but the newest hypnotics have surprisingly little objective benefit. The physician can help patients best by persuading them of the benefits of cognitive-behavioral approaches.

Self-Reported Sleep Latency in Postmenopausal Women

Girardin Jean Louis,Melville R Klauber,Doo Heum Park,Daniel F Kripke,Jeffrey A Elliott,Katharine M Rex,Arja Tuunainen,Robert D Langer 대한의학회 2007 Journal of Korean medical science Vol.22 No.6