participants were drawn from a national institute of mental healthfunded study of risk factors for the development of ptsd in a low socioeconomic , primarily african american urban population .
participants were recruited from waiting rooms in the diabetes , gynecology , and primary care medical ( nonpsychiatric ) clinics at grady memorial hospital , a publicly funded hospital in atlanta , georgia .
interviewers approached participants waiting for appointments . to be eligible for participation , subjects had to be at least 18 years old and able to give informed consent .
the investigation was carried out in accordance with the latest version of the declaration of helsinki and informed consent of the participants was obtained after the nature of the procedures had been fully explained .
after signing the informed consent approved by the emory institutional review board , an initial interview was administered with questionnaires regarding trauma history and psychological variables .
trained research assistants administered this interview by reading each question aloud to participants ; interviews took 4575 minutes to complete ( duration largely dependent on the participant 's trauma history and symptoms ) .
a more detailed and comprehensive assessment of psychological functioning was conducted in an associated study , which included a subset of participants who completed the initial assessment ( see gillespie et  al . , 2009 , for full details regarding study procedures ) .
the current study includes 260 females with a mean age of 39.76 years ( standard deviation [ sd ] = 11.73 years ) who completed both the initial and secondary assessments . the majority of the participants selfidentified as african american ( 96.9% , n = 252 ) .
the remaining ethnicities represented included caucasian ( 1.1% , n = 3 ) and mixed or other ( 2.0% , n = 5 ) .
this was a highly traumatized sample , with all participants reporting the experience of at least one type of trauma in their lifetime ( mean [ m ] = 4.97 , sd = 2.96 ) .
the ders ( gratz & roemer , 2004 ) is a psychometrically validated , selfreport , 36item measure of emotion regulation difficulties .
it measures several aspects of emotion regulation , including awareness and understanding of one 's emotions , acceptance of negative emotions , the ability to successfully engage in goaldirected behavior and control impulsive behavior when experiencing negative emotions , and the ability to use situationally appropriate emotion regulation strategies . for the present study ,
the internal consistency of the ders total scale was high (  = 0.92 ) .
the caps is an intervieweradministered , psychometrically validated diagnostic instrument measuring ptsd ( blake et  al . , 1990 , 1995 ) .
it includes items that rate social and occupational functioning , global ptsd symptom severity , and the validity of a participant 's responses .
the caps assesses current ptsd and yields a continuous measure of the severity of overall ptsd and the three dsmivtr symptom clusters ( i.e. , reexperiencing , avoidance and numbing , and arousal , or criterion b , c , and d , respectively ) .
the frequency and intensity scores for each of the 17 diagnostic criteria are summed to arrive at a total severity score , and each criterion also has a total severity score based on the individual items for the respective criterion ( five for criterion b , seven for criterion c , and five for criterion d ) . the mini ( sheehan et  al . , 1998 ) is a structured diagnostic interview that assesses mood , anxiety , substance use , and psychotic disorders based on dsmivtr criteria .
the mini has shown good reliability and validity across different samples ( lecrubier et  al . , 1997 ;
for the present study , only the current ad section was used . within our sample , 24.2% ( n = 63 ) affirmed to drinking three or more alcoholic drinks in a 6hour period on three or more occasions within the past year , and 6.9% met full dsmiv criteria for ad . for all analyses
, we created a continuous variable to measure ad in an effort to capture overall severity of ad symptoms .
the tei ( gillespie et  al . , 2009 ; schwartz et  al . , 2005 ) is a 14item screening instrument for lifetime history of traumatic events witnessed or experienced .
the tei was used in this investigation to assess total number of types of traumas exposed to in one 's lifetime ; therefore , the types of traumatic events either witnessed or experienced were summed to obtain an overall trauma load score .
the overall analytic approach was to examine the predictive utility of current ptsd symptoms and ed on reported ad symptoms .
. however , the level of skewness ( range : 0.421.66 ) as well as the level of kurtosis ( range : 0.631.43 ) in this sample fell within acceptable parameters for the sample size on all variables ( tabachnick & fidell , 2000 ) .
descriptive statistics of the sample and all variables of interest were computed and are presented in table 1 .
sd = standard deviation ; tei = traumatic events inventory ; mini = mini international neuropsychiatric interview ; ders = difficulties in emotion regulation scale ; caps = clinicianadministered ptsd scale .
then , based on the results of the correlational analyses , two hierarchical linear regression models were used to examine the unique predictive value of ptsd symptoms and ed ( total and separated by the individual dimensions of ed ) on ad symptoms . both because it will provide a more nuanced understanding of associations between variables and because results have differed by ptsd symptom cluster in previous research ( debell et  al . , 2014
; saladin , brady , dansky , & kilpatrick , 1995 ) , we analyzed the three symptom clusters of ptsd separately . because research has shown that rates of ad vary by age and trauma exposure ( kessler , berglund , et  al .
, 2005 ; turner & lloyd , 1995 ) , these variables were included as covariates in analyses . finally , mediation analyses were performed with indirect ( preacher & hayes , 2008 ) for spss to test whether ed had an indirect effect on the relationship between current avoidance and numbing ptsd symptoms and ad symptoms .
bootstrapping with 95% confidence intervals ( cis ) was used to determine significance of mediation effects .
bootstrapping is a particularly useful method for interpreting mediation analyses because it does not assume that sampling distributions of the indirect effects are normally distributed ( preacher & hayes , 2008 ) .
reexperiencing and hyperarousal symptoms were also controlled for in an effort to determine the specific association between avoidance and numbing and ad symptoms .
participants were drawn from a national institute of mental healthfunded study of risk factors for the development of ptsd in a low socioeconomic , primarily african american urban population .
participants were recruited from waiting rooms in the diabetes , gynecology , and primary care medical ( nonpsychiatric ) clinics at grady memorial hospital , a publicly funded hospital in atlanta , georgia .
interviewers approached participants waiting for appointments . to be eligible for participation , subjects had to be at least 18 years old and able to give informed consent .
the investigation was carried out in accordance with the latest version of the declaration of helsinki and informed consent of the participants was obtained after the nature of the procedures had been fully explained .
after signing the informed consent approved by the emory institutional review board , an initial interview was administered with questionnaires regarding trauma history and psychological variables .
trained research assistants administered this interview by reading each question aloud to participants ; interviews took 4575 minutes to complete ( duration largely dependent on the participant 's trauma history and symptoms ) .
a more detailed and comprehensive assessment of psychological functioning was conducted in an associated study , which included a subset of participants who completed the initial assessment ( see gillespie et  al . , 2009 , for full details regarding study procedures ) .
the current study includes 260 females with a mean age of 39.76 years ( standard deviation [ sd ] = 11.73 years ) who completed both the initial and secondary assessments . the majority of the participants selfidentified as african american ( 96.9% , n = 252 ) .
the remaining ethnicities represented included caucasian ( 1.1% , n = 3 ) and mixed or other ( 2.0% , n = 5 ) .
this was a highly traumatized sample , with all participants reporting the experience of at least one type of trauma in their lifetime ( mean [ m ] = 4.97 , sd = 2.96 ) .
the ders ( gratz & roemer , 2004 ) is a psychometrically validated , selfreport , 36item measure of emotion regulation difficulties .
it measures several aspects of emotion regulation , including awareness and understanding of one 's emotions , acceptance of negative emotions , the ability to successfully engage in goaldirected behavior and control impulsive behavior when experiencing negative emotions , and the ability to use situationally appropriate emotion regulation strategies . for the present study ,
the internal consistency of the ders total scale was high (  = 0.92 ) .
the caps is an intervieweradministered , psychometrically validated diagnostic instrument measuring ptsd ( blake et  al .
it includes items that rate social and occupational functioning , global ptsd symptom severity , and the validity of a participant 's responses .
the caps assesses current ptsd and yields a continuous measure of the severity of overall ptsd and the three dsmivtr symptom clusters ( i.e. , reexperiencing , avoidance and numbing , and arousal , or criterion b , c , and d , respectively ) .
the frequency and intensity scores for each of the 17 diagnostic criteria are summed to arrive at a total severity score , and each criterion also has a total severity score based on the individual items for the respective criterion ( five for criterion b , seven for criterion c , and five for criterion d ) . the mini ( sheehan et  al . , 1998 ) is a structured diagnostic interview that assesses mood , anxiety , substance use , and psychotic disorders based on dsmivtr criteria .
the mini has shown good reliability and validity across different samples ( lecrubier et  al . , 1997 ;
for the present study , only the current ad section was used . within our sample , 24.2% ( n = 63 ) affirmed to drinking three or more alcoholic drinks in a 6hour period on three or more occasions within the past year , and 6.9% met full dsmiv criteria for ad . for all analyses
, we created a continuous variable to measure ad in an effort to capture overall severity of ad symptoms .
the tei ( gillespie et  al . , 2009 ; schwartz et  al . ,
2005 ) is a 14item screening instrument for lifetime history of traumatic events witnessed or experienced .
the tei was used in this investigation to assess total number of types of traumas exposed to in one 's lifetime ; therefore , the types of traumatic events either witnessed or experienced were summed to obtain an overall trauma load score .
the ders ( gratz & roemer , 2004 ) is a psychometrically validated , selfreport , 36item measure of emotion regulation difficulties .
it measures several aspects of emotion regulation , including awareness and understanding of one 's emotions , acceptance of negative emotions , the ability to successfully engage in goaldirected behavior and control impulsive behavior when experiencing negative emotions , and the ability to use situationally appropriate emotion regulation strategies . for the present study ,
the internal consistency of the ders total scale was high (  = 0.92 ) .
the caps is an intervieweradministered , psychometrically validated diagnostic instrument measuring ptsd ( blake et  al . , 1990 , 1995 ) .
it includes items that rate social and occupational functioning , global ptsd symptom severity , and the validity of a participant 's responses .
the caps assesses current ptsd and yields a continuous measure of the severity of overall ptsd and the three dsmivtr symptom clusters ( i.e. , reexperiencing , avoidance and numbing , and arousal , or criterion b , c , and d , respectively ) .
the frequency and intensity scores for each of the 17 diagnostic criteria are summed to arrive at a total severity score , and each criterion also has a total severity score based on the individual items for the respective criterion ( five for criterion b , seven for criterion c , and five for criterion d ) .
the mini ( sheehan et  al . , 1998 ) is a structured diagnostic interview that assesses mood , anxiety , substance use , and psychotic disorders based on dsmivtr criteria .
the mini has shown good reliability and validity across different samples ( lecrubier et  al . , 1997 ;
for the present study , only the current ad section was used . within our sample , 24.2% ( n = 63 ) affirmed to drinking three or more alcoholic drinks in a 6hour period on three or more occasions within the past year , and 6.9% met full dsmiv criteria for ad . for all analyses
, we created a continuous variable to measure ad in an effort to capture overall severity of ad symptoms .
the tei ( gillespie et  al . , 2009 ; schwartz et  al . ,
2005 ) is a 14item screening instrument for lifetime history of traumatic events witnessed or experienced .
the tei was used in this investigation to assess total number of types of traumas exposed to in one 's lifetime ; therefore , the types of traumatic events either witnessed or experienced were summed to obtain an overall trauma load score .
the overall analytic approach was to examine the predictive utility of current ptsd symptoms and ed on reported ad symptoms .
. however , the level of skewness ( range : 0.421.66 ) as well as the level of kurtosis ( range : 0.631.43 ) in this sample fell within acceptable parameters for the sample size on all variables ( tabachnick & fidell , 2000 ) .
descriptive statistics of the sample and all variables of interest were computed and are presented in table 1 .
sd = standard deviation ; tei = traumatic events inventory ; mini = mini international neuropsychiatric interview ; ders = difficulties in emotion regulation scale ; caps = clinicianadministered ptsd scale .
then , based on the results of the correlational analyses , two hierarchical linear regression models were used to examine the unique predictive value of ptsd symptoms and ed ( total and separated by the individual dimensions of ed ) on ad symptoms . both because it will provide a more nuanced understanding of associations between variables and because results have differed by ptsd symptom cluster in previous research ( debell et  al . ,
2014 ; saladin , brady , dansky , & kilpatrick , 1995 ) , we analyzed the three symptom clusters of ptsd separately . because research has shown that rates of ad vary by age and trauma exposure ( kessler , berglund , et  al .
, 2005 ; turner & lloyd , 1995 ) , these variables were included as covariates in analyses .
finally , mediation analyses were performed with indirect ( preacher & hayes , 2008 ) for spss to test whether ed had an indirect effect on the relationship between current avoidance and numbing ptsd symptoms and ad symptoms .
bootstrapping with 95% confidence intervals ( cis ) was used to determine significance of mediation effects .
bootstrapping is a particularly useful method for interpreting mediation analyses because it does not assume that sampling distributions of the indirect effects are normally distributed ( preacher & hayes , 2008 ) .
reexperiencing and hyperarousal symptoms were also controlled for in an effort to determine the specific association between avoidance and numbing and ad symptoms .
to determine the extent of association between our predictor variables and current ad symptoms , we first calculated pearson correlation coefficients .
as shown in table 2 , of the current ptsd variables measured , only ptsd symptom cluster c ( avoidance and numbing ) was significantly positively correlated with current ad symptoms ( p < 0.01 ) .
total ed and all six dimensions of ed measured by the ders also were significantly positively correlated with current ad symptoms ( p  0.001 ) .
furthermore , overall ed and all six dimensions of ed were significantly correlated with each ptsd symptom cluster ( p < 0.01 ) , except for a nonsignificant association between lack of emotional awareness and ptsd symptom cluster b. a hierarchical linear regression model was first run to test the differential associations of ptsd symptoms and ed with current ad symptoms .
age and overall trauma load were entered in the first step of each regression as covariates . as shown in table 3 , when the three ptsd symptom clusters were entered into the second step of the regression model , they were significantly predictive of ad symptoms ( p < 0.05 ) .
of the three symptom clusters included in the model , only avoidance and numbing symptoms were predictive ( p < 0.01 ) of ad symptoms above and beyond the effects of age and trauma load . when overall ed was included in the model in step 3 , the effect of avoidance and numbing symptoms was no longer significant .
overall , ed was significantly predictive of ad symptoms ( p < 0.001 ) , suggesting that ed may mediate the relationship between avoidance and numbing symptoms of ptsd and current ad symptoms . age and trauma exposure were not significantly predictive of ad symptoms at any step .
linear regression model predicting current alcohol dependence symptom severity from current ptsd symptoms and overall ed 
 note .
ptsd = posttraumatic stress disorder ; ed = emotion dysregulation ; tei = traumatic events inventory ; ders = difficulties in emotion regulation scale . 

we also examined the effects of the six dimensions of ed independently to determine if there were differential effects ( see table 4 ) .
similar results emerged in step 2 of this model ; more specifically , only avoidance and numbing symptoms were significantly predictive of ad symptoms ( p < 0.01 ) . in step 3 ,
ed dimensions were significantly predictive of current ad symptoms , accounting for 14% of additional variance in explaining alcohol symptoms independent of age , trauma exposure , and current ptsd symptoms .
as shown in table 4 , the only ed dimension significant at step 3 was difficulty with goal directed behavior in the presence of strong emotions after controlling for the effects of age , trauma exposure , ptsd symptoms , and the other dimensions of ed .
again , avoidance and numbing ptsd symptoms were no longer significant when ed dimensions were included in the model , suggesting a potential mediation effect .
linear regression model predicting current alcohol dependence symptom severity from current ptsd symptoms and the six dimensions of ed 
 note .
ptsd = posttraumatic stress disorder ; ed = emotion dysregulation ; tei = traumatic events inventory ; ders = difficulties in emotion regulation scale . 

we used preacher and hayes ( 2008 ) indirect to formally test the mediation model suggested by the linear regression analyses .
age , trauma load , and caps subscales for reexperiencing symptoms ( criterion b ) and hyperarousal symptoms ( criterion d ) were entered in the model as covariates . as shown in figure 1 , overall ed showed a full indirect effect on the relationship between avoidance and numbing ptsd symptoms and current ad symptoms ( overall model : r = 0.15 , f = 7.49 , p < 0.001 ; bias corrected 95% ci [ 0.01 , 0.04 ] ) .
a similar full indirect effect was found when running the mediation model using the difficulty with goaldirected behavior dimension of the ders ( overall model : r = 0.13 , f = 6.42 , p < 0.001 ; bias corrected 95% ci [ 0.01 , 0.03 ] ) .
again , age , trauma load , and caps subscales for reexperiencing symptoms ( criterion b ) and hyperarousal symptoms ( criterion d ) were entered in the model as covariates and none of the covariates were significant .
in support of previous research ( e.g. , brady et  al . , 2004 ; kessler et  al . , 1995 ; kessler , chiu , et  al . , 2005 ;
mcfarlane , 1998 ; stewart et  al . , 1998 ; swendsen et  al . ,
2010 ) , we found a significant association between ptsd symptoms and ad symptoms in this sample of urban , minority females . when examining the specific ptsd symptom clusters , only avoidance and numbing ptsd symptoms were significantly correlated to ad symptoms .
lifetime trauma load was not significantly related to ad , suggesting that within this sample it was not the number of traumatic events experienced but the presence of anxiety symptoms attributable to ptsd that contributed to ad .
this adds to research suggesting that alcohol is used as an avoidance strategy in ptsd patients ( brady et  al .
, 2004 ; hayes et  al . , 1996 ) and highlights that trauma load itself may not increase risk for dependence , although it may increase risk for the development of ptsd which might then increase risk for alcohol use problems .
our results also showed that all dimensions of ed were positively significantly correlated with ad , supporting previous findings that ed and ad are associated ( bonnmiller et  al .
, we also found that ed had a full indirect effect on the relationship between current ptsd avoidance and numbing symptoms and current ad symptoms among traumatized females .
moreover , difficulties engaging in goaldirected behaviors had an indirect effect on this relationship above and beyond the other dimensions of ed in this sample .
these findings suggest that poor emotion regulation in general , and an inability to stay focused on goaldirected behaviors when faced with strong emotions in particular , may help explain why women with ptsd are driven to ad .
individuals with ptsd may experience greater negative emotions , and if they do not have adequate emotion regulation capabilities , then they might use alcohol to avoid those negative emotions ( cooper , russell , skinner , frone , & mudar , 1992 ; hayes et  al .
, 1996 ; khantzian , 1997 ; stewart , zvolensky , & eifert , 2002 ; tull et  al . , 2007 ) .
the specific use of alcohol as an avoidance strategy may help explain why there was only a significant association between ad symptoms and the avoidance and numbing symptom cluster , although that can not be determined from the current study based on its crosssectional nature .
it is unclear why having difficulties with goaldirected behaviors in the presence of strong emotions in particular was related to ad in these women .
one possibility is that if negative emotions repeatedly resurface while attempting to focus and engage in goaldirected behavior , then women with a tendency to try to control rather than modulate emotions may choose alcohol as a way to numb themselves from the negative situation
. this behavior pattern would be analogous to the selfmedication theory , whereby individuals suffering from ptsd turn to alcohol abuse as a way to avoid fearful memories and to dampen negative emotions brought on by those memories ( brady et  al .
, 2004 ; khoury , tang , bradley , cubells , & ressler , 2010 ; leeies , pagura , sareen , & bolton , 2010 ; quitkin , rifkin , kaplan , & klein , 1972 ; read , merrill , griffin , bachrach , & khan , 2014 ) . selfmedicating with alcohol among women with ptsd may involve ed processes .
lehavot , stappenbeck , luterek , kaysen , and simpson ( 2014 ) found that coping motives ( i.e. , drinking to avoid negative affect ) were associated with amount of alcohol use in women .
additional research is needed to determine how in fact ed does relate to the selfmedication theory in traumatized females with ptsd .
future studies of urban females suffering from ptsd would benefit from including direct measures of selfmedication and drinking motives in addition to ed dimensions to further delineate how these constructs are interrelated with each other and with alcohol problems .
the results of this study provide further support for targeting emotion regulation skills in therapy for traumatized individuals .
interventions for individuals suffering from ptsd and ad symptoms should be broad enough to support the needs of comorbidities and underlying areas of dysfunction ( e.g. , ed ) .
the most common and effective therapy for ptsd treatment is prolonged exposure therapy ( see mrkved et  al . , 2014 , for review ) . while early studies warned against antagonistic effects of exposure therapy in people with comorbid addiction disorders ( e.g. , becker , zayfert , & anderson , 2004 ; pitman et  al . ,
1991 ) , studies that are more recent have shown successful treatment in populations with comorbid ptsd and ad using various types of exposure therapy ( e.g. , berenz , rowe , schumacher , stasiewicz , & coffey , 2012 ; nosen , littlefield , schumacher , stasiewicz , & coffey , 2014 ) .
it is possible that targeting emotion regulation skills in addition to traumafocused treatment would be beneficial for traumatized females .
theoretically , improving emotion regulation abilities in women suffering from ptsd and ad may lessen ad symptoms , allowing for a more successful intervention of ptsd symptoms later in treatment .
this has been shown in other populations , such as those with exposure to childhood sexual abuse ( cloitre , koenen , cohen , & han , 2002 ; cloitre , stovallmcclough , miranda , & chemtob , 2004 ) , and researchers should continue to examine how best to incorporate emotion regulation training into treatment protocols .
we can not say for certain that the onset of ptsd and ed symptoms preceded the onset of ad symptoms in every participant , and therefore we can not determine directional causality .
prospective , longitudinal studies are required to examine the temporal onset of ed , ptsd , and ad symptoms . also , although the ders is a validated measure of ed , it is inherently biased by its selfreport nature
. finally , our sample was largely lowincome african american females , which limits the generalizability of our findings to other populations . however , this weakness is balanced by the public health importance of studying these variables in an often underresearched and underserved population with such high rates of trauma exposure as well as mental health problems .
we can not say for certain that the onset of ptsd and ed symptoms preceded the onset of ad symptoms in every participant , and therefore we can not determine directional causality .
prospective , longitudinal studies are required to examine the temporal onset of ed , ptsd , and ad symptoms . also , although the ders is a validated measure of ed , it is inherently biased by its selfreport nature . finally , our sample was largely lowincome african american females , which limits the generalizability of our findings to other populations
. however , this weakness is balanced by the public health importance of studying these variables in an often underresearched and underserved population with such high rates of trauma exposure as well as mental health problems .
this study contributes to the research on ptsd and ad comorbidity by identifying a potential underlying factor that may help explain this wellestablished relationship . in a highly traumatized , low socioeconomic , urban sample of women
, we found that ed had a full indirect effect on the association between avoidance and numbing ptsd symptoms and ad symptoms ; therefore , ed may be an important component of what drives this relationship .
the current findings provide support for growing literature suggesting the addition of therapeutic interventions for emotion regulation difficulties in traumatized patient populations , especially those with comorbid ptsd and ad .
 objectivethe purpose of this study was to examine how emotion dysregulation ( ed ) might help explain the relationship between posttraumatic stress disorder ( ptsd ) and alcohol dependence ( ad ) symptoms in females.methodparticipants included 260 women from primary , diabetes , and gynecological clinics of an urban public hospital . 
 this is a primarily african american sample ( 96.9% ) , including individuals reporting exposure to at least 1 traumatic event . 
 we examined the associations and predictability patterns between severity of ptsd symptoms , ed , and ad symptoms.resultsusing linear regression analyses , ptsd avoidance and numbing symptoms and ed were significant predictors of ad symptoms . 
 when looking at specific dimensions of ed , one 's inability to engage in goaldirected behavior under strong emotional influences showed a full indirect effect on the relationship between ptsd avoidance and numbing symptoms and ad symptoms.conclusionour findings suggest that having poor emotion regulation skills may help explain why females with ptsd become dependent on alcohol . 
Method
Procedure
Participants
Measures
Difficulties in Emotion Regulation Scale (DERS)
ClinicianAdministered PTSD Scale
MINI International Neuropsychiatric Interview
Traumatic Events Inventory (TEI)
Statistical Analysis
Results
Discussion
Limitations
Conclusion