***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: This study consisted of secondary analyses of data from 2 r and omized clinical trials to test whether pretherapy cognitions predict CBT outcomes . The sample consisted of 155 primary insomnia patients with sleep maintenance complaints . Of these , 98 were r and omized to CBT , 23 were assigned to progressive muscle relaxation training ( PMR )  , and 34 were assigned to a control ( sham therapy or wait-list ) condition ( CON ) . All patients completed the Dysfunctional Beliefs and Attitudes about Sleep Scale ( DBAS ) , a sleep-related Self-Efficacy Scale ( SES ) and nightly sleep diaries for 2 weeks prior to receiving their assigned treatment . They then completed sleep diaries throughout an 8-week acute treatment period and during a 2-week period at a posttherapy follow-up . A subset of the sample ( n=67 ) also completed  polysomnography  immediately before and after completing their assigned treatment . Preliminary regression analyses conducted with a small subset ( n=15 ) of the patients receiving CBT showed those with relatively high levels of unhelpful sleep-related beliefs ( Type 1 patients ) , as reflected by their pretherapy responses to the DBAS and SES question naires , showed markedly greater reductions in nocturnal wakefulness in response to CBT than did those ( Type 2 patients ) reporting less pronounced sleep-related beliefs . Given these findings , we used the regression equation derived from our initial analyses to dichotomize our entire sample into Type 1 ( n=82 ; 52.9 % ) and Type 2 ( n=73 ; 47.1 % ) subgroups . Subsequent comparisons showed CBT-treated Type 1 patients had significantly less wake time after sleep onset during most of the 8-week treatment phase than did the Type 1 and 2 individuals assigned to either PMR or CON . Relative to patients assigned to the PMR and CON conditions , CBT-treated Type 1 patients showed better performance across multiple subjective and objective benchmarks of clinical ly significant improvement , whereas the CBT-treated Type 2 patients did not . Results suggest that insomnia patients ' pretherapy cognitive dispositions predict CBT outcome , and those with a pronounced sense of sleep-related helplessness are best suited for this treatment which targets this cognitive stance In a prospect ive-longitudinal study of a representative birth cohort , we tested why stressful experiences lead to  depression  in some people but not in others . A functional polymorphism in the promoter region of the serotonin transporter ( 5-HT T ) gene was found to moderate the influence of stressful life events on depression . Individuals with one or two copies of the short allele of the 5-HT T promoter polymorphism exhibited more depressive symptoms , diagnosable depression , and suicidality in relation to stressful life events than individuals homozygous for the long allele . This epidemiological study thus provides evidence of a gene-by-environment interaction , in which an individual 's response to environmental insults is moderated by his or her genetic makeup OBJECTIVE The purpose of this study was to examine whether there is a bidirectional relationship between , on one h and , anxiety and depression and , on the other h and , insomnia over the course of a year . METHODS A r and omly selected sample of 3000 participants from the general population filled out a  baseline survey ( N=1812 ) and a 1-year follow-up survey ( N=1498 ) on  anxiety , depression , and insomnia .  RESULTS On cross-sectional analyses , bivariate correlations showed that anxiety , depression , and insomnia were significantly intercorrelated ( varphi=.31-.54 ) . On prospect i ve analyses , logistic regression analyses demonstrated that anxiety at baseline [ odds ratio (OR)=4.27 ( 8 % of variance ) ] and depression at baseline [ OR=2.28 ( 2 % of variance ) ] were related to new cases of insomnia on follow-up . Furthermore , insomnia at baseline was related to new episodes of high anxiety and high depression on follow-up [ OR=2.30 ( 2 % of variance ) and OR=3.51 ( 4 % of variance ) , respectively ] . CONCLUSION Evidence suggests that there is a bidirectional relationship between , on one h and , anxiety and depression and , on the other h and , insomnia . This suggests that anxiety , depression , and insomnia are intertwined over time , implying implication s for theoretical conceptualizations and interventions The aims of this study were to measure the error in sleep estimation in normal controls and subjects with primary insomnia to establish the minimum amount of sleep needed for reliable subjective estimation and to depict the distribution of the error in sleep estimation in both groups . A two-step retrospective ( study 1 ) and prospect i ve ( study 2 ) validation study was carried out . Study 1 included 288 normal subjects [ 176 females and 112 males , mean age 58.5 years , st and ard deviation ( SD ) 7.23 ] . Study 2 included 159 patients ( 98 females and 61 males ; mean age 49.1 years , SD 12.71 ) with primary insomnia . Participants underwent a full-night polysomnographic study , followed by a morning assessment of subjective sleep parameters .  A misperception index ( MI ) was computed using the following formula : MI = [ objective total sleep time (oTST)-subjective total sleep time (sTST)]/oTST . The statistical properties of this index were analysed in detail in both groups . In controls , the Bl and -Altman test demonstrated the reliability of this index for values of oTST > 120 min . Healthy subjects estimated their sleep time correctly , while insomniacs largely underestimated their sleep time . Statistical analysis of the distribution of MI in insomnia patients disclosed the presence of two subgroups , one with moderate sleep misperception ( 132 patients ) and the other with high sleep misperception ( 27 patients ) . The latter presented MI values > or=0.9 , exhibiting statistical properties different from those with MI < 0.9 and from normal subjects . The MI gives a reliable and immediate description of sleep misperception in healthy and insomnia subjects . Its application supports the existence of the high misperception of insomnia as a separate pathological entity STUDY OBJECTIVE To examine the association between depression and three subtypes of insomnia , namely , difficulty initiating sleep ( DIS ) , early morning awakening ( EMA ) , and difficulty maintaining sleep ( DMS ) . DESIGN Cross-sectional and longitudinal study . SETTING Community dwellers in Japan . PARTICIPANTS Nationally representative sample s of adults aged 65 and over ( total N=4,997 ) were selected by a multistage stratified r and om sampling method in 1999 and were interviewed face-to-face in 1999 , 2001 , 2003 , and 2006 . Those who responded to the 3rd survey conducted in 2003 and the 4th survey conducted in 2006 were used in this study . MEASUREMENT AND RESULTS Depression was evaluated according to the 11-item short form of the CES-D scale at 2 points in time . Insomnia subtypes were assessed by self-reported measures . A logistic regression was employed to examine the association between insomnia subtypes and the presence of depression , controlling for relevant factors . A cross-sectional analysis based on the 2003 data demonstrated statistically significant odds ratios ( ORs ) for DIS and EMA . In the longitudinal study , DIS at the time of the 3rd survey was found to be significantly related to the presence of depression at the time of the 4th survey , with an odds ratio ( 95%CI ) of 1.592 ( 1.012 to 2.504 ) . EMA ( OR 1.070 ; 95 % CI , 0.664 to 1.723 ) and DMS ( OR 1.215 ; 95 % CI , 0.860 to 1.716 ) , however , were not found to be significantly related to the presence of depression . CONCLUSION The longitudinal study revealed a statistically significant relationship , controlling for other relevant factors , between DIS and the presence of depression three years later , but not between EMA or DMS and depression . Based on our findings , we recommend that the association between insomnia subtypes and depression be studied longitudinally in clinical setting Background Psychiatric distress and insomnia symptoms exhibit similar patterning by gender and socioeconomic position . Prospect i ve evidence indicates a bi-directional relationship between psychiatric distress and insomnia symptoms so similarities in social patterning may not be coincidental . Treatment for insomnia can also improve distress outcomes . We investigate the extent to which the prospect i ve patterning of distress over 20 years is associated with insomnia symptoms over that period . Methods 999 respondents to the Twenty-07 Study had been followed for 20 years from approximately ages 36–57 ( 73.2 % of the living baseline sample ) .  Psychiatric distress  was measured using the GHQ-12 at baseline and at 20-year follow-up . Gender and social class were ascertained at baseline . Insomnia symptoms were self-reported approximately every five years . Latent class analysis was used to classify patterns of insomnia symptoms over the 20 years . Structural Equation Models were used to assess how much of the social patterning of distress was associated with insomnia symptoms . Missing data was addressed with a combination of multiple-imputation and weighting . Results Patterns of insomnia symptoms over 20 years were classified as either healthy , episodic , developing or chronic . Respondents from a manual social class were more likely to experience episodic , developing or chronic patterns than those from non-manual occupations but this was mostly explained by baseline psychiatric distress . People in manual occupations experiencing psychiatric distress however were particularly likely to experience chronic patterns of insomnia symptoms . Women were more likely to experience a developing pattern than men , independent of baseline distress . Psychiatric distress was more persistent over the 20 years for those in manual social classes and this effect disappeared when adjusting for insomnia symptoms . Irrespective of baseline symptoms , women , and especially those in a manual social class , were more likely than men to experience distress at age 57 . This overall association for gender , but not the interaction with social class , was explained after adjusting for insomnia symptoms . Sensitivity analyses supported these findings . Conclusions Gender and socioeconomic inequalities in psychiatric distress are strongly associated with inequalities in insomnia symptoms . Treatment of insomnia or measures to promote healthier sleeping may therefore help alleviate inequalities in psychiatric distress BACKGROUND AND PURPOSE To estimate the prevalence of  insomnia symptoms and syndrome in the general population , describe the types of self-help treatments and consultations initiated for insomnia , and examine help-seeking determinants . PATIENTS AND METHODS A r and omly selected sample of 2001 French-speaking adults from the province of Quebec ( Canada ) responded to a telephone survey about sleep , insomnia , and its treatments .  RESULTS Of the total sample , 25.3 % were dissatisfied with their sleep , 29.9 % reported insomnia symptoms , and 9.5 % met criteria for an insomnia syndrome . Thirteen percent of the respondents had consulted a healthcare provider specifically for insomnia in their lifetime , with general practitioners being the most frequently consulted . Daytime fatigue ( 48 % ) , psychological distress ( 40 % ) , and physical discomfort ( 22 % ) were the main determinants prompting individuals with insomnia to seek treatment . Of the total sample , 15 % had used at least once herbal/dietary products to facilitate sleep and 11 % had used prescribed sleep medications in the year preceding the survey . Other self-help strategies employed to facilitate sleep included reading , listening to music , and relaxation . CONCLUSIONS These findings confirm the high prevalence of insomnia in the general population . While few insomnia sufferers seek professional consultations , many individuals initiate self-help treatments , particularly when daytime impairments such as fatigue become more noticeable . Improved knowledge of the determinants of help-seeking behaviors could guide the development of effective public health prevention and intervention programs to promote healthy sleep STUDY OBJECTIVES To determine whether the frequency spectrum of the sleep EEG is a physiologic correlate of 1 ) the degree to which individuals with persistent primary insomnia ( PPI ) underestimate their sleep time compared with the traditionally scored polysomnogram ( PSG ) and 2 ) the sleep complaints in PPI subjects who have relatively long traditionally scored PSG sleep times and relatively greater underestimation of sleep time . DESIGN We compared EEG frequency spectra from REM and NREM sleep in PPI subjects subtyped as subjective insomnia sufferers ( those with relatively long total sleep time and relative underestimation of sleep time compared with PSG ) , and objective insomnia sufferers ( those with relatively short PSG total sleep time ) with EEG frequency spectra  in normals . We also studied the correlation between these indices and the degree of underestimation of sleep . Further , we determined the degree to which sleep EEG indexes related to sleep complaints . SETTING Duke University Medical Center Sleep Laboratory . PARTICIPANTS Normal ( N=20 ) , subjective insomnia ( N=12 ) , and objective insomnia ( N=18 ) subjects . INTERVENTIONS N/A. MEASUREMENTS AND RESULTS Lower delta and greater alpha , sigma , and beta NREM EEG activity were found in the patients with subjective insomnia but not those with objective insomnia , compared with the normal subjects . These results were robust to changes in the subtyping criteria . No effects were found for REM spectral indexes . Less delta non- REM EEG activity predicted greater deviation between subjective and PSG estimates of sleep time across all subjects . For the subjective insomnia subjects , diminished low-frequency and elevated higher frequency non- REM EEG activity was associated with 
    Output:
    
The review clearly indicates that characteristics of insomnia may not be limited to sleep .
Reports suggest that at least some individuals with insomnia may deviate from people without sleep complaints with respect to demographics , mental and physical health , childhood trauma , life events , fatigue , sleepiness , hyperarousal , hyperactivity , other sleep disorders , lifetime sleep history , chronotype , depression , anxiety , mood , quality of life , personality , happiness , worry , rumination , self-consciousness , sensitivity , dysfunctional beliefs , self-conscious emotion regulation , coping , nocturnal mentation , wake resting-state mentation , physical activity , food intake , temperature perception and hedonic evaluation .