acute coronary syndromes [ acs ; i.e. , myocardial infarction ( mi ) , unstable angina ( ua ) ] are highly prevalent ( lloyd - jones et al . , 2010 ) , and survivors are at increased risk for recurrent mi and mortality in the subsequent year ( goldberg et al . , 2004 ; although this increased risk can be managed through adherence to medical advice , post - acs patients often exhibit poor adherence ( eagle et al . , 2005 ) , possibly due to underestimation of their risk for future mi recurrence . this may be particularly true for patients with posttraumatic stress disorder ( ptsd ) , an anxiety disorder that has been related to acs incidence ( kubzansky et al . , 2007 ) , acs recurrence ( edmondson et al . , 2011 ) , poor post - acs adherence ( shemesh et al . , 2004 ) , and acs risk behaviors ( cohen et al . , 2009 ) . it is widely known that affective states , and more abiding affective alterations due to psychological disorder , are related to risk perceptions . however , the complexity of the relationship between affect and risk perception is under - recognized , as the effect of emotions are influenced by the type and intensity of emotion , as well as the type of judgment being influenced ( pham , 2007 ) . for example , depression disrupts reasoning and effortful processing ( conway and giannopoulos , 1993 ; hartlage et al . , 1993 ) , and clinical anxiety is related poorer recall for pertinent information and organization of such information in memory ( mueller , 1978 ) , haphazard decision - making ( keinan , 1987 ) , and less thorough processing of persuasive arguments ( sanbonmatsu and kardes , 1988 ) . the estimation of risk for many future events is a difficult task under any circumstances , and the estimation of a future life - threatening event such as an mi immediately after experiencing an mi may be particularly difficult . it requires both some understanding of the base rate of mi , the added risk conferred by having already had an mi , and ( in this study ) a comparison of personal risk to normative risk . while the cognitive load associated with ptsd and the biases associated with anxiety more generally may influence risk perceptions , there is also evidence that when risk perceptions are related to actual subsequent outcomes , psychological disorder may be related to poor prediction and overconfidence due to neglect of base rate information , heightened perception of dissimilarity from others , and even undue optimism about the future ( dunning and story , 1991 ) . the association of ptsd to medical risk perceptions has never been estimated , particularly in the context of actual elevated risk due to ptsd . since risk perceptions are a primary motivator of adherence behaviors ( brewer et al . , 2004 ) , we assessed the relationship of probable ptsd to mi risk perceptions in hospitalized acs patients . participants were acs patients who had been treated in the columbia university medical center ( cumc ) ed and enrolled in the prescription use , lifestyle , stress evaluation ( pulse ) study , an ongoing , single site , observational , prospective study of patients with acs . the primary objectives of the parent study are to identify intermediary phenotypes of depression in acs patients and the behavioral , biological , and genetic mechanisms that may account for the excess acs recurrence and mortality risk associated with depression in acs patients . patients were eligible to participate if they were diagnosed with acs , as defined by ua , nstemi , or stemi , and diagnosis was confirmed by two independent cardiologists . patients were ineligible if they were under 18  years old , a prisoner , were deemed unable to comply with the study protocol or had a life expectancy less than 1  year , were not fluent in english or spanish , or evinced psychosis , bipolar disorder , or personality disorder . data for the present analyses are from a subset of the first 500 participants who also completed a ptsd screening measure in the 3- to 7-days post - acs ( n  =  420 ) . during hospitalization risk for having a heart attack in the next year compared to other men ( or women ) their age  on a 5-point scale ( 1 ,  much lower than average  to 5 ,  much higher than average  ) , and their confidence that they  could control their heart disease  on a 5-point scale ( 1 ,  not at all confident  to 5 ,  very confident  ) . patient - reported demographics and depressive symptoms ( i.e. , beck depression inventory , bdi sum score ; beck et al . , 1961 ) were also ascertained . the following clinical variables were derived from chart review : index acs type ( i.e. , mi or ua ) , global registry of acute coronary events ( grace ) risk score ( i.e. , 6-month post - acs mortality risk based upon previous mi , heart failure , and in - hospital cardiovascular markers ; goldberg et al . , 2004 ) , and charlson comorbidity score ( i.e. , index of 22 medical conditions weighted by mortality risk ; charlson et al . , 1994 ) . demographics , depressive symptoms , and perceived control have been associated with risk perceptions in previous research ( avis et al . , 1989 ; helweg - larsen and shepperd , 2001 ) . participants were screened 37  days after discharge from the hospital for ptsd symptoms in the previous three months using three items from the structured clinical interview for dsm - iv - ptsd ( scid - ptsd ; first et al . , 1995 ) . they reported whether they had ( 1 ) experienced a traumatic event (  such as a major disaster , very serious accident or fire , being physically assaulted or raped , seeing another person killed or dead , or badly hurt , or hearing about something horrible that has just happened to someone close to you  ) prior to their acs hospitalization , ( 2 ) whether the event came back  in nightmares , flashbacks , or thoughts you can not get rid of ,  and ( 3 ) whether the experience of  thoughts or feelings coming back  had happened in the past 3 months . participants who responded  yes  to all three items were categorized as screening positive for probable ptsd . in previous research , responses to these questions finally , five cardiologists blinded to ptsd status estimated the aggregate 1-year mi risk for all participants based on demographic data and clinical risk index scores . myocardial infarction risk perceptions were the dependent variable in a one - way ancova with probable ptsd screen as the grouping factor , and age , gender , race ( african - american versus other ) , ethnicity ( hispanic versus non - hispanic ) , index acs event type , grace , charlson , bdi , and self - confidence in heart disease control as covariates . participants were primarily male ( n  =  291 , 69% ) and hispanic ( n  =  287 , 68% ) or african - american ( n  =  83 , 20% ) with a mean age of 63    11 . for clinical variables , 161 participants ( 38% ) were hospitalized with mi , and the sample as a whole averaged 2 medical comorbidities . the average grace score for the sample was 88.8 ( 28.22 ) , indicating 38% average probability of death between hospitalization and 6  months post - discharge . the sample as a whole reported moderate confidence in their ability to control their heart disease [ mean  =  2.4 ( 1.2 ) ] . participants who screened positive for ptsd ( n  =  15 , 3.5% ) did not differ from those who screened negative on any covariate ( table 1 ) , except that they reported significantly more depressive symptoms ( 13.3 versus 9.2 , p  =  0.03 ) . overall , participants exhibited an optimistic bias in perceived mi risk , rating their risk as between average and below average [ mean risk estimate  =  2.6 ( 1.1 ) ] . patients risk perceptions ( figure 1 ) were unrelated to their grace risk score ( r  =  0.05 , p  =  0.31 ) , though qualitatively discrepant from cardiologists ratings [ between  above average  ( four cardiologists ) and  well above average ( one cardiologist ) ] . in the ancova [ f ( 9 , 406 )  =  9.36 , p <  0.001 , r ( adj )  =  0.15 ] , a positive screen for ptsd was associated with significantly lower perceived risk of mi relative to a negative screen [ 2.1 ( 1.0 ) versus 2.7 ( 1.1 ) ; p  =  0.03 ,   =  0.01 ] . significant covariates included confidence in ability to control heart disease ( p  <  0.001 ,   =  0.09 ) , charlson comorbidity score ( p  =  0.01 ,   =  0.02 ) , and hispanic ethnicity ( p  =  0.02 ,   =  0.01 ) . perceived 1-year myocardial infarction risk and clinician ratings of risk for patients who screened positive for probable ptsd versus those who screened negative . note : 0  =  average risk ; 1  =  above average risk ; 1  =  below average risk . this study is the first to assess mi risk perceptions in post - acs patients and to demonstrate a relationship between ptsd and increased optimistic bias . previous research suggested that ptsd might be related to less optimistic bias ( gidycz et al . , 2006 ) , but this previous research was not conducted among hospitalized patients . in contrast to laboratory experiments , psychological disorders have been associated with more pronounced optimistic bias in estimations of future events ( dunning and story , 1991 ) . further , it is possible that the hospital environment induces avoidance and numbing mechanisms that further minimize risk perceptions in patients with probable ptsd . it is also possible that a broader deficit in self - care gives rise to cognitive dissonance that requires a reduction in perceptions of future mi threat ( stone and cooper , 2001 ) . the self - care deficit and cognitive dissonance explanation is consistent with recent findings that ptsd is associated with longer delays between initial symptoms and presentation to the hospital in acs patients ( newman et al . , 2011 ) . there were no significant differences between the two groups on any demographic or clinical variable we measured , nor did the two groups differ in their confidence that they could control their heart disease . however , as expected , participants who screened positive for probable ptsd reported more depression symptoms . while depression is often thought to result in  depressive realism ,  there is considerable disagreement concerning the consistency , strength , and source of this effect , particularly outside the lab ( carson et al . , indeed , we found the opposite , that the more depressed group were less realistic about their risk for mi , in a manner similar to that found by dunning and story ( 1991 ) . limitations of this study include the use of a ptsd screening instrument which assesses only criterion a ( without specifying the type of trauma ) and criterion b. although the low prevalence of probable ptsd in this sample is noteworthy and has important clinical implications , it is not a statistical limitation as unbalanced designs in ancova tend to result in reduced power ( i.e. , bias the grand mean toward the larger sample ) . further , we reported statistical tests based on type iii sums of squares in ancova because estimates based on type iii sums of squares are not sample size dependent ( i.e. , effect estimates are not a function of group size ) . these results suggest that acs patients with ptsd may be excessively optimistic when estimating their true risk of cardiovascular morbidity . this optimistic bias may help to explain the decreased adherence previously described in post - acs patients with ptsd ( shemesh et al . , 2004 ) and , ultimately , the increased acs recurrence risk associated with ptsd ( edmondson et al . , 2011 ; von knel et al . , 2011 ) . the authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest .
posttraumatic stress disorder ( ptsd ) is related to acute coronary syndrome ( acs ; i.e. , myocardial infarction or unstable angina ) recurrence and poor post - acs adherence to medical advice . since risk perceptions are a primary motivator of adherence behaviors , we assessed the relationship of probable ptsd to acs risk perceptions in hospitalized acs patients ( n  =  420 ) . 
 participants completed a brief ptsd screen 37  days post - acs , and rated their 1-year acs recurrence risk relative to other men or women their age . 
 most participants exhibited optimistic bias ( mean recurrence risk estimate between  average  and  below average  ) . 
 further , participants who screened positive for current ptsd ( n  =  15 ) showed significantly greater optimistic bias than those who screened negative ( p  <  0.05 ) , after adjustment for demographics , acs severity , medical comorbidities , depression , and self - confidence in their ability to control their heart disease . 
 clinicians should be aware that psychosocial factors , and ptsd in particular , may be associated with poor adherence to medical advice due to exaggerated optimistic bias in recurrence risk perceptions .