The prevalence and correlates of adult ADHD in the United States: results from the National Comorbidity Survey Replication.

OBJECTIVE: Despite growing interest in adult attention deficit hyperactivity disorder (ADHD), little is known about its prevalence or correlates. METHOD: A screen for adult ADHD was included in a probability subsample (N=3,199) of 18-44-year-old respondents in the National Comorbidity Survey Replication, a nationally representative household survey that used a lay-administered diagnostic interview to assess a wide range of DSM-IV disorders. Blinded clinical follow-up interviews of adult ADHD were carried out with 154 respondents, oversampling those with positive screen results. Multiple imputation was used to estimate prevalence and correlates of clinician-assessed adult ADHD. RESULTS: The estimated prevalence of current adult ADHD was 4.4%. Significant correlates included being male, previously married, unemployed, and non-Hispanic white. Adult ADHD was highly comorbid with many other DSM-IV disorders assessed in the survey and was associated with substantial role impairment. The majority of cases were untreated, although many individuals had obtained treatment for other comorbid mental and substance-related disorders. CONCLUSIONS: Efforts are needed to increase the detection and treatment of adult ADHD. Research is needed to determine whether effective treatment would reduce the onset, persistence, and severity of disorders that co-occur with adult ADHD.

The prevalence and correlates of nonaffective psychosis in the National Comorbidity Survey Replication (NCS-R).

BACKGROUND: To estimate the prevalence and correlates of clinician-diagnosed DSM-IV nonaffective psychosis (NAP) in a national household survey. METHODS: Data came from the United States National Comorbidity Survey Replication (NCS-R). A screen for NAP was followed by blinded sub-sample clinical reappraisal interviews. Logistic regression was used to impute clinical diagnoses to respondents who were not re-interviewed. The method of Multiple Imputation (MI) was used to estimate prevalence and correlates. RESULTS: Clinician-diagnosed NAP was well predicted by the screen (area under the curve [AUC] = .80). The MI prevalence estimate of NAP (standard error in parentheses) is 5.0 (2.6) per 1000 population lifetime and 3.0 (2.2) per 1000 past 12 months. The vast majority (79.4%) of lifetime and 12-month (63.7%) cases met criteria for other DSM-IV hierarchy-free disorders. Fifty-eight percent of 12-month cases were in treatment, most in the mental health specialty sector. CONCLUSIONS: The screen for NAP in the NCS-R greatly improved on previous epidemiological surveys in reducing false positives, but coding of open-ended screening scale responses was still needed to achieve accurate prediction. The lower prevalence estimate than in total-population incidence studies raises concerns that systematic nonresponse bias causes downward bias in survey prevalence estimates of NAP.

Screening for serious mental illness in the general population.

BACKGROUND: Public Law 102-321 established a block grant for adults with "serious mental illness" (SMI) and required the Substance Abuse and Mental Health Services Administration (SAMHSA) to develop a method to estimate the prevalence of SMI. METHODS: Three SMI screening scales were developed for possible use in the SAMHSA National Household Survey on Drug Abuse: the Composite International Diagnostic Interview Short-Form (CIDI-SF) scale, the K10/K6 nonspecific distress scales, and the World Health Organization Disability Assessment Schedule (WHO-DAS). An enriched convenience sample of 155 respondents was administered all screening scales followed by the 12-month Structured Clinical Interview for DSM-IV and the Global Assessment of Functioning (GAF). We defined SMI as any 12-month DSM-IV disorder, other than a substance use disorder, with a GAF score of less than 60. RESULTS: All screening scales were significantly related to SMI. However, neither the CIDI-SF nor the WHO-DAS improved prediction significantly over the K10 or K6 scales. The area under the receiver operating characteristic curve of SMI was 0.854 for K10 and 0.865 for K6. The most efficient screening scale, K6, had a sensitivity (SE) of 0.36 (0.08) and a specificity of 0.96 (0.02) in predicting SMI. CONCLUSIONS: The brevity and accuracy of the K6 and K10 scales make them attractive screens for SMI. Routine inclusion of either scale in clinical studies would create an important, and heretofore missing, crosswalk between community and clinical epidemiology.

Clinical calibration of DSM-IV diagnoses in the World Mental Health (WMH) version of the World Health Organization (WHO) Composite International Diagnostic Interview (WMHCIDI).

An overview is presented of the rationale, design, and analysis plan for the WMH-CIDI clinical calibration studies. As no clinical gold standard assessment is available for the DSM-IV disorders assessed in the WMH-CIDI, we adopted the goal of calibration rather than validation; that is, we asked whether WMH-CIDI diagnoses are 'consistent' with diagnoses based on a state-of-the-art clinical research diagnostic interview (SCID; Structured Clinical Interview for DSM-IV) rather than whether they are 'correct'. Consistency is evaluated both at the aggregate level (consistency of WMH-CIDI and SCID prevalence estimates) and at the individual level (consistency of WMH-CIDI and SCID diagnostic classifications). Although conventional statistics (sensitivity, specificity, Cohen's kappa) are used to describe diagnostic consistency, an argument is made for considering the area under the receiver operator curve (AUC) to be a more useful general-purpose measure of consistency. In addition, more detailed analyses are used to evaluate consistency on a substantive level. These analyses begin by estimating prediction equations in a clinical calibration subsample, with WMH-CIDI symptom-level data used to predict SCID diagnoses, and using the coefficients from these equations to assign predicted probabilities of SCID diagnoses to each respondent in the remainder of the sample. Substantive analyses then investigate whether estimates of prevalence and associations when based on WMH-CIDI diagnoses are consistent with those based on predicted SCID diagnoses. Multiple imputation is used to adjust estimated standard errors for the imprecision introduced by SCID diagnoses being imputed under a model rather than measured directly. A brief illustration of this approach is presented in comparing the precision of SCID and predicted SCID estimates of prevalence and correlates under varying sample designs.

Validity of pilot Adult ADHD Self- Report Scale (ASRS) to Rate Adult ADHD symptoms.

BACKGROUND: The goal of this study was to validate the pilot Adult ADHD Self-Report Scale (pilot ASRS) versus standard clinician ratings on the ADHD Rating Scale (ADHD RS). METHOD: Sixty adult ADHD patients took the self-administered ADHD RS and then raters administered the standard ADHD RS. Internal consistency of symptom scores was assessed by Cronbach's alpha. Agreement of raters was established by intra-class correlation coefficients (ICCs) between scales. RESULTS: Internal consistency was high for both patient and rater-administered versions (Cronbach's alpha 0.88, 0.89, respectively). The ICC between scales for total scores was also high (0.84); ICCs for subset symptom scores were also high (both 0.83). There was acceptable agreement for individual items (% agreement: 43%-72%) and significant kappa coefficients for all items (p < 0.001). CONCLUSIONS: The pilot Adult ADHD Self-Report Scale symptom checklist is a reliable and valid scale for evaluating ADHD for adults and shows a high internal consistency and high concurrent validity with the rater-administered ADHD RS.

The World Health Organization Adult ADHD Self-Report Scale (ASRS): a short screening scale for use in the general population.

BACKGROUND: A self-report screening scale of adult attention-deficit/hyperactivity disorder (ADHD), the World Health Organization (WHO) Adult ADHD Self-Report Scale (ASRS) was developed in conjunction with revision of the WHO Composite International Diagnostic Interview (CIDI). The current report presents data on concordance of the ASRS and of a short-form ASRS screener with blind clinical diagnoses in a community sample. METHOD: The ASRS includes 18 questions about frequency of recent DSM-IV Criterion A symptoms of adult ADHD. The ASRS screener consists of six out of these 18 questions that were selected based on stepwise logistic regression to optimize concordance with the clinical classification. ASRS responses were compared to blind clinical ratings of DSM-IV adult ADHD in a sample of 154 respondents who previously participated in the US National Comorbidity Survey Replication (NCS-R), oversampling those who reported childhood ADHD and adult persistence. RESULTS: Each ASRS symptom measure was significantly related to the comparable clinical symptom rating, but varied substantially in concordance (Cohen's kappa in the range 0.16-0.81). Optimal scoring to predict clinical syndrome classifications was to sum unweighted dichotomous responses across all 18 ASRS questions. However, because of the wide variation in symptom-level concordance, the unweighted six-question ASRS screener outperformed the unweighted 18-question ASRS in sensitivity (68.7% v. 56.3%), specificity (99.5% v. 98.3%), total classification accuracy (97.9% v. 96.2%), and kappa (0.76 v. 0.58). CONCLUSIONS: Clinical calibration in larger samples might show that a weighted version of the 18-question ASRS outperforms the six-question ASRS screener. Until that time, however, the unweighted screener should be preferred to the full ASRS, both in community surveys and in clinical outreach and case-finding initiatives.