Factor Structure Of Symptoms Research Articles

Identifying symptom clusters during the menopausal transition: observations from the Seattle Midlife Women's Health Study

Objectives First, to explore the variability in how symptoms clustered together over the late reproductive stage, early and late menopausal transition (MT) stages, and early postmenopause; second, to determine whether the symptom factor structure of the preceding MT stage would predict the symptom factor structure of the MT stage immediately following.Methods The sample consisted of a subset of Seattle Midlife Women’s Health Study participants who were in late reproductive or early or late menopausal transition stages or early postmenopause and provided self-reported data on symptoms experienced between 1990 and 2005. Principal components analysis was used to determine how symptoms clustered together across the stages. Variables predicting the symptom factor structure were analyzed by multiple regression.Results Principal components analysis with varimax rotation revealed different factor structures for each of the four stages. The three-factor solution in the late reproductive stage explained a total of 54.9% of the variance. The four-factor solutions in the early and late menopausal transition stages and postmenopause explained a total of 56.5%, 59.3%, and 60.7%, respectively.Conclusions This analysis revealed similar factor structures across the four stages in that each stage revealed a mood component, a vasomotor component, and a pain component. However, the symptoms differed somewhat in how they grouped from stage to stage. Regression analysis demonstrated that a relationship exists between the symptom factor structures across stages. Controlling for demographic and lifestyle variables, it was revealed that the symptom clusters at the early and late menopausal transition stages and early postmenopause were best predicted by the symptom factor structure of the previous stage.

Numbing and Dysphoria Symptoms of Posttraumatic Stress Disorder Among Iraq and Afghanistan War Veterans

Iraq and Afghanistan war veterans experience significant rates of posttraumatic stress disorder (PTSD) and other trauma-related mental health conditions. Understanding how specific PTSD symptomatology affects physical health and psychosocial functioning may be useful in improving the conceptualization of PTSD nosology and informing treatment approaches for this population. Confirmatory factor analytic evidence supports four-factor models of PTSD symptoms that classify emotional numbing and/or dysphoria symptoms as a distinct PTSD symptom cluster, and these symptoms appear to be related to poorer psychological adjustment among returning Iraq and Afghanistan war veterans. This review briefly describes current conceptualizations of numbing/dysphoria symptoms of PTSD and summarizes research on the factor structure of PTSD symptoms. Then, the literature on the influence of numbing/dysphoria symptoms on physical and psychological health among these veterans is reviewed, and implications for treatment and directions for future research are presented.

The factor structure of major depression symptoms: A test of four competing models using the Patient Health Questionnaire-9

Little research has examined the underlying symptom structure of major depressive disorder (MDD) symptoms based on DSM-IV criteria. Our aim was to analyze the symptom structure of major depression, using the Patient Health Questionnaire-9 (PHQ-9). The PHQ-9 was administered to a sample of 2615 Army National Guard soldiers from Ohio. A one-factor model of depression and three separate two-factor models previously established in the literature were evaluated using confirmatory factor analysis. Results demonstrated greater support for the two-factor models of depression than for the one-factor model. The best fitting model was the two-factor model of somatic and non-somatic symptoms supported previously by Krause et al. (2010) and Richardson and Richards (2008). Implications for understanding the components and mechanisms of MDD are discussed.

Evaluation of the factor structure of symptoms in patients with schizophrenia

Considering the widespread use of the Positive and Negative Syndrome Scale (PANSS) and its factors around the world in clinical trials, it is clearly necessary to perform a transcultural validation of the factor structure of the PANSS. The purpose of the present study was to examine the PANSS factor structure in a Korean sample of subjects with schizophrenia. A total of 150 outpatients were assessed using the PANSS and other clinical rating scales. Principal component analyses revealed five factors, i.e., negative, cognitive/disorganization, positive, excitement, and depression/anxiety dimensions, which accounted for 64.1% of the total variance. All five factors showed good internal consistency, suggesting that the reliability of the factors extracted was adequate. Significant correlations were found between the five components of the PANSS and the corresponding clinical rating scales. The results of the present study indicate that the five-factor model best fit the data from our patients and that it was validated transculturally. The factor structures should be further validated using various neurobiological methods to ultimately help in clarifying the heterogeneity and pathogenesis of symptomatology in schizophrenia.

The Factor Structure of Traumatic Stress in Parents of Children With Cancer: A Longitudinal Analysis*

Objectives To determine the factor structure of posttraumatic stress symptoms (PTSS) and assess its stability over time among parents of children diagnosed with cancer. Methods Parents of children with cancer included in a longitudinal study completed the posttraumatic stress disorder (PTSD) Checklist–Civilian Version 2 weeks (n = 249) and 2 (n = 234) and 4 (n = 203) months after their child's diagnosis. Confirmatory factor analysis (CFA) was used to assess 3 models of the underlying dimensions of PTSD and invariance tests were used to assess stability over time. Results A longitudinal CFA with the factors reexperiencing, avoidance, dysphoria, and hyperarousal provided best fit to the data. Invariance testing suggested that the pattern and size of loadings were equivalent across the three assessments. Discussions Findings tentatively suggest that PTSS among parents of children with cancer consist of four factors. Implications for research and clinical practice are discussed.

Delirium in elderly people: a study of a psychiatric liaison service in north India

Very few studies from India have studied the phenomenology of delirium. The aim of the present study was to study the phenomenology as measured using the Delirium Rating Scale-Revised-98 (DRS-R98), the associated etiologies and the outcome of delirium among the elderly participants seen by the consultation-liaison psychiatric service in India. In addition, an attempt was made to study the factor structure of symptoms using principal components analysis. The case notes of 109 elderly patients referred to psychiatry liaison services were reviewed. The mean age of the sample was 73.35 years (SD: 7.44; range 65-95 years) and two-thirds of the sample had hospital emergent delirium. The mean DRS-R98 severity score was 18.77 and the DRS-R98 total score was 24.81. In 15 patients the DRS-R98 scores were in the subsyndromal range. Among the various symptoms present, most patients had sleep-wake cycle disturbance, disturbance in orientation, attention and short-term memory impairments, fluctuation of symptoms, temporal onset of symptoms and a physical disorder. Principal components analysis identified three factors which explained 43.5% of variance of symptomatology and it yielded a three-factor structure. Endocrine/metabolic disturbances were the commonest associated etiological category with delirium. The mean hospital stay after being referred to psychiatry referral services was 8.89 days, after which delirium improved in 58.7% of cases. The mortality rate during the inpatient stay was 16.5%. Results suggest that the symptoms of delirium as assessed by DRS-R98 separate out into a three-factor structure. Delirium is commonly associated with metabolic endocrine disturbances and about one-sixth of the patients die during the short inpatient stay.

Symptoms associated with psychosis risk in an adolescent birth cohort: improving questionnaire utility with a multidimensional approach

Specialized self-report questionnaires have been developed for detection of symptoms indicative of psychosis risk. The identification of at-risk individuals is typically based on sum scores, which assume equal severity and discriminability of all symptoms, and a single dimension of illness. Our aim was to test whether separable dimensions of risk could be identified in the general population. We explored the latent structure of one such questionnaire using full-information item factor analysis, deriving exploratory models from the PROD-Screen questionnaire responses of the adolescent general population based on the Northern Finland 1986 Birth Cohort (n=6611). A three-dimensional factor structure of positive, negative and general symptoms emerged. The factor structure, the appropriateness of the statistical model and the application of the results to the detection of heightened psychosis risk are discussed. In explicitly taking into account the multidimensionality and varying symptom severity of the included items, the current model provides an improvement in questionnaire-based assessment of psychosis risk.

Factor Structure of the PTSD Checklist in a Sample of OEF/OIF Veterans Presenting to Primary Care: Specific and Nonspecific Aspects of Dysphoria.

Although DSM-IV-TR diagnostic criteria for posttraumatic stress disorder (PTSD) include three primary symptom clusters, recent evidence from confirmatory factor analyses suggest that the latent structure of PTSD is better represented by four factors, which will likely be reflected in the upcoming DSM-5. Given this likely transition from three to four clusters, the present study sought to examine specific and non-specific aspects of dysphoria in the factor structure of PTSD symptoms in a sample of OEF/OIF combat veterans presenting to a Veterans Affairs primary care clinic. PTSD symptoms were assessed using the PCL-M (Weathers et al. 1993). Results from confirmatory factor analyses suggested that a dysphoria factor involving a number of non-specific distress symptoms may be an important part of the PTSD symptom profile. After controlling for variance due to general psychological distress, we further found that factor loadings on the dysphoria factor were attenuated but continued to significantly load onto the factor, suggesting that dysphoria may be a specific part of the PTSD symptom constellation.

Symptoms of delirium: an exploratory factor analytic study among referred patients

Objective Factor analytic studies of delirium symptoms among patients referred through consultation–liaison psychiatric services are rare. We examined the factor structure of delirium symptoms in referred patients and determined whether combining items from several delirium rating scales influenced the factor structure of delirium symptoms. Method Eighty-six patients with delirium ( Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision) referred though the consultation–liaison services were assessed with structured rating scales. Nineteen symptom items extracted from the Delirium Rating Scale—Revised-98 (DRS-R-98), the Memorial Delirium Assessment Scale and the Confusional State Evaluation Scale were subjected to an exploratory (principal component) factor analysis. A second such analysis was conducted on 15 items of the DRS-R-98 for comparison. Results Compared with prior studies, patients were younger and the majority had hyperactive delirium. Principal components analysis identified two factors: (1) a “cognitive” factor comprising of disturbances in language, thought processes, orientation, attention, short- and long-term memory, visuospatial ability, consciousness (awareness) and perseveration accounted for 28.9% of the variance and (2) a “behavioral” factor consisting of sleep–wake cycle disturbances, delusions, perceptual disturbances, motor agitation, affect–lability, distractibility, irritability and temporal onset accounted for 18.9% of the variance. An identical factor structure was obtained with the DRS-R-98 items. Conclusions Similar to previous factor analytic studies, the present study supported the existence of two principal dimensions of delirium, cognitive and behavioral. Additionally, it extended the results of earlier investigations to a wider group of patients with delirium, suggesting that these dimensions might provide important clues to the neurobiology of delirium.

Overlap of ADHD and oppositional defiant disorder DSM-IV derived criteria.

One possible reason for being controversies regarding ADHD may be related to the validity and reliability of diagnostic criteria of attention deficit hyperactivity disorder and oppositional defiant disorder. Diagnostic criteria of oppositional defiant disorder include eight symptoms. This study examines the factor structure of oppositional defiant disorder symptoms, its discriminant validity from attention deficit hyperactivity disorder, its convergent validity and internal reliability. Parents of 111 referral children and adolescents with attention deficit hyperactivity disorder completed DSM-IV referenced based attention deficit hyperactivity disorder and oppositional defiant disorder checklists. Factor analysis indicated that the attention deficit hyperactivity disorder symptom of: "often has trouble organizing activities" and "often runs about or climbs when and where it is not appropriate" were a part of the oppositional defiant disorder component. These symptoms less often than other symptoms differentiate attention deficit hyperactivity disorder from oppositional defiant disorder. The convergent validity for oppositional defiant disorder symptoms ranged from 0.64 to 0.79. The parent-rating checklist of oppositional defiant disorder symptoms properly differentiates oppositional defiant disorder from attention deficit hyperactivity disorder. However, two items of the attention deficit hyperactivity disorder were listed as symptoms of oppositional defiant disorder. If the factor loading of the items is to be confirmed in further studies, it might be necessary to revise these symptoms criterion in future editions of DSM-IV diagnostic criteria.

Gender differences in the factor structure of posttraumatic stress disorder symptoms in war-exposed adolescents

DSM-IV's three-factor model of posttraumatic stress disorder (PTSD) is rarely empirically supported, whereas other four-factor models ( King et al., 1998; Simms, Watson, & Doebbeling, 2002) have proven to be better representations of PTSD's latent structure. To date, a clear consensus as to which model provides the best representation of PTSD's underlying dimensions has yet to be reached. The current study investigated whether gender is associated with factor structure differences using the King et al. (1998) model of reexperiencing, avoidance, numbing, and hyperarousal PTSD symptoms. Participants were war-exposed Bosnian secondary/high school boys and girls ( N = 1572) assessed nearly two years after the 1992–1995 Bosnian conflict. Confirmatory factor analytic tests of measurement invariance across PTSD model parameters revealed many significant sex-linked differences. Implications regarding the potential role of gender as a moderator of the King et al. (1998) model's factor structure are discussed.

A factor analytic study of the Delirium Rating Scale-Revised-98 in untreated patients with delirium

Objective Existing factor analytic studies of symptoms of delirium are mostly based on small numbers of patients from specialized settings. This study thus sought to examine the factor structure of symptoms of delirium in a reasonably large sample of untreated patients referred to liaison psychiatric services of a multi-specialty hospital in north India, employing the more commonly used Delirium Rating Scale-Revised Version-1998 (DRS-R-98). Method Patients ( n=151) who met Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision criteria for delirium were assessed with the DRS-R-98 prior to starting treatment with psychotropics. A principal component analysis was carried out to determine the factor structure of the symptoms based on these ratings. Results Unlike previous efforts, patients of this study were relatively younger (mean age 47 years), with mainly hyperactive delirium, and did not have comorbid dementia. Three factors which together explained 47.32 % of variance of symptoms were identified. A “global cognitive” factor including disturbances of orientation, attention, short- and long-term memory, and visuospatial ability accounted for 18.33% of the variance. A “sleep and motor symptoms” factor consisting of sleep–wake cycle disturbances; delusions; and perceptual disturbances including hallucinations, motor-agitation, inverse of motor-retardation, and affect-lability accounted for 16% of the variance. A “thought and language” factor comprising abnormalities in language and thought process, temporal onset, and fluctuation of symptoms explained 13% of the variance. Conclusions Thus, the current factor analysis not only confirmed the presence of three principal symptom dimensions of delirium (found in several previous studies) but also extended these findings to a broader group of patients usually referred to liaison psychiatric services.

Factor structure of posttraumatic stress disorder symptoms in OEF/OIF veterans presenting to a polytrauma clinic.

A significant number of Operation Iraqi Freedom/Operation Enduring Freedom (OEF/OIF) veterans are returning from deployment and presenting to Veterans Health Administration (VHA) polytrauma clinics with elevated rates of posttraumatic stress disorder (PTSD) and mild traumatic brain injury (mTBI). Inherent to the accurate assessment and treatment of this diagnostically complex group of veterans is the assumption that the construct of PTSD is the same in this population as in other trauma groups. To our knowledge, no previous study has examined the structure of PTSD in this relevant and fast-growing population of treatment-seeking OEF/OIF veterans. Evidence suggests that the latent structure of PTSD symptoms is best represented by a four-factor model, rather than the three-factor model found in the current DSM-IV-TR. Thus, we examined the three and four-factor models using the PTSD Check List-Civilian (PCL-C) in a sample of treatment-seeking OEF/OIF veterans seen through a VHA polytrauma clinic. A chart review was conducted for OEF/OIF veterans (N = 361) seen through a VHA outpatient polytrauma clinic from September 2007 through August 2008. Participants completed the PCL-C as part of a comprehensive polytrauma evaluation. Confirmatory factor analyses showed that the DSM-IV-TR three-factor model did not fit the data well. A direct comparison showed that the four-factor model provided a superior fit relative to the three-factor model. Results extend the generalizability of the four-factor model to OEF/OIF veterans presenting to Veterans Health Administration (VHA) polytrauma clinics.

Confirmatory factor analysis of posttraumatic stress symptoms assessed by the Impact of Event Scale-Revised in Chinese earthquake victims: Examining factor structure and its stability across sex

The current study investigated the factor structure of posttraumatic stress symptoms assessed by the Impact Event Scale-Revised (IES-R) in a large sample of individuals from China who recently experienced a destructive earthquake. The results of the confirmatory factor analysis indicated that a four-factor structure (intrusion, avoidance-numbing, hyperarousal, and sleep disturbance) emerged as the model best fit in total sample, female and male subsamples, respectively. Moreover, multiple-group confirmatory factor analysis further demonstrated that the four-factor model was quite stable across sex. Implication and limitations for the results are discussed.

Disaggregating the Relationship Between Posttraumatic Stress Disorder Symptom Clusters and Chronic Orofacial Pain: Implications for the Prediction of Health Outcomes with PTSD Symptom Clusters

Research has established a significant relationship between posttraumatic stress disorder (PTSD) symptoms and pain; however, very little research has examined the differential role of PTSD symptom clusters on pain outcomes. (a) To confirm the most appropriate PTSD symptom factor structure for an orofacial pain population and (b) to test a model of prediction of pain outcomes with PTSD symptom clusters. The study was a cross-sectional, retrospective case series of 411 female patients with orofacial pain (mean 41.0 years, SD 13.1). A series of structural equation modeling analyses were conducted to examine five competing models of PTSD symptom clusters. Two four-factor models of PTSD symptom clusters fit the data reasonably well, and differing PTSD symptom clusters predicted different components of pain. To increase predictive utility for pain and for a wide range of health disorders, researchers should examine the unique predictive power of PTSD symptom clusters rather than examining a one-factor model of PTSD symptoms.

Assessing the factor structure of posttraumatic stress disorder symptoms in war-exposed youths with and without Criterion A2 endorsement

Posttraumatic stress disorder's (PTSD) tripartite factor structure proposed by the DSM-IV is rarely empirically supported. Other four-factor models ( King et al., 1998; Simms et al., 2002) have proven to better account for PTSD's latent structure; however, results regarding model superiority are conflicting. The current study assessed whether endorsement of PTSD's Criterion A2 would impact on the factorial invariance of the King et al. (1998) model. Participants were 1572 war-exposed Bosnian secondary students who were assessed two years following the 1992–1995 Bosnian conflict. The sample was grouped by those endorsing both parts of the DSM-IV Criterion A (A2 Group) and those endorsing only A1 (Non-A2 Group). The factorial invariance of the King et al. (1998) model was not supported between the A2 vs. Non-A2 Groups; rather, the groups significantly differed on all model parameters. The impact of removing A2 on the factor structure of King et al. (1998) PTSD model is discussed in light of the proposed removal of Criterion A2 for the DSM-V.

Factor Structure and Predictive Validity of Somatic and Nonsomatic Symptoms From the Patient Health Questionnaire-9: A Longitudinal Study After Spinal Cord Injury

Krause JS, Reed KS, McArdle JJ. Factor structure and predictive validity of somatic and nonsomatic symptoms from the Patient Health Questionnaire-9: a longitudinal study after spinal cord injury. Objective To investigate the factor structure and predictive validity of somatic and nonsomatic depressive symptoms over the first 2.5 years after spinal cord injury (SCI) using the Patient Health Questionnaire-9 (PHQ-9). Design Somatic and nonsomatic symptoms were assessed at baseline during inpatient hospitalization (average of 50 days after onset) and during 2 follow-ups (average of 498 and 874 days after onset). Setting Data were collected at a specialty hospital in the Southeastern United States and analyzed at a medical university. We performed time-lag regression between inpatient baseline and follow-up somatic and nonsomatic latent factors of the PHQ-9. Participants Adults with traumatic SCI (N=584) entered the study during inpatient rehabilitation. Interventions Not applicable. Main Outcome Measure PHQ-9, a 9-item measure of depressive symptoms. Results The inpatient baseline nonsomatic latent factor was significantly predictive of the nonsomatic ( r=.40; P=.000) and somatic latent factors at the second follow-up ( r=.29; P=.006), whereas the somatic factor at inpatient baseline did not significantly predict either factor. In contrast, when regressing latent factors between the 2 follow-ups, the nonsomatic factor predicted only the nonsomatic factor ( r=.66; P=.002), and the somatic factor predicted only future somatic symptoms ( r=.66; P=.000). In addition, the factor structure was not stable over time. Item analysis verified the instability of somatic items between inpatient baseline and follow-up and also indicated that self-harm at inpatient baseline was highly predictive of future self-harm. Conclusions Nonsomatic symptoms are better predictors of future depressive symptoms when first assessed during inpatient rehabilitation, whereas somatic symptoms become stable predictors only after inpatient rehabilitation. Self-harm (suicidal ideation) is the most stable symptom over time. Clinicians should routinely assess for suicidal ideation and use nonsomatic symptoms when performing assessments during inpatient rehabilitation.

Positive psychosis symptom structure in the general population: Assessing dimensional consistency and continuity from “pathology” to “normality”

The current study assessed the dimensionality of positive psychosis symptoms. Data from the National Comorbidity Survey (1990–1992) was used to examine the underlying factor structure of positive psychosis symptoms based on participants’ responses to the 13 Composite International Diagnostic Interview (CIDI) psychosis screening items. Confirmatory factor analysis (CFA) was used to compare four theoretically based competing factor analytic models of positive psychosis. Fit statistics indicated that the best fitting model was comprised of three correlated factors: a hallucinations factor, a Schneiderian delusions factor, and a paranoid delusions factor. There were no significant differences between the sexes on scores for the Schneiderian Delusions and Paranoid dimensions; however, females scored significantly higher on the Hallucinations dimension. At an item level, male respondents were significantly more likely to report experiences of paranoia; being controlled by an external force; and having their thoughts stolen by another. Females, on the other hand, were significantly more likely to experience auditory, olfactory, and tactile hallucinations. They were also more likely to believe that others were reading their mind. The three underlying factors were consistent with existing clinical models of positive psychosis symptom dimensionality and provide further evidence of a continuum of psychosis.

Posttraumatic Stress Disorder Symptom Structure in Injured Children: Functional Impairment and Depression Symptoms in a Confirmatory Factor Analysis

To examine the factor structure of posttraumatic stress disorder (PTSD) symptoms in children and adolescents who have experienced an acute single-incident trauma, associations between PTSD symptom clusters and functional impairment, and the specificity of PTSD symptoms in relation to depression and general distress. Examined PTSD symptom structure in two samples of children (8 to 17 years of age) assessed an average of 6 months after unintentional injury: (1) a combined dataset of 479 children assessed with a PTSD symptom checklist, and (2) a sample of 204 children assessed via a standardized clinical interview. We evaluated the fit of six alternative models for the factor structure of PTSD symptoms, and the association of PTS symptom clusters with indicators of functional impairment. We then evaluated three models for the structure of PTSD and depression symptoms jointly, to examine specificity of PTSD versus general distress or mood symptoms. In both samples, the DSM-IV 3-factor model fit the data reasonably well. Two alternative four-factor models fit the data very well: one that separates effortful avoidance from emotional numbing, and one that separates PTSD-specific symptoms from general emotional distress. Effortful avoidance and dysphoria symptoms were most consistently associated with impairment. The best-fitting model for PTSD and depression symptom clusters had three factors: PTSD-specific, depression-specific, and general dysphoria symptoms. The DSM-IV model for PTSD symptom categories was a reasonable fit for these child data, but several alternative models fit equally well or better, and suggest potential improvements to the current diagnostic criteria for PTSD in children.

Factor structure of posttraumatic stress disorder symptoms in the Australian general population

The tripartite model of posttraumatic stress disorder (PTSD) articulated in DSM-IV has received limited empirical support. Over the past decade, a burgeoning literature on PTSD symptom structure has accumulated suggesting several alternative models. Elucidating the latent structure of PTSD has important clinical and theoretical implications. This paper presents the first confirmatory factor analytic investigation of PTSD symptoms in an epidemiologically based trauma-exposed sample from Australia. Data from a subsample of respondents from the 2007 National Survey of Mental Health and Wellbeing (NSMHWB; n = 2677) were submitted to confirmatory factor analysis and several alternative conceptual models were tested. Empirical support was found for an intercorrelated four-factor model reflecting re-experiencing, avoidance, dysphoria, and hyperarousal symptoms. Given that the DSM is currently under revision, research addressing structural validity concerns is especially timely. The present findings renew calls in the structural literature suggesting that the structure of PTSD should be revised in DSM-V.