human
***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: The effectiveness of light therapy in seasonal affective disorder ( SAD ) was evaluated in 105 subjects across five centers . Three intensities of light ( 60 lux , 600 lux , and 3500 lux ) were used in a 2-week r and omized , parallel design . There was no significant difference in antidepressant efficacy of the three intensities of light . All three intensities produced a similar frequency of antidepressant response to each other and to that reported in previous studies . There were site differences in the severity of depression during light treatment , but diagnosis and medication status did not affect antidepressant response . These findings suggest that light therapy has an antidepressant action by a nonspecific effect or that light is biologically active in the treatment of SAD across a wide range of intensities Fifty-five patients with winter seasonal affective disorder ( SAD ) were treated with a light visor , a newly developed portable light-delivery system , in a controlled parallel design . A dim ( 400 lux ) visor was compared with a bright ( 6000 lux ) visor for either 30 or 60 minutes in the morning for 1 week . Response rates for these two treatments were 36 % and 56 % , respectively ; the duration of treatment sessions did not affect outcome . There was no evidence that the brighter visor was superior in efficacy to the dimmer one . Significantly greater relapse occurred following withdrawal of the dimmer visor . Alterative explanations for these findings are that the light visor is acting as a placebo or that it is equally effective over a wide range of intensities Background There are controversies about the most effective treatment to eradicate first growth of Pseudomonas aeruginosa ( P aeruginosa ) from the lower airways of patients with cystic fibrosis ( CF ) . UK guidelines recommend oral treatment , but some advocate intravenous ( IV ) treatment . The objective of this study was to assess the feasibility of conducting a r and omised controlled trial comparing two treatment strategies to eradicate P aeruginosa in CF patients . Methods /Principal Findings Two surveys were conducted . Survey [ 1 ] included clinicians who were responsible for the treatment of individuals with CF , to assess their clinical practice , opinions  and  numbers of potentially eligible patients . Survey [ 2 ] included adults and young people aged 13 years or more with CF and parents of children with CF aged less than 13 years , identified at six UK CF centres , who fulfilled eligibility criteria for the proposed clinical trial , to assess their views about the interventions and their willingness to participate in the trial . Generally clinicians treat first or new growth of P aeruginosa with oral antibiotics , but 90 % reported that they would consider IV treatment of first isolation of P aeruginosa . 74 % of clinicians would consider recruiting their patients and 45 % of consumers would consider entry for themselves or their children into a trial comparing oral with intravenous antibiotics . The median rate per annum for first or new growths of P aeruginosa in adults was 3 % ( range 1 % to 9 % ) and in children was 10 % ( range 3 % to 23 % ) . If the trial was conducted across the UK , with a consent rate of 45 % , then the number of eligible patients per annum who would be willing to take part in a study would be approximately 41 adults and 203 children . Conclusions This work demonstrates the importance of feasibility studies in preparation for multicentre clinical trials . It confirmed the uncertainty amongst clinicians and patients about the clinical question , enabled assessment of the number of potentially eligible patients , the proportion of patients and clinicians prepared to participate and aspects of trial design which might encourage this . It showed that a clinical trial was feasible , but only if patients were recruited from across United Kingdom In patients with winter seasonal affective disorder ( SAD ) the onset of a depressive episode is probably associated with the decreasing amount of light during the autumn . A highly predictable onset of a recurrent depressive episode with seasonal pattern provides a rationale for testing the efficacy of bright-light treatment as a preventive measure . Twelve out- patients with winter SAD were assigned to start bright light treatment either when they were well , or not to start it until the first symptoms of depression had already emerged . The severity of depressive symptoms was prospect ively rated for a parallel r and omized comparison . Bright light given well in advance of the emerging symptoms prevented a depressive episode . Clinical remission was significantly more frequent in the former subgroup of the patients in January and in March . To sum up , bright light can be successfully administered as prophylactic treatment for the prevention of winter SAD The objectives of this prospect i ve study were to investigate the influence of comorbid disorders and that of continuation light treatment on remission rates and on a subsequent onset of a depressive episode in out patients ( n = 20 ) with winter depression . The effects of light treatment were evaluated by the structured clinical interviews and by the self-ratings of mood scored monthly for a follow-up period of 1 year . The remission rates of the patients ( n = 8) who proceeded light treatment until the late winter were not significantly different from those of the patients ( n = 6 ) who stopped treatment early during the winter . A more extensive variation in the rates during the year was observed in the former group of patients among whom the comorbid avoidant personality was more frequent , indicating an increased risk of an earlier onset of a depressive episode Of 39 diagnosed Seasonal Affective Disorder ( SAD ) patients who were interviewed 2 - 5 years after participation in a light therapy trial , 10 continued to have recurrent  major depressive episodes  in winter , and 17 manifested sub-syndromal SAD ( 2 patients also had recurrent brief depression , seasonal type ) . 8 patients had recovered , and 4 had shifted in symptomatology . Thus , over a number of years , the clinical diagnosis changed for the better in 64 % of the patients , suggesting that SAD is not a prodromal form of a more chronic major affective disorder , and that light therapy ( and perhaps also light-oriented behaviour ) reduced the incidence and depth of subsequent depressive episodes . Further evidence for this was the large reduction in use of conventional antidepressant drugs ( from 17 to 1 ) during the follow-up period . Diagnosis of SAD was stable and reliable Seasonal affective disorder ( SAD ) is a syndrome characterized by recurrent depressions that occur annually at the same time each year . We describe 29 patients with SAD ; most of them had a bipolar affective disorder , especially bipolar II , and their depressions were generally characterized by hypersomnia , overeating , and carbohydrate craving and seemed to respond to changes in climate and latitude . Sleep recordings in nine depressed patients confirmed the presence of hypersomnia and showed increased sleep latency and reduced slow-wave ( delta ) sleep . Preliminary studies in 11 patients suggest that extending the photoperiod with bright artificial light has an antidepressant effect Background Seasonal affective disorder ( SAD ) is a subtype of recurrent depression involving major depressive episodes during the fall and /or winter months that remit in the spring . The central public health challenge in the management of SAD is prevention of winter depression recurrence .  Light therapy ( LT ) is the established and best available acute SAD treatment . However , long-term compliance with daily LT from first symptom through spontaneous springtime remission every fall/winter season is poor . Time-limited alternative treatments with effects that endure beyond the cessation of acute treatment are needed to prevent the annual recurrence of SAD . Methods / design This is an NIMH-funded R01-level r and omized clinical trial to test the efficacy of a novel , SAD-tailored cognitive-behavioral group therapy ( CBT ) against LT in a head-to-head comparison on next winter outcomes . This project is design ed to test for a clinical ly meaningful difference between  CBT and LT on depression recurrence in the next winter ( the primary outcome ) . This is a concurrent two-arm study that will r and omize 160 currently symptomatic community adults with major depression , recurrent with seasonal pattern , to CBT or LT .  After 6 weeks of treatment in the initial winter , participants are followed in the subsequent summer , the next winter , and two winters later . Key method ological issues surround timing study procedures for a predictably recurrent and time-limited disorder with a focus on long-term outcomes . Discussion The chosen design answers the primary question of whether prior exposure to CBT is associated with a substantially lower likelihood of depression recurrence the next winter than LT . This design does not test the relative contributions of the cognitive-behavioral treatment components vs. nonspecific factors to CBT ’s outcomes and is not adequately powered to test for differences or equivalence between cells at treatment endpoint . Alternative design s addressing these limitations would have required more patients , increased costs , and reduced power to detect a difference in the primary outcome .Trial registration Clinical trials.gov identifier Seasonal affective disorder ( SAD ) , winter type , is characterized by the occurrence of depression in autumn/winter , followed by a complete recovery in spring/summer . In SAD patients , some atyp- ical symptoms are highly characteristic , such as hypersomnia , carbohydrate craving , weight gain , fatigue , and loss of social inter- actions ( Rosenthal et ai 1984 ) . The repeated occurrence of symp- toms during successive winters is one of the diagnostic criteria , l ~ lot every SAD patient becomes depressed every year , however . In prospect i ve studies it was found that 70,4 % of the SAD diagnosed subjects who were followed from a symptom-free moment at the end of September , became depressed during the following winter ( Meesters et al 1991 ; 1993a ) , In a previous study it was found that severe winter depression can be prevented by light treatment administered at the first signs of an emerging winter depression , that is , the moment subjects reported complaints of slight depression ( Meesters et al 1991 ; 1993a ) . In the present study , the question was raised whether light exposure given at the beginning of the winter season , when sub- jeers are still free of symptoms , could be successful in preventing the development of a winter depressmn during the rest of the season . Such a ueatment , which might prevent depression alto- gether , would be highly advantageous BACKGROUND The suppression of melatonin by light at 00.30 hours has been shown to be greater in winter than in summer on patients with seasonal affective disorder ( SAD ) but not in matched normal controls . METHOD In this study 12 patients with SAD and 12 matched normal controls were exposed to morning light therapy in the winter .  Melatonin profiles and sensitivity to light were measured before and after treatment . RESULTS The SAD but not the normal group showed a phase advance of melatonin rhythms in response to phototherapy . There was an association between phase position and phase shift in the SAD but not in the normal group . CONCLUSIONS There may be instability of circadian rhythms in SAD mediated by a high-amplitude phase response curve , rather than a fixed phase abnormality as had been previously suggested . This instability may be secondary to impaired serotoninergic function in the afferent pathways to the suprachiasmatic nuclei OBJECTIVE Light therapy and antidepressants have shown comparable efficacy in separate studies of seasonal affective disorder treatment , but few studies have directly compared the two treatments . This study compared the effectiveness of light therapy and an antidepressant within a single trial . METHOD This double-blind , r and omized , controlled trial was conducted in four Canadian centers over three winter seasons . Patients met DSM-IV criteria for major depressive disorder with a seasonal ( winter ) pattern and had scores > or = 23 on the 24-item Hamilton Depression Rating Scale . After a baseline observation week , eligible patients were r and omly assigned to 8 weeks of double-blind treatment with either 1 ) 10,000-lux light treatment and a placebo capsule , or 2 ) 100-lux light treatment ( placebo light ) and fluoxetine , 20 mg/day . Light treatment was applied for 30 minutes/day in the morning with a fluorescent white-light box ; placebo light boxes used neutral density filters . RESULTS A total of 96 patients were r and omly assigned to a treatment condition . Intent-to-treat analysis showed overall improvement with time , with no differences between treatments . There were also no differences between the light and fluoxetine treatment groups in clinical response rates ( 67 % for each group ) or remission rates ( 50 % and 54 % , respectively ) . Post hoc testing found that light-treated patients had greater improvement at 1 week but not at other time points . Fluoxetine was associated with greater treatment-emergent adverse events ( agitation , sleep disturbance , palpitations ) , but both treatments were generally well-tolerated with no differences in overall number of adverse effects . CONCLUSIONS Light treatment showed earlier response onset and lower rate of some adverse events relative to fluoxetine , but there were no other significant differences in outcome between light therapy and antidepressant medication . Although limited by lack of a double-placebo condition , this study supports the effectiveness and tolerability of both treatments for seasonal affective disorder and suggests that other clinical factors , including patient preference , should guide selection of first-line treatment Background  Depression  frequently occurs in the elderly and in patients suffering from dementia . Its cause is largely unknown , but several studies point to a possible contribution of circadian rhythm disturbances . Post-mortem studies on aging , dementia and depression show impaired functioning of the suprachiasmatic nucleus ( SCN ) which is thought to be involved in the increased prevalence of day-night rhythm perturbations in these conditions . Bright light enhances neuronal activity in the SCN . Bright light therapy has beneficial effects on rhythms and mood in institutionalized moderate to advanced demented elderly . In spite of the fact that this is a potentially safe and inexpensive treatment option , no previous clinical trial evaluated the use of long-term daily light therapy to prevent worsening of sleep-wake rhythms and depressive symptoms in early to moderately demented home-dwelling elderly . Methods / Design This study investigates whether 
    Output:
    
agent
Overall , both forms of preventive light therapy reduced the incidence of SAD numerically compared with no light therapy .
***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: The effectiveness of light therapy in seasonal affective disorder ( SAD ) was evaluated in 105 subjects across five centers . Three intensities of light ( 60 lux , 600 lux , and 3500 lux ) were used in a 2-week r and omized , parallel design . There was no significant difference in antidepressant efficacy of the three intensities of light . All three intensities produced a similar frequency of antidepressant response to each other and to that reported in previous studies . There were site differences in the severity of depression during light treatment , but diagnosis and medication status did not affect antidepressant response . These findings suggest that light therapy has an antidepressant action by a nonspecific effect or that light is biologically active in the treatment of SAD across a wide range of intensities Fifty-five patients with winter seasonal affective disorder ( SAD ) were treated with a light visor , a newly developed portable light-delivery system , in a controlled parallel design . A dim ( 400 lux ) visor was compared with a bright ( 6000 lux ) visor for either 30 or 60 minutes in the morning for 1 week . Response rates for these two treatments were 36 % and 56 % , respectively ; the duration of treatment sessions did not affect outcome . There was no evidence that the brighter visor was superior in efficacy to the dimmer one . Significantly greater relapse occurred following withdrawal of the dimmer visor . Alterative explanations for these findings are that the light visor is acting as a placebo or that it is equally effective over a wide range of intensities Background There are controversies about the most effective treatment to eradicate first growth of Pseudomonas aeruginosa ( P aeruginosa ) from the lower airways of patients with cystic fibrosis ( CF ) . UK guidelines recommend oral treatment , but some advocate intravenous ( IV ) treatment . The objective of this study was to assess the feasibility of conducting a r and omised controlled trial comparing two treatment strategies to eradicate P aeruginosa in CF patients . Methods /Principal Findings Two surveys were conducted . Survey [ 1 ] included clinicians who were responsible for the treatment of individuals with CF , to assess their clinical practice , opinions  and  numbers of potentially eligible patients . Survey [ 2 ] included adults and young people aged 13 years or more with CF and parents of children with CF aged less than 13 years , identified at six UK CF centres , who fulfilled eligibility criteria for the proposed clinical trial , to assess their views about the interventions and their willingness to participate in the trial . Generally clinicians treat first or new growth of P aeruginosa with oral antibiotics , but 90 % reported that they would consider IV treatment of first isolation of P aeruginosa . 74 % of clinicians would consider recruiting their patients and 45 % of consumers would consider entry for themselves or their children into a trial comparing oral with intravenous antibiotics . The median rate per annum for first or new growths of P aeruginosa in adults was 3 % ( range 1 % to 9 % ) and in children was 10 % ( range 3 % to 23 % ) . If the trial was conducted across the UK , with a consent rate of 45 % , then the number of eligible patients per annum who would be willing to take part in a study would be approximately 41 adults and 203 children . Conclusions This work demonstrates the importance of feasibility studies in preparation for multicentre clinical trials . It confirmed the uncertainty amongst clinicians and patients about the clinical question , enabled assessment of the number of potentially eligible patients , the proportion of patients and clinicians prepared to participate and aspects of trial design which might encourage this . It showed that a clinical trial was feasible , but only if patients were recruited from across United Kingdom In patients with winter seasonal affective disorder ( SAD ) the onset of a depressive episode is probably associated with the decreasing amount of light during the autumn . A highly predictable onset of a recurrent depressive episode with seasonal pattern provides a rationale for testing the efficacy of bright-light treatment as a preventive measure . Twelve out- patients with winter SAD were assigned to start bright light treatment either when they were well , or not to start it until the first symptoms of depression had already emerged . The severity of depressive symptoms was prospect ively rated for a parallel r and omized comparison . Bright light given well in advance of the emerging symptoms prevented a depressive episode . Clinical remission was significantly more frequent in the former subgroup of the patients in January and in March . To sum up , bright light can be successfully administered as prophylactic treatment for the prevention of winter SAD The objectives of this prospect i ve study were to investigate the influence of comorbid disorders and that of continuation light treatment on remission rates and on a subsequent onset of a depressive episode in out patients ( n = 20 ) with winter depression . The effects of light treatment were evaluated by the structured clinical interviews and by the self-ratings of mood scored monthly for a follow-up period of 1 year . The remission rates of the patients ( n = 8) who proceeded light treatment until the late winter were not significantly different from those of the patients ( n = 6 ) who stopped treatment early during the winter . A more extensive variation in the rates during the year was observed in the former group of patients among whom the comorbid avoidant personality was more frequent , indicating an increased risk of an earlier onset of a depressive episode Of 39 diagnosed Seasonal Affective Disorder ( SAD ) patients who were interviewed 2 - 5 years after participation in a light therapy trial , 10 continued to have recurrent  major depressive episodes  in winter , and 17 manifested sub-syndromal SAD ( 2 patients also had recurrent brief depression , seasonal type ) . 8 patients had recovered , and 4 had shifted in symptomatology . Thus , over a number of years , the clinical diagnosis changed for the better in 64 % of the patients , suggesting that SAD is not a prodromal form of a more chronic major affective disorder , and that light therapy ( and perhaps also light-oriented behaviour ) reduced the incidence and depth of subsequent depressive episodes . Further evidence for this was the large reduction in use of conventional antidepressant drugs ( from 17 to 1 ) during the follow-up period . Diagnosis of SAD was stable and reliable Seasonal affective disorder ( SAD ) is a syndrome characterized by recurrent depressions that occur annually at the same time each year . We describe 29 patients with SAD ; most of them had a bipolar affective disorder , especially bipolar II , and their depressions were generally characterized by hypersomnia , overeating , and carbohydrate craving and seemed to respond to changes in climate and latitude . Sleep recordings in nine depressed patients confirmed the presence of hypersomnia and showed increased sleep latency and reduced slow-wave ( delta ) sleep . Preliminary studies in 11 patients suggest that extending the photoperiod with bright artificial light has an antidepressant effect Background Seasonal affective disorder ( SAD ) is a subtype of recurrent depression involving major depressive episodes during the fall and /or winter months that remit in the spring . The central public health challenge in the management of SAD is prevention of winter depression recurrence .  Light therapy ( LT ) is the established and best available acute SAD treatment . However , long-term compliance with daily LT from first symptom through spontaneous springtime remission every fall/winter season is poor . Time-limited alternative treatments with effects that endure beyond the cessation of acute treatment are needed to prevent the annual recurrence of SAD . Methods / design This is an NIMH-funded R01-level r and omized clinical trial to test the efficacy of a novel , SAD-tailored cognitive-behavioral group therapy ( CBT ) against LT in a head-to-head comparison on next winter outcomes . This project is design ed to test for a clinical ly meaningful difference between  CBT and LT on depression recurrence in the next winter ( the primary outcome ) . This is a concurrent two-arm study that will r and omize 160 currently symptomatic community adults with major depression , recurrent with seasonal pattern , to CBT or LT .  After 6 weeks of treatment in the initial winter , participants are followed in the subsequent summer , the next winter , and two winters later . Key method ological issues surround timing study procedures for a predictably recurrent and time-limited disorder with a focus on long-term outcomes . Discussion The chosen design answers the primary question of whether prior exposure to CBT is associated with a substantially lower likelihood of depression recurrence the next winter than LT . This design does not test the relative contributions of the cognitive-behavioral treatment components vs. nonspecific factors to CBT ’s outcomes and is not adequately powered to test for differences or equivalence between cells at treatment endpoint . Alternative design s addressing these limitations would have required more patients , increased costs , and reduced power to detect a difference in the primary outcome .Trial registration Clinical trials.gov identifier Seasonal affective disorder ( SAD ) , winter type , is characterized by the occurrence of depression in autumn/winter , followed by a complete recovery in spring/summer . In SAD patients , some atyp- ical symptoms are highly characteristic , such as hypersomnia , carbohydrate craving , weight gain , fatigue , and loss of social inter- actions ( Rosenthal et ai 1984 ) . The repeated occurrence of symp- toms during successive winters is one of the diagnostic criteria , l ~ lot every SAD patient becomes depressed every year , however . In prospect i ve studies it was found that 70,4 % of the SAD diagnosed subjects who were followed from a symptom-free moment at the end of September , became depressed during the following winter ( Meesters et al 1991 ; 1993a ) , In a previous study it was found that severe winter depression can be prevented by light treatment administered at the first signs of an emerging winter depression , that is , the moment subjects reported complaints of slight depression ( Meesters et al 1991 ; 1993a ) . In the present study , the question was raised whether light exposure given at the beginning of the winter season , when sub- jeers are still free of symptoms , could be successful in preventing the development of a winter depressmn during the rest of the season . Such a ueatment , which might prevent depression alto- gether , would be highly advantageous BACKGROUND The suppression of melatonin by light at 00.30 hours has been shown to be greater in winter than in summer on patients with seasonal affective disorder ( SAD ) but not in matched normal controls . METHOD In this study 12 patients with SAD and 12 matched normal controls were exposed to morning light therapy in the winter .  Melatonin profiles and sensitivity to light were measured before and after treatment . RESULTS The SAD but not the normal group showed a phase advance of melatonin rhythms in response to phototherapy . There was an association between phase position and phase shift in the SAD but not in the normal group . CONCLUSIONS There may be instability of circadian rhythms in SAD mediated by a high-amplitude phase response curve , rather than a fixed phase abnormality as had been previously suggested . This instability may be secondary to impaired serotoninergic function in the afferent pathways to the suprachiasmatic nuclei OBJECTIVE Light therapy and antidepressants have shown comparable efficacy in separate studies of seasonal affective disorder treatment , but few studies have directly compared the two treatments . This study compared the effectiveness of light therapy and an antidepressant within a single trial . METHOD This double-blind , r and omized , controlled trial was conducted in four Canadian centers over three winter seasons . Patients met DSM-IV criteria for major depressive disorder with a seasonal ( winter ) pattern and had scores > or = 23 on the 24-item Hamilton Depression Rating Scale . After a baseline observation week , eligible patients were r and omly assigned to 8 weeks of double-blind treatment with either 1 ) 10,000-lux light treatment and a placebo capsule , or 2 ) 100-lux light treatment ( placebo light ) and fluoxetine , 20 mg/day . Light treatment was applied for 30 minutes/day in the morning with a fluorescent white-light box ; placebo light boxes used neutral density filters . RESULTS A total of 96 patients were r and omly assigned to a treatment condition . Intent-to-treat analysis showed overall improvement with time , with no differences between treatments . There were also no differences between the light and fluoxetine treatment groups in clinical response rates ( 67 % for each group ) or remission rates ( 50 % and 54 % , respectively ) . Post hoc testing found that light-treated patients had greater improvement at 1 week but not at other time points . Fluoxetine was associated with greater treatment-emergent adverse events ( agitation , sleep disturbance , palpitations ) , but both treatments were generally well-tolerated with no differences in overall number of adverse effects . CONCLUSIONS Light treatment showed earlier response onset and lower rate of some adverse events relative to fluoxetine , but there were no other significant differences in outcome between light therapy and antidepressant medication . Although limited by lack of a double-placebo condition , this study supports the effectiveness and tolerability of both treatments for seasonal affective disorder and suggests that other clinical factors , including patient preference , should guide selection of first-line treatment Background  Depression  frequently occurs in the elderly and in patients suffering from dementia . Its cause is largely unknown , but several studies point to a possible contribution of circadian rhythm disturbances . Post-mortem studies on aging , dementia and depression show impaired functioning of the suprachiasmatic nucleus ( SCN ) which is thought to be involved in the increased prevalence of day-night rhythm perturbations in these conditions . Bright light enhances neuronal activity in the SCN . Bright light therapy has beneficial effects on rhythms and mood in institutionalized moderate to advanced demented elderly . In spite of the fact that this is a potentially safe and inexpensive treatment option , no previous clinical trial evaluated the use of long-term daily light therapy to prevent worsening of sleep-wake rhythms and depressive symptoms in early to moderately demented home-dwelling elderly . Methods / Design This study investigates whether 
    Output:
    