***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 psychological treatments for PTSD is likely to be enhanced by improved underst and ing of the factors involved in maintaining the disorder . Ehlers and Clark [ A cognitive model of persistent posttraumatic stem disorder Behav . Res . Ther . 38 ( 2000 ) 319 - 345 ] recently proposed a cognitive model of maintenance . The current study aim ed to investigate several cognitive factors highlighted in Ehlers and Clark 's model using a prospect i ve design . Fifty-seven victims of physical or sexual assault participated in the study . Cognitive factors were assessed within 4 months of assault and victims were followed-up 6 and 9 months after the assault . Cognitive variables which significantly predicted PTSD severity at both follow-ups were : cognitive processing style during assault ( mental defeat , mental confusion , detachment ) ; appraisal of assault sequelae ( appraisal of symptoms , perceived negative responses of others , permanent change ) ; negative beliefs about self and world ; and maladaptive control strategies ( avoidance/safety seeking ) . Relationships between early appraisal s , control strategies , and processing styles and subsequent PTSD severity remained significant after statistically controlling for gender and perceived assault severity . These findings support the cognitive model of PTSD proposed by Ehlers and Clark and suggest that effective treatment will need to address these cognitive factors Acute stress disorder ( ASD ) is a precursor of chronic posttraumatic stress disorder ( PTSD ) . Twenty-four participants with ASD following civilian trauma were given 5 sessions of either cognitive-behavioral therapy ( CBT ) or supportive counseling ( SC ) within 2 weeks of their trauma . Fewer participants in CBT ( 8 % ) than in SC ( 83 % ) met criteria for PTSD at posttreatment . There were also fewer cases of PTSD in the CBT condition ( 17 % ) than in the SC condition ( 67 % ) 6 months posttrauma . There were greater statistically and clinical ly significant reductions in intrusive , avoidance , and depressive symptomatology among the CBT participants than among the SC participants . This study represents the 1st demonstration of successful treatment of ASD with CBT and its efficacy in preventing chronic PTSD OBJECTIVE The purpose of this study was to prospect ively evaluate the onset , overlap , and course of posttraumatic stress disorder ( PTSD ) and major depression following traumatic events . METHOD The occurrence of PTSD and major depression and the intensity of related symptoms were assessed in 211 trauma survivors recruited from a general hospital 's emergency room .  Psychometrics and structured clinical interview ( the Structured Clinical Interview for DSM-III-R and the Clinician-Administered PTSD Scale ) were administered 1 week , 1 month , and 4 months after the traumatic event .  Heart rate  was assessed upon arrival at the emergency room for subjects with physical injury . Twenty-three subjects with PTSD and 35 matched comparison subjects were followed for 1 year . RESULTS Major depression and PTSD occurred early on after trauma ; patients with these diagnoses had similar recovery rates : 63 survivors ( 29.9 % ) met criteria for PTSD at 1 month , and 37 ( 17.5 % ) had PTSD at 4 months . Forty subjects ( 19.0 % ) met criteria for major depression at 1 month , and 30 ( 14.2 % ) had major depression at 4 months . Comorbid depression occurred in 44.5 % of PTSD patients at 1 month and in 43.2 % at 4 months . Comorbidity was associated with greater symptom severity and lower levels of functioning . Survivors with PTSD had higher heart rate levels at the emergency room and reported more intrusive symptoms , exaggerated startle , and peritraumatic dissociation than those with major depression . Prior depression was associated with a higher prevalence of major depression and with more reported symptoms . CONCLUSIONS Major depression and PTSD are independent sequelae of traumatic events , have similar prognoses , and interact to increase distress and dysfunction . Both should be targeted by early treatment interventions and by neurobiological research This report examines initial distress levels , course of symptoms , incidence of posttraumatic stress disorder ( PTSD ) , predictors of short-term outcome , and value of prophylactic counseling in a consecutive series of 40 ambulant trauma clinic attenders with minor road traffic accident ( RTA ) injuries . Subjects were r and omly allocated to intervention and monitoring groups following assessment at a mean of 7 days posttrauma and reassessed at 3 months using a variety of st and ard rating scales . Seventy-five percent reported significant levels of distress at 1 week posttrauma . By 3 months this had decreased sharply to 35 % , and 22 % were significantly impaired by clinical assessment . Incidence of PTSD over 3 months was estimated at 19 % and point prevalence at 3 months posttrauma was 9 % . High initial distress , increasing age , and high levels of perceived threat were significant independent predictors of morbidity , and no significant differences in outcome were found between intervention and monitoring groups at 3 months Two studies of assault victims examined the roles of ( a ) disorganized trauma memories in the development of posttraumatic stress disorder ( PTSD ) , ( b ) peritraumatic cognitive processing in the development of problematic memories and PTSD , and ( c ) ongoing dissociation and negative appraisal s of memories in maintaining symptomatology . In the cross-sectional study ( n = 81 ) , comparisons of current , past , and no-PTSD groups suggested that peritraumatic cognitive processing is related to the development of disorganized memories and PTSD . Ongoing dissociation and negative appraisal s served to maintain PTSD symptoms . The prospect i ve study ( n = 73 ) replicated these findings longitudinally .  Cognitive and memory assessment s completed within 12-weeks postassault predicted 6-month symptoms . Assault severity measures explained 22 % of symptom variance ; measures of cognitive processing , memory disorganization , and appraisal s increased prediction accuracy to 71 % A prospect i ve longitudinal study assessed 967 consecutive patients who attended an emergency clinic shortly after a motor vehicle accident , again at 3 months , and at 1 year . The prevalence of posttraumatic stress disorder ( PTSD ) was 23.1 % at 3 months and 16.5 % at 1 year . Chronic PTSD was related to some objective measures of trauma severity , perceived threat , and dissociation during the accident , to female gender , to previous emotional problems , and to litigation . Maintaining psychological factors , that is , negative interpretation of intrusions , rumination , thought suppression , and anger cognitions , enhanced the accuracy of the prediction . Negative interpretation of intrusions , persistent medical problems , and rumination at 3 months were the most important predictors of PTSD symptoms at 1 year . Rumination , anger cognitions , injury severity , and prior emotional problems identified cases of delayed onset BACKGROUND Dissociative symptoms during trauma predict post-traumatic stress disorder ( PTSD ) , but they are often transient . It is controversial whether they predict chronic PTSD over and above what can be predicted from other post-trauma symptoms . AIMS To investigate prospect ively the relationship between dissociative symptoms before , during and after a trauma and other psychological predictors , and chronic PTSD . METHOD Two sample s of 27 and 176 road traffic accident survivors were recruited . Patients were assessed shortly after the accident and followed at intervals over the next 6 months . Assessment s included  measures of dissociation , memory fragmentation , data -driven processing , rumination and PTSD symptoms .  RESULTS All measures of dissociation , particularly persistent dissociation 4 weeks after the accident , predicted chronic PTSD severity at 6 months . Dissociative symptoms predicted subsequent PTSD over and above the other PTSD symptom clusters . Memory fragmentation and data -driven processing also predicted PTSD . Rumination about the accident was among the strongest predictors of subsequent PTSD symptoms . CONCLUSIONS Persistent dissociation and rumination 4 weeks after trauma are more useful in identifying those patients who are likely to develop  chronic PTSD  than initial reactions BACKGROUND Psychological debriefing is widely used for trauma victims but there is uncertainty about its efficacy . We have previously reported a r and omised controlled trial which concluded that at 4 months it was ineffective . AIMS To evaluate the 3-year outcome in a r and omised controlled trial of debriefing for consecutive subjects admitted to hospital following a road traffic accident . METHOD Patients were assessed in hospital by the Impact of Event Scale ( IES ) , Brief Symptom Inventory ( BSI ) and question naire and re-assessed at 3 months and 3 years . The intervention was psychological debriefing as recommended and described in the literature . RESULTS The intervention group had a significantly worse outcome at 3 years in terms of general psychiatric symptoms ( BSI ) , travel anxiety when being a passenger , pain , physical problems , overall level of functioning , and financial problems . Patients who initially had high intrusion and avoidance symptoms ( IES ) remained symptomatic if they had received the intervention , but recovered if they did not receive the intervention . CONCLUSIONS Psychological debriefing is ineffective and has adverse long-term effects . It is not an appropriate treatment for trauma victims This research represents the first controlled treatment study of hypnosis and cognitive- behavioral therapy ( CBT ) of acute stress disorder ( ASD ) . Civilian trauma survivors ( N=87 ) who met criteria for ASD were r and omly allocated to 6 sessions of CBT , CBT combined with hypnosis ( CBT-hypnosis ) , or supportive counseling ( SC ) . CBT comprised exposure , cognitive restructuring , and anxiety management . CBT-hypnosis comprised the CBT components with each imaginal exposure preceded by a hypnotic induction and suggestions to engage fully in the exposure . In terms of treatment completers ( n=69 ) , fewer participants in the CBT and CBT-hypnosis groups met criteria for posttraumatic stress disorder at posttreatment and 6-month follow-up than those in the SC group . CBT-hypnosis result ed in greater reduction in reexperiencing symptoms at posttreatment than CBT . These findings suggest that hypnosis may have use in facilitating the treatment effects of CBT for posttraumatic stress BACKGROUND It is unclear what psychological help should be offered in the aftermath of traumatic events . Similarly , there is a lack of clarity about the best way of identifying people who are unlikely to recover from early posttraumatic symptoms without intervention . OBJECTIVE To determine whether cognitive therapy or a self-help booklet given in the initial months after a traumatic event is more effective in preventing chronic posttraumatic stress disorder ( PTSD ) than repeated assessment s. DESIGN R and omized controlled trial . Patients Motor vehicle accident survivors ( n = 97 ) who had PTSD in the initial months after the accident and met symptom criteria that had predicted persistent PTSD in a large naturalistic prospect i ve study of a comparable population . SETTING Patients were recruited from attendees at local accident and emergency departments . INTERVENTIONS Patients completed a 3-week self-monitoring phase . Those who did not recover with self-monitoring ( n = 85 ) were r and omly assigned to receive cognitive therapy ( n = 28 ) , a self-help booklet based on principles of cognitive behavioral therapy ( n = 28 ) , or repeated assessment s ( n = 29 ) . MAIN OUTCOME MEASURES Symptoms of PTSD as assessed by self-report and independent assessors unaware of the patient 's allocation . Main assessment s were at 3 months ( posttreatment , n = 80 ) and 9 months ( follow-up , n = 79 ) . RESULTS Twelve percent ( n = 12 ) of patients recovered with self-monitoring .  Cognitive therapy was more effective in reducing symptoms of PTSD , depression , anxiety , and disability than the self-help booklet or repeated assessment s. At follow-up , fewer cognitive therapy patients ( 3 [ 11 % ] ) had PTSD compared with those receiving the self-help booklet ( 17 [ 61 % ] ; odds ratio , 12.9 ; 95 % confidence interval , 3.1 - 53.1 ) or repeated assessment s ( 16 [ 55 % ] ; odds ratio , 10.3 ; 95 % confidence interval , 2.5 - 41.7 ) . There was no indication that the self-help booklet was superior to repeated assessment s. On 2 measures , high end-state functioning at follow-up and request for treatment , the outcome for the self-help group was worse than for the repeated assessment s group . CONCLUSIONS Cognitive therapy is an effective intervention for recent-onset PTSD . A self-help booklet was not effective . The combination of an elevated initial symptom score and failure to improve with self-monitoring was effective in identifying a group of patients with early PTSD symptoms who were unlikely to recover without intervention A r and omized trial was performed in which imaginal exposure ( IE ) and cognitive therapy ( CT ) were compared in the treatment of chronic posttraumatic stress disorder ( PTSD ) . Patients who continued to meet PTSD caseness at the end of a 4-week symptom-monitoring baseline period ( n = 72 ) were r and omly allocated to either IE or CT . There was a significant improvement in all measures over treatment and at follow-up , although there were no significant differences between the 2 treatments at any assessment . A significantly greater number of patients who showed worsening over treatment received IE , although this effect was not found at follow-up . Patients who worsened showed a 
    Output:
    
Cognitive behavioral therapy was more effective than supportive counseling in preventing chronicity of PTSD symptoms ; however , in most available studies it remained unclear whether supportive counseling facilitated or retarded recovery , compared with no intervention .
A brief CBT program given in the first month of trauma was not superior to repeated assessment ; however , a course of CBT of up to 16 sessions given at 1 - 4 months after trauma was superior to self-help , repeated assessment , and no intervention .
These include the way of working through traumatic memories and the impact of the interventions on patients ' interpretations of their PTSD symptoms .