Standardized Diagnostic Interview Research Articles

Recognition of psychiatric disorders in musculoskeletal and cardiovascular rehabilitation patients

Härter M, Woll S, Reuter K, Wunsch A, Bengel J. Recognition of psychiatric disorders in musculoskeletal and cardiovascular rehabilitation patients. Arch Phys Med Rehabil 2004;85:1192–7. Objective To investigate the detection rate of psychiatric disorders in rehabilitation inpatients with musculoskeletal and cardiovascular diseases (CVDs). Design Cross-sectional survey; analysis of medical charts and discharge reports, combined with standardized diagnostic interviews. Setting Four orthopedic and 6 cardiovascular rehabilitation hospitals in southwest Germany. Participants More than 1700 inpatients with different musculoskeletal disorders and CVDs participated in the survey. On the basis of their General Health Questionnaire score, 205 patients with musculoskeletal diseases and 164 patients with CVDs were selected randomly for standardized interviews. Discharge reports of interviewed patients were analyzed. Interventions Not applicable. Main outcome measures Clinical interview (Composite International Diagnostic Interview [CIDI]) to obtain diagnoses of psychiatric disorders as defined by the Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV). Assessment of psychosocial burden and diagnoses of mental disorders, as well as admission to psychologic treatments, based on discharge reports of the attending physicians. Results The detection rate (sensitivity) of mental disorders was 48% in the orthopedic rehabilitation patients and 32% in the cardiovascular patients. Specificity was 80% in musculoskeletal patients and 87% in cardiovascular patients. Differential diagnostic competencies were lacking, and only half of the physicians’ diagnoses corresponded to the CIDI diagnoses. Conclusions The results showed a need for current DSM-IV or International Classification of Diseases, 10th edition, psychodiagnostics in medical rehabilitation to detect mental disorders in patients in the rehabilitation process at an earlier stage and to refer patients with comorbid mental disorders to adequate treatment.

Panic disorders and agoraphobia: side effects of treatment with an implantable cardioverter/defibrillator.

Implantable cardioverter/defibrillator (ICD) treatment has reduced the mortality of patients with a high risk of sudden cardiac death. However, ICD discharges may cause anxiety with respect to new discharges and lead to preventive, for example, phobic, behavior. This study evaluated the frequency of panic disorders and agoraphobia in patients with ICD and assessed the risk factors in their development. Treatment with ICD represents a risk factor in the development of anxiety disorders. Ninety patients with ICD were examined using a standardized lifetime Diagnostic Interview of Psychiatric Syndromes (DIPS). This interview makes it possible to estimate the incidence of panic disorders and agoraphobia. The impact of the severity of the underlying cardiac disease, the number of ICD discharges, and the subjective appraisal of the shock experience on the development of panic disorders and agoraphobia was assessed. Fifteen patients (16.7%) developed anxiety disorders after ICD implantation. The incidence was 21% in patients with and 6.9% in patients without ICD discharge. In patients with two or more ICD discharges annually, the incidence of panic disorders and agoraphobia was higher than that in patients with a single ICD discharge annually (62 vs. 10%, p<0.01). The intensity of self-observation of their body was significantly related to the development of anxiety disorders (p<0.001). Panic disorders and agoraphobia are frequent side effects of ICD treatment. Risk factors in the development of these disorders are two or more ICD discharges annually and a negative cognitive appraisal of ICD discharges. Therapeutic efforts should aim at reducing the number of ICD discharges and provide early psychological treatment.

Mental Disorders in Obese Children and Adolescents

Objective: To evaluate the type and frequency of psychiatric disorders in obese children and adolescents; to assess the correlation between psychopathology and severity of obesity; to explore the relationship between psychiatric disorders in obese children and obesity and psychopathology in their parents. Methods: One hundred fifty-five children referred and followed for obesity were evaluated (98 girls and 57 boys; age, 5 to 17 years). Psychiatric disorders were assessed through a standardized diagnostic interview schedule (K-SADS R) and self-report questionnaires completed by the child (STAIC Trait-anxiety and CDI for depression) or his (her) parents (CBCL or GHQ). These obese children were compared with insulin-dependent diabetic (IDDM) outpatient children (N = 171) on questionnaire data. Results: Eighty-eight obese children obtained a DSM-IV diagnosis, most often an anxiety disorder (N = 63). Psychological disorders were particularly pronounced in those obese children whose parents were disturbed. There was no correlation between severity of obesity in the child or his (her) parents and frequency of psychiatric disorders. Compared with diabetic children, they displayed significantly higher internalized and externalized questionnaire scores and poorer social skills. Conclusion: These results highlight the importance of including a child psychiatric component in the treatment of obesity, which must engage the whole family.

Case-finding for depression in elderly people: balancing ease of administration with validity in varied treatment settings.

Little is known about the performance of brief and ultrabrief (1- and 2-question) depression screens in older patients across varied treatment sites. This study (1) assesses their validity in clinics, hospitals, and nursing homes and (2) assesses cut-points for optimal clinical application. 360 patients aged 60 years and older from 2 urban primary care practices (n = 125), 1 general hospital (n = 150), and 8 nursing homes (n = 85) were assessed using the Yale 1-question screen, the 2-question instrument derived from the Primary Care Evaluation of Mental Disorders, and long and short versions of the Center for Epidemiologic Studies Depression (CES-D) scale and Geriatric Depression Scale (GDS). Sensitivity and specificity were calculated for each screen compared with the criterion standard Diagnostic Interview Schedule (DIS) depression diagnosis and receiver operating characteristic curves generated. 9% of patients met DIS criteria for major depression and 7% for subsyndromal depression. Overall, the 10-item CES-D showed the best sensitivity/specificity for major depression in clinics (79%/81%) and hospitals (92%/77%), and the short GDS in nursing homes (86%/82%). Specificity of 1- and 2-question instruments was generally low. Established cut-points generally worked best for the short screens, while modifications were useful for longer versions. Consideration of site of use is important in selecting brief case-finding instruments for late-life depression, with the 10-item CES-D working best in medical settings and the 15-item GDS in nursing homes.

Natural course and burden of bipolar disorders.

Despite an abundance of older and more recent retrospective and considerably fewer prospective-longitudinal studies in bipolar disorders I and II, there are still remarkable deficits with regard to our knowledge about the natural course and burden. The considerable general and diagnosis-specific challenges posed by the nature of bipolar disorders are specified, highlighting in particular problems in diagnostic and symptom assessment, shifts in diagnostic conventions and the broadening of the diagnostic concept by including bipolar spectrum disorders. As a consequence it still remains difficult to agree on several core features of bipolar disorders, such as when they begin, how many remit spontaneously and how many take a chronic course. On the basis of clinical and epidemiological findings this paper summarizes (i) a significant need to extend the study of the natural course of bipolar disorder in clinical samples beyond the snapshot of acute episodes to the study of the mid-term and long-term symptom course, associated comorbidities and the associated burden of the disease. (ii) In terms of epidemiological studies, that are also of key importance for resolving the critical issues of threshold definitions in the context of the bipolar spectrum concept, there is a clear need for identifying the most relevant risk factors for the first onset and those for the further illness progression in early stages. Since there are some indications that these critical processes might start as early as adolescence, such studies might concentrate on young cohorts and clearly before these prospective patients come to clinical attention. (iii) The value of both types of studies might be enhanced, if beyond the use of standardized diagnostic interview, special attempts are made to use prospective life- and episode-charting methods for bipolar illnesses.

Lack of association between the 5HT 2A receptor polymorphism (T102C) and unipolar affective disorder in a multicentric European study

We report here a case-control association study with T102C polymorphism in the serotonin 2A receptor gene (HTR2A) in patients affected by unipolar affective disorder (UPAD) and in controls. A total of 284 subjects were genotyped (142 UPAD and 142 controls). All subjects were interviewed using standard diagnostic interviews and matched. A homogenous population of unipolar patients with suicidal attempt was identified. Conditional logistic regression was applied. No association of the HTR2A polymorphism was found in the overall sample of 142 UPAD-control pairs regarding allele and genotype frequencies ( P=0.36 and P=0.52 respectively) and homo-heterozygote distributions ( P=0.91). This study confirms, in a multicentric European sample, the earlier observations that the T102C HTR2A polymorphism is not associated with UPAD. Nevertheless, a type 2 statistical error cannot be excluded. Therefore, to exclude the implication of HTR2A in UPAD, this result must be replicated in larger samples and in other populations using the transmission disequilibrium test and different polymorphisms around HTR2A.

Prevalence of pervasive developmental disorders in the British nationwide survey of child mental health

The prevalence of pervasive developmental disorders (PDD) is not well established and needs monitoring. We investigated the prevalence of PDDs in the 1999 nationwide British survey of child and adolescent mental health. A randomized stratified sample of children (n = 12,529) aged 5-15 was generated from Child Benefit Records. Trained interviewers interviewed parents and youths aged 11 or older with a standardized diagnostic interview (Development and Well-Being Assessment) and questionnaire data (Strengths and Difficulties Questionnaire) were obtained from teachers and parents who also completed self-report measures of psychological distress. A team of experienced clinicians using all data sources achieved final diagnostic determination. A total of 10,438 (83%) interviews were conducted. There were two girls with Rett syndrome (weighted prevalence: 3.8/10,000 girls) and 27 children with other PDDs (weighted prevalence: 26.1/10,000). Compared to children with a psychiatric disorder other than PDD, social but not behavioural problems were more frequent in the PDD group. Parents of children with PDDs had higher rates of psychological distress than those from the two comparison groups. Consistent with other recent surveys, PDD rates are higher than those reported 30 years ago. The burden associated with PDDs is very high.

Antenatal screening for postnatal depression: a systematic review.

To describe the screening properties of the antenatal tools which have been developed to predict depression after birth and to summarize the implications of the findings for antenatal screening. Systematic review and secondary analysis of published papers. Sixteen studies including sufficient data for the calculation of screening properties were identified. The majority developed a study-specific screening instrument. Outcome assessments used the Edinburgh Postnatal Depression Scale or standardized diagnostic psychiatric interviews, or both. In the two largest population-based studies, the proportion of women screening as positive ('at risk' of postnatal depression) was 16 and 52%, respectively, and of these only 35 and 8% actually developed depression after birth. No screening instrument(s) met the criteria for routine application in the antenatal period. Factors that may have affected poor sensitivity and positive predictive values include the exclusion of key domains in predicting risk, particularly personality, a past history of abuse and postnatal events, the contribution of which may be being under-estimated in studies evaluating antenatal risk prediction tools.

Are obese adolescents and young adults at higher risk for mental disorders? A community survey.

Associations between body mass index (BMI) and mental disorders meeting Axis-I diagnoses according to the Diagnostic and Statistical Manual for Mental Disorders IV (DSM-IV) were investigated in The Early Developmental Stages of Psychopathology Study in a large population-based sample, which included adolescents and young adults of both genders for the first time. A total of 3021 German subjects ranging from 14 to 24 years of age were assessed for specific DSM-IV diagnoses derived from a modified version of the standardized Composite International Diagnostic Interview, and general psychological disturbances, using the Symptom Checklist-90-Revised. BMI percentiles for age and gender were calculated to avoid systematic bias in the BMI distribution resulting from the young age range represented in the sample. Additionally, subjects with a lifetime diagnosis of any eating disorder were excluded from statistical analysis to control the confounding effect of body weight-related eating disorders on associations between BMI and psychopathology. The results based on logistic regression analyses and MANOVAs demonstrate that the BMI is not associated with mental disorders or general psychopathologies. There were no significant associations between BMI and mood, anxiety, substance, and somatoform disorders, a result that contrasts with almost all previous clinical studies. Additionally, in contrast to clinical investigations and most epidemiological studies, neither obesity nor underweight was significantly associated with any kind of general psychopathology. The overall finding that obesity is not significantly related to marked psychopathology in the general German population of adolescents and young adults has important clinical implications.

Screening for post-traumatic stress disorder in female Veteran’s Affairs patients: validation of the PTSD checklist

We evaluated the screening validity of a self-report measure for post traumatic stress disorder (PTSD), the PTSD Checklist (PCL), in female Veterans Affairs (VA) patients. All women seen for care at the VA Puget Sound Health Care system from October 1996–January 1999 ( n=2,545) were invited to participate in a research interview. Participants ( n=282) completed the 17-item PCL, followed by a gold standard diagnostic interview for PTSD, the Clinician Administered PTSD Scale (CAPS). Thirty-six percent of the participants ( n=100) met CAPS diagnostic criteria for current PTSD. Receiver Operating Characteristic (ROC) analysis was used to evaluate the screening performance of the PCL. The area under the ROC curve was 0.86 (95% CI 0.82–0.90). A PCL score of 38 optimized the performance of the PCL as a screening test (sensitivity 0.79, specificity 0.79). The PCL performed well as a screening measure for the detection of PTSD in female VA patients.

The natural course of DSM-IV somatoform disorders and syndromes among adolescents and young adults: a prospective-longitudinal community study

Objective. Although somatoform disorders are assumed to be chronic clinical conditions, epidemiological knowledge on their natural course based on representative samples is not available. Method. Data come from a prospective epidemiologic study of adolescents and young adults in Munich, Germany. Respondents’ diagnoses ( N = 2548) at baseline and follow-up on average 42 months later are considered. The follow-up incidence, stability as well as selected baseline risk factors (sociodemographics, psychopathology, trauma exposure) for the incidence and stability of somatoform disorders and syndromes are prospectively examined. Diagnostic information was assessed by using the standardized Munich-Composite International Diagnostic Interview (M-CIDI). Results. Over the follow-up period, incidence rate for any of the covered somatoform diagnoses was 25.7%. Stability for the overall group of any somatoform disorder/syndrome was 48%. Female gender, lower social class, the experience of any substance use, anxiety and affective disorder as well as the experience of traumatic sexual and physical threat events predicted new onsets of somatoform conditions, while stability was predicted by being female, prior existing substance use, affective and eating disorders as well as the experience of a serious accident. Conclusions. At least for a substantial proportion of individuals, the overall picture of somatization seems to be relatively stable, but with fluctuation in the symptom picture over time. Being female, the experience of substance use as well as anxiety disorder seem to constitute risk factors for the onset of new somatoform conditions as well as for a stable course over time.

Effects of three types of potentially biasing information on symptom severity judgments for major depressive episode.

Two experiments examined the effects of potentially biasing information on judgments of symptom severity pertaining to the diagnosis of major depressive episode (MDE). In both experiments, clinicians viewed videotapes of two actor-simulated patients responding to questions from a standardized diagnostic interview. In Study 1, an expectancy effect was found for both patients such that prior information about a clear-cut history of depression resulted in lower rated severity of current symptoms. In addition, a halo effect was observed for one patient in Study 1 and both patients in Study 2: Clear-cut depressive nonverbal behavior (DNVB) resulted in greater rated severity for symptoms that should not have been affected (e.g., appetite/weight change, suicidal ideation). Clear-cut versus near-threshold information for the two essential criteria for MDE did not affect subsequent judgments in either study. Implications for diagnostic interviewing are discussed.

Complex segregation analysis of restless legs syndrome provides evidence for an autosomal dominant mode of inheritance in early age at onset families.

A strong familial component of restless legs syndrome (RLS) is known. The objective of this study therefore was to investigate the likely mode of inheritance of RLS. RLS patients and their first-degree relatives were investigated and classified in RLS affected and RLS nonaffected subjects. Assessments were based on direct, personal standardized diagnostic interviews. Complex segregation analysis was performed with the families stratified according to the mean age at onset of the disease within the families. Two hundred thirty-eight RLS patients, 537 first-degree relatives, and 133 spouses were interviewed. Two groups of families were stratified: mean age at onset up to 30 years of age (Group A) and older than 30 years (Group B; p < 0.005). In Group A, segregation analysis strongly favored a single major gene acting autosomal dominant with a multifactorial component. Parameter estimates were 0.003 for the allele frequency, 1.0 for the penetrance, and 0.005 for the phenocopy rate. In Group B, no evidence for a major gene could be elucidated. The segregation pattern found in our families argues for an autosomal allele acting dominantly in RLS families with an early age at onset of symptoms and suggests that RLS is a causative heterogeneous disease.

Bipolar disorders — relation to personality and temperament

Background: This report examines clinical indicators for bipolarity in a cohort of patients suffering from Borderline Personality Disorder (BPD). Methods: The study was conducted in the Cornell-Westchester Hospital, famed for its expertise in BPD. To avoid biasing our sample, we excluded all BPD patients who were active patients in our anxiety and mood disorders program. Through the use of both open clinical interviews and standardized diagnostic interviews (SCID), borderline patients were examined for evidence of bipolarity by five indicators: history of spontaneous mania, history of spontaneous hypomania, bipolar temperaments, pharmacologic response typical of bipolar disorder, and a positive bipolar family history. Results: Depending on the level of bipolar disorder from the most rigorous (mania) to the most ‘soft’ (bipolar family history), between 13 and 81% of borderline patients showed signs of bipolarity. Based on what the emerging literature supports as rigorously defined bipolar spectrum (bipolar I and II), we submit that at least 44% of BPD belong to this spectrum; adding hypomanic switches during antidepressant pharmacotherapy, the rate of bipolarity in BPD reaches 69%. As expected from this formulation, most responded negatively to antidepressants (e.g. hostility and agitation) and positively to mood stabilizers. Limitations: Small sample size and retrospective gathering of data on treatment response. Conclusion: Patients with BPD more often than not exhibit clinically ascertainable evidence for bipolarity and may benefit from known treatments for Bipolar Spectrum Disorders. Large scale, systematic treatment studies with mood stabilizers are indicated.

Parental depression and depression in offspring: evidence for familial characteristics and subtypes?

The objectives of this paper were twofold. First, to evaluate in a community sample the age of onset of major depression in adolescents and young adults with and without parental major depression. Second, to examine whether specific clinical characteristics of major depression in adolescents and young adults are associated with elevated rates of major depression among parents. Baseline and 4-year follow-up data were used from the Early Developmental Stages of Psychopathology Study (EDSP), a prospective-longitudinal community study of adolescents and young adults. Results are based on 470 subjects who completed the follow-up, for whom diagnostic information for both parents was available, and who reported at least one episode of major depression according to DSM-IV-criteria through second follow-up. Diagnostic assessment in respondents was accomplished by using the standardized Munich-Composite International Diagnostic Interview (M-CIDI). Information on major depression in parents was collected as family history information from the respondents, and additionally from M-CIDI diagnostic interviews with parents of the younger cohort. Both recurrence and impairment as clinical characteristics of major depression in adolescents and young adults were associated with elevated rates of major depression among parents. Age of onset as well as overall higher impairment as clinical characteristics of major depression in youth were associated with elevated rates of parental major depression in the univariate, but not in the multiple, analyses. Our findings suggest that clinical features of major depression may indicate familial subtypes of the disorder, most evident for recurrence and impairment.

Estimating the prevalence of mental and somatic disorders in the community: aims and methods of the German National Health Interview and Examination Survey.

This paper outlines the principal aims and design of the German National Health Interview and Examination Survey, mental health supplement (GHS-MHS), the first nationwide, epidemiological study of both somatic and mental health in Germany on a representative sample of 4,181 subjects in the community. Both the broader context of the study--in particular its methodological relation to the social and somatic core survey of the German National Health Interview and Examination Survey (GHS-CS)--and the internal methodology of the mental health supplement (GHS-MHS) are presented. The study's strategies and method are derived from a consideration of important theoretical issues arising from epidemiological studies in the field of public health. The main instrument used to assess diagnoses of mental disorders was a standardized diagnostic interview for mental disorders (following DSM-IV (CIDI)) applied by clinically trained interviewers. This diagnostic interview was supplemented by modules on comorbidity, help seeking, treatment and impairment. Somatic health diagnoses were made using an integrated approach including self-report measures, a standardized clinical interview, and laboratory measures. Findings on sampling, response rate, weighting and sample characteristics are presented. Critical issues are discussed, including the scientific objectives that have been achieved by the study. Overall, the GHS core survey and its mental health supplement provide the mental health research community with complex data that allow for high-quality analysis of mental disorders and associations with somatic disorders.

Neonatal resuscitation at the borderline of viability

Background: This report examines clinical indicators for bipolarity in a cohort of patients suffering from Borderline Personality Disorder (BPD). Methods: The study was conducted in the Cornell-Westchester Hospital, famed for its expertise in BPD. To avoid biasing our sample, we excluded all BPD patients who were active patients in our anxiety and mood disorders program. Through the use of both open clinical interviews and standardized diagnostic interviews (SCID), borderline patients were examined for evidence of bipolarity by five indicators: history of spontaneous mania, history of spontaneous hypomania, bipolar temperaments, pharmacologic response typical of bipolar disorder, and a positive bipolar family history. Results: Depending on the level of bipolar disorder from the most rigorous (mania) to the most ‘soft’ (bipolar family history), between 13 and 81% of borderline patients showed signs of bipolarity. Based on what the emerging literature supports as rigorously defined bipolar spectrum (bipolar I and II), we submit that at least 44% of BPD belong to this spectrum; adding hypomanic switches during antidepressant pharmacotherapy, the rate of bipolarity in BPD reaches 69%. As expected from this formulation, most responded negatively to antidepressants (e.g. hostility and agitation) and positively to mood stabilizers. Limitations: Small sample size and retrospective gathering of data on treatment response. Conclusion: Patients with BPD more often than not exhibit clinically ascertainable evidence for bipolarity and may benefit from known treatments for Bipolar Spectrum Disorders. Large scale, systematic treatment studies with mood stabilizers are indicated.

Do patients with borderline personality disorder belong to the bipolar spectrum?

Background: This report examines clinical indicators for bipolarity in a cohort of patients suffering from Borderline Personality Disorder (BPD). Methods: The study was conducted in the Cornell-Westchester Hospital, famed for its expertise in BPD. To avoid biasing our sample, we excluded all BPD patients who were active patients in our anxiety and mood disorders program. Through the use of both open clinical interviews and standardized diagnostic interviews (SCID), borderline patients were examined for evidence of bipolarity by five indicators: history of spontaneous mania, history of spontaneous hypomania, bipolar temperaments, pharmacologic response typical of bipolar disorder, and a positive bipolar family history. Results: Depending on the level of bipolar disorder from the most rigorous (mania) to the most ‘soft’ (bipolar family history), between 13 and 81% of borderline patients showed signs of bipolarity. Based on what the emerging literature supports as rigorously defined bipolar spectrum (bipolar I and II), we submit that at least 44% of BPD belong to this spectrum; adding hypomanic switches during antidepressant pharmacotherapy, the rate of bipolarity in BPD reaches 69%. As expected from this formulation, most responded negatively to antidepressants (e.g. hostility and agitation) and positively to mood stabilizers. Limitations: Small sample size and retrospective gathering of data on treatment response. Conclusion: Patients with BPD more often than not exhibit clinically ascertainable evidence for bipolarity and may benefit from known treatments for Bipolar Spectrum Disorders. Large scale, systematic treatment studies with mood stabilizers are indicated.

Trauma and Posttraumatic Stress Disorder in Primary Care Patients.

BACKGROUND: This article examines the nature of psychological trauma and posttraumatic stress disorder (PTSD) in 504 patients recruited from primary care settings. METHOD: Patients were screened for anxiety in waiting rooms at 14 general medical settings, and those with a sufficient number and severity of anxiety symptoms were administered a standardized diagnostic clinical interview. Those who met DSM-IV criteria for an anxiety disorder and who were willing to participate were included in this study. Of the 504 patients, 185 met DSM-IV criteria for PTSD. RESULTS: Results indicated that 418 (83%) of primary care patients in our sample reported at least 1 traumatic event in their lifetime. The most prevalent traumas experienced by the entire sample of participants were witnessing others being seriously injured or killed, serious accidents, and rape. Of those participants with PTSD, rape was the strongest predictor of a PTSD diagnosis. Analyses examining gender differences indicated that, for women, a history of other unwanted sexual contact or witnessing a sexual assault, being attacked with a weapon or with intent to kill, or witnessing someone being injured were found to be risk factors for a PTSD diagnosis. Examination of clinical characteristics indicated a high rate of comorbidity of psychiatric disorders among patients with PTSD, including high rates of alcohol/substance abuse, depression, and suicide attempts. CONCLUSION: These findings emphasize the continued need to assess patients presenting at general medical facilities about trauma history.

Prevalence of Pervasive Developmental Disorders in the British Nationwide Survey of Child Mental Health

The prevalence of pervasive developmental disorders (PDD) is not well established and needs monitoring. The prevalence of PDD in the 1999 nationwide British survey of child and adolescent mental health was investigated. A randomized, stratified sample of children (N= 12,529) aged 5 to 15 years was generated from the Child Benefit Register. Trained interviewers interviewed parents and youths aged 11 or older with a standardized diagnostic interview (Development and Well-Being Assessment), and questionnaire data (Strengths and Difficulties Questionnaire) were obtained from teachers and parents, who also completed self-report measures of psychological distress. Final diagnostic determination was achieved by a team of experienced clinicians using all data sources. A total of 10,438 (83%) interviews were conducted. There were 2 girls with Rett syndrome (weighted prevalence: 3.8/10,000 girls) and 27 children with other PDD (weighted prevalence: 26.1/10,000). Compared with children with a psychiatric disorder other than PDD, social but not behavioral problems were more frequent in the PDD group. Parents of children with PDD had higher rates of psychological distress than those from the two comparison groups. Consistent with other recent surveys, PDD rates are higher than those reported 30 years ago. The burden associated with PDD is very high.