Posttraumatic stress disorder and major depressive disorder: investigating the role of overlapping symptoms in diagnostic comorbidity

Studies of posttraumatic stress disorder (PTSD) have found high levels of comorbid major depressive disorder (MDD). One reason suggested for the comorbidity is the symptom overlap (contaminated symptoms) between the disorders. The present study investigated the contribution of contaminated symptoms (anhedonia, concentration, and sleep problems) to the comorbidity of PTSD and MDD. PTSD symptoms were subdivided into two groups: the contaminated symptoms and the 14 unique symptoms. It was speculated that if the contaminated symptoms are responsible for the comorbidity, then they will show less specificity than the unique symptoms, will be less highly correlated with a PTSD symptom total count, and be more frequently endorsed in PTSD patients with than without MDD. These hypotheses were tested in a sample (N = 1300) of psychiatric outpatients, 260 of whom had lifetime PTSD. None of the hypotheses were supported, thereby suggesting that the comorbidity between PTSD and MDD is not an artifact of symptom overlap.     

Comorbidity, impairment, and suicidality in subthreshold PTSD

OBJECTIVE: Reliance on the categorical model of psychiatric disorders has led to neglected study of posttraumatic sequelae that fall short of full criteria for posttraumatic stress disorder (PTSD). Substantial disability and suicidal risk is associated with subthreshold PTSD, but this association has not been well studied. In addition, no studies have examined the role of comorbidity in explaining disability and impairment in subthreshold PTSD. METHOD: On National Anxiety Disorders Screening Day 1997, 2,608 out of 9,358 individuals screened for affective and anxiety disorders at 1,521 sites across the United States reported at least one PTSD symptom of at least 1 month's duration. Impairment, comorbid anxiety disorders, major depressive disorder, and rates of suicidality were determined and compared for individuals with no, one, two, three, or four (full PTSD) symptoms on a screening questionnaire. Regression analyses examined the relative contribution of subthreshold PTSD and comorbid disorders to impairment and suicidal ideation. RESULTS: Impairment, number of comorbid disorders, rates of comorbid major depressive disorder, and current suicidal ideation increased linearly and significantly with each increasing number of subthreshold PTSD symptoms. Individuals with subthreshold PTSD were at greater risk for suicidal ideation even after the authors controlled for the presence of comorbid major depressive disorder. CONCLUSIONS: Higher numbers of subthreshold PTSD symptoms were associated with greater impairment, comorbidity, and suicidal ideation. Disability and impairment found in previous studies of subthreshold PTSD symptoms may be related in part to the presence of comorbid disorders. However, the presence of subthreshold PTSD symptoms significantly raised the risk for suicidal ideation even after the authors controlled for major depressive disorder. Given the broad public health implications of these findings, more efforts are needed to identify subthreshold PTSD symptoms in clinical populations, epidemiologic surveys, and treatment studies.     

Cortisol and catecholamines in posttraumatic stress disorder: an epidemiologic community study

BACKGROUND: Prior research has connected posttraumatic stress disorder (PTSD) to increased levels of catecholamines. However, studies of cortisol levels have produced mixed results. OBJECTIVE: To examine urinary catecholamine and cortisol levels in individuals with PTSD in a community sample. DESIGN: A representative cohort of young adult community residents, assessed periodically during a 10-year period for exposure to trauma and PTSD, was used to select a subset for urine collection studies conducted in a sleep laboratory across 2 consecutive nights and the intermediate day. SETTING: The sample of young adults was randomly selected from a large health maintenance organization and is representative of the geographic area except for the extremes of the socioeconomic status range. PARTICIPANTS: A subsample was selected from the 10-year follow-up cohort (n = 913; 91.1% of the initial sample). Eligibility criteria were: (1) persons exposed to trauma during the preceding 5 years, (2) other individuals who met PTSD criteria, and (3) a random preselected subsample. Of 439 eligible individuals, 292 (66.5%) participated, including 69 with lifetime PTSD. MAIN OUTCOME MEASURES: Measures of cortisol and catecholamine levels in urine. RESULTS: The lifetime PTSD group demonstrated significantly higher catecholamine levels than the group exposed to trauma without PTSD and the nonexposed group. Individuals exposed to trauma without PTSD demonstrated significantly lower urine catecholamine levels than the nonexposed and the PTSD groups. Mean cortisol levels did not differ across groups. When analyzed by comorbidity with major depressive disorder (MDD), the PTSD-only group did not differ in cortisol levels from the groups with neither PTSD nor MDD. Women with MDD plus PTSD demonstrated significantly higher cortisol levels than women with neither disorder or with either disorder alone. CONCLUSIONS: Trauma per se does not lead to sustained increases in cortisol or catecholamine levels. Posttraumatic stress disorder is associated with higher catecholamine levels. In contrast, persons with PTSD had neither an increase nor a decrease in mean urinary cortisol levels. Women with PTSD and comorbid MDD had higher cortisol levels.     

Impaired fear inhibition is a biomarker of PTSD but not depression

Background: A central problem in posttraumatic stress disorder (PTSD) is a reduced capacity to suppress fear under safe conditions. Previously, we have shown that combat‐related PTSD patients have impaired inhibition of fear‐potentiated startle (FPS). Given the high comorbidity between PTSD and depression, our goal was to see whether this impairment is specific to PTSD, or a non‐specific symptom associated with both disorders. Methods: Fear‐potentiated startle was assessed in 106 trauma‐exposed individuals divided into four groups: (a) No diagnosis control, (b) PTSD only, (c) major depression (MDD) only, and (d) comorbid PTSD and MDD. We used a novel conditional discrimination procedure, in which one set of shapes (the danger signal) was paired with aversive airblasts to the throat, and different shapes (the safety signal) were presented without airblasts. The paradigm also included fear inhibition transfer test. Results: Subjects with comorbid MDD and PTSD had higher FPS to the safety signal and to the transfer test compared to controls and MDD only subjects. In contrast to the control and MDD groups, the PTSD and comorbid PTSD and MDD groups did not show fear inhibition to safety cues. Conclusions: These results suggest that impaired fear inhibition may be a specific biomarker of PTSD symptoms. Depression and Anxiety, 2010. © 2010 Wiley‐Liss, Inc.     

Saliva cortisol in posttraumatic stress disorder: a community epidemiologic study.

BACKGROUND: Stress activates the hypothalamic-pituitary-adrenal (HPA) axis, so it was expected that posttraumatic stress disorder (PTSD) would be associated with activation of this axis; however, studies have found both increased and decreased cortisol in PTSD. To address this question, we collected saliva cortisol at home in a subsample of a longitudinal epidemiologic sample. METHODS: Six hundred eighty-four persons randomly selected from the total sample of 913 were requested to collect saliva samples upon awakening and in the early evening. Of these, 538 responded with samples, 516 of whom met inclusion criteria. These were 68 exposed to trauma with lifetime PTSD, 265 exposed to trauma with no PTSD, and 183 never exposed to trauma. RESULTS: In a comparison of these three groups, lifetime PTSD revealed elevated evening saliva cortisol compared with exposed/no PTSD. When lifetime comorbidity with major depressive disorder (MDD) was included in the analysis, only persons with comorbid PTSD and MDD showed this evening elevation in cortisol. Persons with PTSD alone (never MDD) showed normal saliva cortisol levels, as did subjects with lifetime MDD alone. CONCLUSIONS: Neither exposure to trauma nor PTSD alone is associated with alterations in saliva cortisol; however, elevated cortisol is found in PTSD comorbid with lifetime MDD.     

Posttraumatic stress disorder in hospitalized adolescents: psychiatric comorbidity and clinical correlates

OBJECTIVE: To describe the diagnostic comorbidity and clinical correlates of posttraumatic stress disorder (PTSD) in adolescent psychiatric inpatients. METHOD: Seventy-four adolescent inpatients were given a structured diagnostic interview, the revised version of the Diagnostic Interview for Children and Adolescents, and a battery of standard self-report measures to assess general trauma exposure, posttraumatic stress symptoms, suicidal behavior, dissociation, and depression. RESULTS: Ninety-three percent of subjects reported exposure to at least one traumatic event such as being a witness/victim of community violence, witnessing family violence, or being the victim of physical/sexual abuse. Thirty-two percent of subjects met diagnostic criteria for current PTSD, with sexual abuse cited as the most common traumatic stressor in 69% of PTSD cases. Girls were significantly more likely to develop PTSD than boys, although the total number of types of trauma did not differ by gender. Compared with psychiatric controls, male youngsters with PTSD were significantly more likely to have comorbid diagnoses of eating disorders, other anxiety disorders, and somatization disorder. Furthermore, male and female youngsters with PTSD were significantly more likely to have attempted suicide and report greater depressive and dissociative symptoms. CONCLUSION: In clinical populations of hospitalized adolescents exposed to multiple forms of trauma, PTSD is a common, but highly comorbid disorder. Specific multimodal assessments and treatments targeted to both PTSD and its comorbidity profile are warranted.     

Specificity of posttraumatic stress disorder symptoms: an investigation of comorbidity between posttraumatic stress disorder symptoms and depression in treatment-seeking veterans

In response to high levels of comorbidity and symptom overlap between posttraumatic stress disorder (PTSD), major depressive disorder (MDD), and other disorders, much attention has been devoted to the role of specific and nonspecific symptoms among the disorders. The present study investigated the overlapping symptoms of PTSD and MDD in treatment-seeking veterans. Exploratory factor analyses were used to identify latent factors of both self-reported and clinician-rated symptoms of PTSD and MDD. Results of exploratory factor analyses supported a 2-factor model representing symptoms of depression and PTSD; however, a subset of PTSD symptoms, characterized by emotional numbing and dysphoria, loaded onto the depression factor, rather than the PTSD factor. These nonspecific PTSD symptoms were predictive of comorbid MDD and increased depression symptomatology in patients with PTSD. Together, these findings demonstrate the importance of accounting for nonspecific symptoms in diagnosis and treatment of PTSD, highlighting a need for revisions to our current diagnostics.     

Effect of depression on recovery from PTSD

It has been suggested that the treatment strategy needs to be reviewed and changed if depression occurs in patients with posttraumatic stress disorder (PTSD). We analyzed data extracted from the Marmara Epidemiological Survey (MES) which had examined 683 survivors at 3 years after a devastating earthquake. Fifty three cases (40.5%) out of the 131 cases with PTSD had also been diagnosed with MDD. Comorbid PTSD and MDD group has significantly lower rates of recovery from PTSD in comparison to PTSD without MDD (26.4% vs. 47.4% respectively). Rates of past psychiatric disorder and past traumatic experience were significantly more frequent among the comorbid group. Moreover, comorbidity of PTSD and MDD was clearly associated with greater psychological distress, more severe PTSD, and diminished perceived social support. Past psychiatric disorder, General Health Questionnaire (GHQ-12) and Multidimensional Scale of Perceived Social Scale (MSPSS) total scores succeeded in predicting the comorbidity of PTSD and MDD significantly.     

A Study of a ‘Transactional’ Psychotherapy

This study investigated the extent of posttraumatic stress disorder (PTSD) and psychiatric comorbidity among the 2010 flood victims in Pakistan and its relationship with disaster exposure characteristics, cognitive distortions, and emotional suppression. One hundred and thirty-one (F = 89, M = 42) flood victims were assessed using the Posttraumatic Diagnostic Scale, the General Health Questionnaire-28, the Cognitive Distortion Scales, and the Courtauld Emotional Control Scale. The results showed that all victims met the diagnostic criteria for PTSD and scored above the cut-off for psychiatric caseness. Partial least squares modelling showed that disaster exposure characteristics were significantly correlated with PTSD and psychiatric comorbidity. Disaster exposure characteristics were also significantly associated with cognitive distortions which in turn were also significantly associated with PTSD and psychiatric comorbidity. Cognitive distortions were also correlated with emotional suppression which, however, was not associated with PTSD or psychiatric comorbidity. To conclude, the flood victims reported PTSD and psychiatric comorbid symptoms which were related to their subjective exposure to the flood. Such exposure led to the development of dysfunctional thinking patterns which in turn influenced distress symptoms.     

Does comorbid anxiety or depression affect clinical outcomes in patients with post-traumatic stress disorder and alcohol use disorders?

Post-traumatic stress disorder (PTSD) is commonly comorbid with other psychiatric disorders, including substance use disorders. In spite of this, pharmacologic treatment trials for PTSD often exclude individuals with significant psychiatric comorbidity. This study is a post hoc analysis of a 12-week double-blind placebo-controlled trial investigating sertraline in the treatment of patients with comorbid PTSD and an alcohol use disorder. Individuals with additional anxiety and affective disorders were included. Patients (N = 93) were stratified into four groups depending on presence or absence of additional anxiety or depressive disorders and evaluated for the effects of comorbidity on PTSD symptoms, depressive symptoms, and drinking behaviors. We hypothesized that additional comorbidity would be associated with poorer outcomes. Patients in all four subgroups showed marked and clinically significant improvement in alcohol drinking behaviors over the course of the study. For the entire sample, over the course of the 12 weeks, mean drinks per drinking day fell from 13.0 +/- 8.4 (SD) to 3.0 +/- 5.0 (SD); t = 10.2, df = 92, P <.000. There were, however, no significant differences among groups. Patients in all four groups showed moderate improvement in Hamilton Depression Rating Scale (HAMD) scores and Clinician-Administered PTSD scale (CAPS) scores at endpoint. For the entire sample, mean CAPS scores fell from 59.3 +/- 19.4 (SD) to 40.8 +/- 26.0, t = 8.9, df = 92, P <.000. Mean HAMD scores fell from 17. 9 +/- 6.7 (SD) at baseline to 11.8 +/- 9.4 (SD) at endpoint; t = 6.7, df = 92, P <.000. There were, however, no significant differences among groups for change in HAM-D or CAPS scores. Hence, contrary to our hypothesis, having additional anxiety or mood disorder comorbidity did not decrease treatment response in individuals with comorbid PTSD and an alcohol use disorder.     

Psychotic symptoms in combat-related posttraumatic stress disorder

BACKGROUND: Posttraumatic stress disorder (PTSD) is known often to be comorbid with other anxiety, mood, and substance use disorders. Psychotic symptoms have also been noted in PTSD and have been reported to be more common in Hispanic veterans. However, the occurrence of psychotic symptoms, including the degree to which they are accounted for by comorbid disorders, have received limited systematic investigation. Our study objectives were to assess psychotic symptoms according to DSM-III-R criteria in patients with a primary diagnosis of combat-related PTSD and determine the associations of those symptoms with psychiatric comorbidity and ethnicity. METHOD: Fifty-three male combat veterans consecutively admitted to a PTSD rehabilitation unit were assessed for psychotic symptoms and Axis I disorders. Ninety-one percent were Vietnam veterans; 72% were white, 17% were Hispanic, and 11% were black. Associations between psychotic symptoms and comorbid depression, substance use disorders, and minority status were compared by chi-square analyses; associations between psychotic symptoms and both PTSD and dissociative symptom severity were compared by t test analysis. RESULTS: Forty percent of patients reported a psychotic symptom or symptoms in the preceding 6 months. These symptoms featured auditory hallucinations in all but 1 case. The psychotic symptoms typically reflected combat-themes and guilt, were nonbizarre, and were not usually associated with formal thought disorder or flat or inappropriate affect. Psychotic symptoms were significantly associated with current major depression (p < .02), but not with alcohol or drug abuse or with self-rated PTSD and dissociation severity. Psychotic symptoms and current major depression were more common in minority (black and Hispanic) than white veterans (p < .002). CONCLUSION: Psychotic symptoms can be a feature of combat-related PTSD and appear to be associated with major depression. The association with minority status may be a function of comorbidity.     

Examining the relation between posttraumatic stress disorder and suicidal ideation in an OEF/OIF veteran sample

This study examined the relation between posttraumatic stress disorder (PTSD) and suicidal ideation among U.S. military veterans deployed during Operation Enduring Freedom and/or Operation Iraqi Freedom. Specific aims included investigation of (1) whether PTSD was associated with suicidal ideation after controlling for combat exposure and history of suicide attempt(s), (2) whether PTSD was associated with suicidal ideation absent a co-occurring depressive disorder (MDD) or alcohol use disorder (AUD), (3) whether co-occurring MDD or AUD increased risk of suicidal ideation among those with PTSD and (4) whether PTSD/MDD symptom clusters were differentially associated with suicidal ideation. Results pointed to unique effects associated with prior suicide attempt(s), PTSD and MDD. PTSD-diagnosed participants with co-occurring MDD or AUD were not significantly more likely to endorse suicidal ideation than PTSD-diagnosed participants without such comorbidity. The ‘emotional numbing’ cluster of PTSD symptoms and the ‘cognitive-affective’ cluster of MDD symptoms were uniquely associated with suicidal ideation.     

Corticotropin-releasing factor in posttraumatic stress disorder (PTSD) with secondary psychotic symptoms, nonpsychotic PTSD, and healthy control subjects.

BACKGROUND: Recent studies have reported a high comorbidity between posttraumatic stress disorder (PTSD) and psychotic symptoms, and it has been hypothesized that PTSD with comorbid psychosis is a severe form of PTSD. Few studies have examined the neurobiology of PTSD with comorbid psychosis. If PTSD with secondary psychotic symptoms (PTSD-SP) is a severe form of PTSD, then it might be expected to show more extreme perturbations in the neuroendocrine patterns that characterize PTSD. METHODS: Patients with PTSD with secondary psychotic symptoms (PTSD-SP), PTSD without psychosis, and healthy comparison subjects were compared for differences in cerebrospinal fluid concentrations of corticotropin-releasing factor (CRF) and somatotropin-release-inhibiting hormone (SRIF). RESULTS: The PTSD-SP subjects had significantly higher mean levels of CRF than either the PTSD or control subjects (p <.01). The three groups showed similar SRIF levels. CONCLUSIONS: These data implicate abnormalities in the secretion of CRF with the production of secondary psychotic symptoms in PTSD. This finding supports the validity of PTSD-SP as a PTSD subtype and as a severe form of PTSD.     

Generalized anxiety disorder within the course of major depressive disorder: examining the utility of the DSM‐IV hierarchy rule

Background: The current Diagnostic and Statistical Manual of Mental Disorders (DSM‐IV‐TR) specifies that generalized anxiety disorder (GAD) should not be diagnosed if it occurs exclusively during an episode of a major depressive disorder (MDD) or another mood disorder. This hierarchy rule was intended to promote diagnostic parsimony, but may result in the loss of important clinical information. The goal of this study was to compare individuals with MDD, comorbid MDD and GAD, and GAD within the course of MDD at intake and 12‐month follow‐up on self‐report measures, clinician ratings, and rates of comorbidity. Methods: Participants were divided into three diagnostic groups: MDD without GAD (n=124), comorbid MDD and GAD (n=59), and GAD within the course of MDD (n=166). All the participants completed a semi‐structured clinical interview and self‐report measures assessing psychopathology, temperament, and functional impairment. A subset of the total sample completed a follow‐up assessment of 12 months postintake. Results: Individuals with comorbid MDD and GAD and GAD within the course of MDD reported more psychopathology, negative affect, and functional impairment at intake than individuals with MDD only. The presence of GAD at intake, however, did not differentially predict symptom severity, functional impairment, or the presence of comorbidity at 12‐month follow‐up. Conclusions: Cross‐sectional findings indicate that individuals with GAD within the course of MDD experience levels of psychopathology, functional impairment, and comorbidity similar to those found in individuals with comorbid GAD and MDD. Preliminary longitudinal findings, however, suggest that the presence of GAD in patients with MDD does not have prognostic significance. Depression and Anxiety, 2009. © 2009 Wiley‐Liss, Inc.     

Trauma and posttraumatic stress disorder in treatment-resistant obsessive-compulsive disorder

Prior research has indicated a seemingly unique relation between obsessive-compulsive disorder (OCD) and posttraumatic stress disorder (PTSD) that appears to relate to negative treatment outcome for OCD. However, to date, the prevalence of trauma and PTSD in individuals seeking treatment for OCD is unclear. To begin to address this gap, this study assessed history of traumatic experiences and current PTSD in individuals seeking treatment for treatment-resistant OCD. Trauma predictors of PTSD severity also were examined in this sample. Participants included 104 individuals diagnosed with treatment-resistant OCD who sought treatment over the course of 1 year from OCD specialty treatment facilities. Data were collected via naturalistic retrospective chart reviews of pre-treatment clinical intake files. Findings revealed that 82% of participants reported a history of trauma. Over 39% of the overall sample met criteria for PTSD, whereas almost 50% of individuals with a trauma history met criteria for PTSD. Interpersonal traumas and greater frequency of traumas were most predictive of PTSD severity, and individuals diagnosed with OCD and additional major depressive disorder (MDD) or borderline personality disorder (BPD) appeared at particular risk for a comorbid PTSD diagnosis. PTSD may be relatively common in individuals diagnosed with treatment-resistant OCD; and interpersonal traumas, MDD, and BPD may play a relatively strong predictive role in PTSD diagnosis and severity in such OCD patients.     

Cognitive processes of generalized anxiety disorder in comorbid generalized anxiety disorder and major depressive disorder

This study examines how cognitive variables, which play a central role in the development and maintenance of generalized anxiety disorder (GAD), manifest themselves when GAD and major depressive disorder (MDD) are comorbid. Thirty-two participants were divided into two groups, a group of individuals with a principal diagnosis of comorbid GAD and MDD and a group of people with a principal diagnosis of GAD without MDD. Groups were compared using four cognitive variables: intolerance of uncertainty, poor problem orientation, cognitive avoidance, and beliefs about worry. Our results show that the group of individuals with a principal diagnosis of comorbid GAD and MDD were more intolerant of uncertainty, presented poorer problem orientation, and displayed more cognitive avoidance. The cognitive implications of these results are discussed, and diagnostic criteria are presented to facilitate the differential diagnosis between both groups.     

The International Study to Predict Optimized Treatment in Depression (iSPOT-D): Outcomes from the acute phase of antidepressant treatment

We aimed to characterize a large international cohort of outpatients with MDD within a practical trial design, in order to identify clinically useful predictors of outcomes with three common antidepressant medications in acute-phase treatment of major depressive disorder (MDD). The international Study to Predict Optimized Treatment in Depression has presently enrolled 1008 treatment-seeking outpatients (18–65 years old) at 17 sites (five countries). At pre-treatment, we characterized participants by symptoms, clinical history, functional status and comorbidity. Participants were randomized to receive escitalopram, sertraline or venlafaxine-extended release and managed by their physician following usual treatment practices. Symptoms, function, quality of life, and side-effect outcomes were assessed 8 weeks later. The relationship of anxiety to response and remission was assessed by comorbid Axis I diagnosis, presence/absence of anxiety symptoms, and dimensionally by anxiety symptom severity. The sample had moderate-to-severe symptoms, but substantial comorbidity and functional impairment. Of completers at week 8, 62.2% responded and 45.4% reached remission on the 17-item Hamilton Rating Scale for Depression; 53.3% and 37.6%, respectively on the 16-item Quick Inventory of Depressive Symptoms. Functional improvements were seen across all domains. Most participants had side effects that occurred with a frequency of 25% or less and were reported as being in the “none” to minimal/mild range for intensity and burden.Outcomes did not differ across medication groups. More severe anxiety symptoms at pre-treatment were associated with lower remission rates across all medications, independent of depressive severity, diagnostic comorbidity or side effects. Across medications, we found consistent and similar improvements in symptoms and function, and a dimensional prognostic effect of comorbid anxiety symptoms. These equivalent outcomes across treatments lay the foundation for identifying potential neurobiological and genetic predictors of treatment outcome in this sample.     

Psychotic features and combat-associated PTSD

Psychotic symptoms and psychotic disorder diagnoses have occasionally been reported in association with chronic posttraumatic stress disorder (PTSD). Although psychotic features may be related to core PTSD symptoms, i.e., part of the reexperiencing phenomena, it is possible that they are secondary to certain comorbid disorders which are also prevalent in this patient population, e.g., major depression or substance abuse. In a prospective study, combat associated PTSD patients (n = 25) were administered clinical ratings, including the Structured Clinical Interview for DSM-III-R with psychotic screen (SCID-P), Clinician Administered PTSD Scale (CAPS) and the Impact of Events Scale (IES). Thirty-six percent (n = 9) endorsed psychotic symptoms with associated comorbidity including: major depressive episode, bipolar disorder, alcohol or polysubstance abuse panic disorder, and phobias. All but one of the patients with psychotic features also met criteria for major depressive episode. None had a primary psychotic disorder diagnosis. There were no significant differences in total CAPS scores between patients with or without psychotic features (82.6 ± 17.6 versus 75.3 ± 22.4, p ns), nor for the different symptom cluster subscales. There were also no differences in the IES scores between groups (34.8 ± 10 versus 32.6 ± 10 p ns). This suggests that these psychotic features may not necessarily reflect severity of PTSD symptoms. PTSD may share a common diathesis with mood disorders including psychotic depression. Further study is needed of these phenomena. Depression and Anxiety 5:34–38, 1997. © 1997 Wiley-Liss, Inc.     

Prevalence and features of generalized anxiety disorder in Department of Veteran Affairs primary care settings

Generalized anxiety disorder (GAD) is a highly prevalent distressing condition for individuals in both community and community primary care settings. However, despite the high prevalence of GAD identified in epidemiological studies, little is known about GAD and its related symptoms and impairments in veteran populations. The present study investigated the prevalence, comorbidity, physical and mental health impairment, and healthcare utilization of veteran participants with GAD, as well as comparing symptoms of GAD and posttraumatic stress disorder (PTSD). Veterans (N=884) participated in a cross-sectional investigation in primary care clinics in four Veteran Affairs Medical Centers (VAMCs) and completed diagnostic interviews and self-report questionnaires; a chart review was conducted to assess their VAMC healthcare utilization. A large number of participants (12%) met diagnostic criteria for GAD, reporting significantly worse emotional health, pain, and general health, in addition to increased mental healthcare utilization and antidepressant medications. In addition, GAD was found in 40% of participants with PTSD, resulting in more severe symptoms and impairment than in patients with GAD alone. These findings provide evidence of high prevalence and severe impairment associated with GAD in veterans and highlight the need for improved recognition, assessment, and treatments for GAD.     

Untangling the psychiatric comorbidity of posttraumatic stress disorder in a sample of flood survivors

This report empirically examines multiple explanations for the high rates of psychiatric comorbidity seen with posttraumatic stress disorder (PTSD). One hundred sixty-two St. Louis area survivors of the 1993 Great Midwest Floods were interviewed a few months after the flood subsided using the Diagnostic Interview Schedule (DIS) and its Disaster Supplement to assess psychiatric history relative to PTSD and five other psychiatric disorders. Thirty-five subjects (23%) met criteria for PTSD related to the flood. PTSD was frequently comorbid with other disorders. Seventeen subjects (10%) developed a new, non-PTSD psychiatric disorder after the flood. New non-PTSD disorders were rare in the absence of PTSD symptoms. Though prior psychiatric history was predictive of developing PTSD, no support was found that prior psychiatric history contributed to PTSD through social vulnerability. Thus, support was found for a model in which PTSD contributes to the development of other disorders following trauma, whereas no evidence was found to suggest that comorbid disorders develop independently of PTSD following trauma, or that comorbidity was due to symptom overlap among disorders. The lack of support for models in which psychosocial resources mediate the effect of psychiatric history on the development of PTSD indirectly confirms models of physiological vulnerability to PTSD development.