***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: QUESTIONS UNDER STUDY In many countries newer non-benzodiazepines , zolpidem and zopiclone ( " Z-drugs " ) , are prescribed instead of benzodiazepine hypnotics . This is not supported by current evidence and guidelines . The aim of this study was to compare the perceptions of GPs on the benefits and harms of benzodiazepines and Z-drugs . METHODS A question naire was mailed to a r and om sample of 1,350 German GPs between May and June 2012 . GPs were asked to rate their perceptions on a five-point Likert scale for 12 items asked for both benzodiazepines and Z-drugs . Wilcoxon signed rank test for paired observations was used for comparison between groups . Due to multiple testing , only p values ≤0.01 were considered statistically significant . RESULTS A total of 458 question naires were returned ( response 33.9 % ) . The mean age of participants was 53.3 years ( 59.4 % males ) . GPs perceived that Z-drugs were significantly more effective in terms of reduced night-time waking , feelings of being rested on waking and improved daytime functioning than benzodiazepines ( p < 0.0001 for all comparisons ) , but not in terms of reduced time to get to sleep and increased total sleep time . All studied side effects were believed to be less often for patients receiving Z-drugs ( p < 0.0001 for all comparisons ) . A total of 73.4 % and 80.4 % answered that tolerance or withdrawal effects on stopping occur often or very often/always for benzodiazepines , whereas these values were only 30.6 % and 28.7 % for Z-drugs . CONCLUSIONS German GPs perceived that Z-drugs were more effective and safer compared to benzodiazepines , which is not supported by current evidence . The results are quite comparable to a British survey conducted seven years before Computerized symbol-digit substitution tests ( SDSTs ) and ' yes/no ' digit-symbol substitution tests ( YNDSTs ) , together with a digit-digit copying test ( DDCT ) were compared in a double-blind crossover study for hypnosedative and alcohol effects in 12 young healthy subjects . The tests were carried out before and 1 , 3.5 and 5 h after intake of 15 mg diazepam , 30 mg oxazepam , 7.5 mg zopiclone,15 mg zolpidem or 0.65 + 0.35 g/kg ethanol , these impaired performance by varying extents . The drug-induced decrements were similar in the YNDSTs and SDSTs ; the errors were subject-related and increased with alcohol intake in the YNDSTs but not in the SDSTs . Pooled baseline values in YNDSTs correlated well ( Pearson ) with those in the SDSTs . The SDSTs also correlated well with the DDCTs . The same correlations were seen when comparing absolute performances after ethanol and hypnosedatives . When using the Δ-values ( changes from baseline ) , the correlation betweenYNDSTs and SDSTs was high after placebo but low after alcohol and hypnosedatives . When using ANCOVA to measure the responses to drugs ( Δ-drug - Δ-placebo ) , the correlation between YNDSTs and SDSTs was fairly significant after most but not all active drugs . Subjective visual analogue variables did not correlate with objective performances . By comparing absolute performances with hypnosedatives we conclude that YNDSTs and SDSTs are similar , with the Δ-values indicating differences between them Abstract Rationale : The increased prevalence of sleep disturbance in old age is accompanied by a higher prescription rate of hypnotics , predominantly benzodiazepines in the elderly . In young volunteers  zopiclone exerts a beneficial effect on sleep continuity without suppression of SWS and REM sleep ; psychomotor performance and vigilance seemed to be less impaired than under classical benzoediazepines . Objective : The present study investigates the effects of zopiclone on sleep EEG and cognitive performance in comparison to temazepam and placebo in the elderly population . Methods : Single oral doses of zopiclone ( 7.5 mg ) , temazepam ( 20 mg ) and placebo were administered in a r and omized double-blind , completely counterbalanced cross-over design to 12 healthy elderly men and women ( 65.9 + 3.6 years , range 60–70 years ) . On each of the 3 study nights a sleep EEG was registered from 10 p.m. to 6.30 a.m. and cognitive performance tests were applied at 8 p.m. , 2 a.m. ( when subjects were awake for 30 min ) , 7 a.m. and 9 a.m. Results : After zopiclone treatment , sleep continuity had significantly improved and sleep stage 4 was increased compared to temazepam and placebo . In addition , both active substances significantly reduced REM density . Neither active compound substantially altered psychomotor and memory performance . Conclusions : Zopiclone and temazepam can be considered as effective hypnotics in elderly subjects when administered in that dosage . The superiority of zopiclone on sleep architecture may be related to a more specific action of zopiclone at the GABA-A benzodiazepine receptor complex . The suppression of REM density by both compounds and their subtle effects on cognition may reflect a GABAergic mediated reduction of cholinergic neurotransmission The sedative , amnestic , and performance disruptive effects of benzodiazepine ( Bz ) receptor selective and non-selective hypnotics were studied in 23 healthy , normal subjects , aged 26.8±1.0 years .  Triazolam ( 0.25 and 0.50 mg ) , zolpidem ( 10 and 20 mg ) and placebo were administered , double-blind , at bedtime in a repeated measures design . During an awakening 90 min later ( at approximate peak concentration of each drug ) a 30-min performance battery which included memory , vigilance , and psychomotor tasks was completed . Each drug and dose impaired memory ( both immediate and delayed ) , vigilance , and psychomotor performance relative to placebo . Among active drugs impairment was greatest with zolpidem 20 mg , next triazolam 0.50 mg , then zolpidem 10 mg , and finally triazolam 0.25 mg . Next morning delayed recall was also impaired by all drugs and doses ( i.e. antero grade amnesia ) . The amnestic and performance-disruptive effects paralleled the relative hypnotic effects of the drugs and doses . No receptor selectivity in these pharmacodynamic effects was observed In a double-blind , six-way crossover study the effects on psychomotor performance and memory of single doses of Ro 41 - 3696 ( 1 , 3 , 5 and 10 mg ) , a novel non-benzodiazepine partial agonist at the benzodiazepine receptor , zolpidem ( 10 mg ) and placebo were compared after night-time administration to 12 healthy young male subjects .  Psychomotor performance tests ( tracking and attention as part of a st and ardized task battery ) were conducted just before and at 1.5 and 8 h after drug intake . The memory test consisted of the recall of a list of 15 words at 8 h after drug intake which had been learned at 1.5 h after intake . At 1.5 h after drug intake 10 mg zolpidem induced markedly larger psychomotor effects than any dose of Ro 41 - 3696 . The effects of 5 and 10 mg Ro 41 - 3696 and zolpidem were significantly greater than those of placebo ( P < 0.05 ) . The following morning , 8 h after drug intake , the slight residual effects of 5 and 10 mg Ro 41 - 3696 were statistically significantly greater than placebo , whereas zolpidem effects did not differ from placebo . The results of the memory test showed that learning as well as recall were most clearly impaired by zolpidem . An influence of Ro 41 - 3696 on these variables was not observed for doses up to 5 mg . In conclusion , Ro 41 - 3696 at all doses tested induced less effects on psychomotor performance and memory than 10 mg zolpidem at 1.5 h after intake . However , the effects of Ro 41 - 3696 appeared to be of longer duration STUDY OBJECTIVES To evaluate the next-morning residual effects of ramelteon ( 8 mg ) , zopiclone ( 7.5 mg ) , and placebo on driving performance , memory functioning , psychomotor performance , and mood in healthy adult subjects following bedtime dosing and a middle of the night awakening . DESIGN Single-center , r and omized , double-blind , double-dummy , placebo-controlled , crossover study . SETTING Utrecht University , The Netherl and s. PARTICIPANTS 30 healthy volunteers ( 15 males and 15 females ) . INTERVENTIONS a single dose of ramelteon ( 8 mg ) , zopiclone ( 7.5 mg ) , and placebo , administered at bedtime . MEASUREMENTS A balance test was performed at night . Other tests were performed the following morning , 8.5 h after administration . Subjects performed a 100-km highway driving test in normal traffic . Primary outcome measure was the st and ard deviation of the lateral position ( SDLP ) , i.e. , the weaving of the car . After driving , cognitive , memory , and psychomotor tests were performed and mood was assessed . RESULTS SDLP was significantly increased after the intake of ramelteon ( + 2.2 cm ) and zopiclone ( + 2.9 cm ) . Ramelteon and zopiclone produced significant impairment on reaction time ( P<0.024 ) in the Sternberg Memory Scanning Test , slow ( P<0.007 ) and fast ( P<0.010 ) tracking , reaction speed ( P<0.015 ) and tracking ( P<0.001 ) in the Divided Attention Test , and delayed recall ( P<0.032 ) in the Word Learning Test . In contrast to ramelteon , zopiclone additionally impaired performance on the Digit Symbol Substitution Test ( P<0.001 ) and the balance test ( P<0.001 ) . CONCLUSIONS Ramelteon ( 8 mg ) and zopiclone ( 7.5 mg ) significantly impaired driving performance , cognitive , memory , and psychomotor performance the morning following bedtime administration . In contrast to zopiclone , ramelteon produced no balance impairments . CLINICAL TRIAL IDENTIFIER : NCT00319215 ( www . clinical trials.gov ) STUDY OBJECTIVES To compare residual effects of zaleplon 10 mg , zopiclone 7.5 mg , and placebo , and a social dose of alcohol on  car driving , memory , and psychomotor performance . DESIGN Two-part placebo controlled , crossover study . Part 1 was single blind , Part 2 double blind . SETTING University research institute . PARTICIPANTS Thirty healthy volunteers ( 15 men and 15 women , mean age 32 + /- 7 years ) INTERVENTIONS In Part 1 alcohol and alcohol-placebo drinks were administered around noon . In Part 2 single oral doses of zaleplon 10 mg , zopiclone 7.5 mg and placebo were administered at bedtime . MEASUREMENT AND RESULTS A highway driving test , laboratory tests of word learning , critical tracking and divided attention , and subjective assessment s of sleep , mood , and effects of treatments on driving . Driving started 40 minutes after a second alcohol dose in Part 1 , and 10 hours after drug intake in Part 2 . The results demonstrated that alcohol , at average plasma concentrations of approximately 0.030 g/dl , significantly impaired performance in all tests . Zaleplon 's  residual effects did not differ significantly from those of placebo in any test . In contrast , zopiclone had significant residual effects on driving , divided attention , and memory . The magnitude of impairment in the driving test observed the morning after zopiclone 7.5 mg was twice that observed with alcohol . CONCLUSION Zaleplon 10 mg has no residual effects on driving when taken at bedtime , 10 hours before driving . In contrast , zopiclone 7.5 mg can cause marked residual impairment . Patients should be advised to avoid driving the morning after zopiclone administration AIMS To compare the duration of the residual hypnotic and sedative effects of zaleplon with those of zolpidem and placebo following nocturnal administration at various times before morning awakening . METHODS Zaleplon 10 mg , zolpidem 10 mg , or placebo was administered double-blind to 36 healthy subjects under st and ardized conditions in a six-period , incomplete-block , crossover study . Subjects were gently awakened and given medication at predetermined times 5 , 4 , 3 , or 2 h before morning awakening , which occurred 8 h after bedtime . When the subjects awoke in the morning , a battery of subjective and objective assessment s of residual effects of hypnotics was administered . RESULTS No residual effects were demonstrated after zaleplon 10 mg , when administered as little as 2 h before waking , on either subjective or objective assessment s , 
    Output:
    
An additional medium effect size was observed for zolpidem  on attention .
It is clear from these data that the use of a single dose of the z-drugs in healthy adults as measured in the morning following the exposure does produce a specific rather than a generalized negative effect on cognitive function .