Diagnosing mental disorders in the community. A difference that matters?

Abstract

Brugha and his colleagues in this issue raise important questions about the validity of standardized diagnostic interviews of mental disorders, such as the Composite International Diagnostic Interview (CIDI) (WHO, 1990). Although their concerns refer predominantly to the use of such instruments in epidemiological research, the authors' conclusions also have significant implications for diagnostic assessments in clinical practice and research. We agree with Brugha et al. that the inflexible approach to questioning used in standardized interviews can lead to an increased risk of invalidity with regard to some diagnoses. We also agree that the use of more semi-structured clinical questions has the potential to address this problem. However, we disagree with Brugha et al. in several other respects.First, we disagree with the authors' initial exclusive emphasis on diagnosis with regard to need assessment and consequences for the allocation of service resources. It is becoming increasingly clear that knowledge about diagnosis does not, in itself, whether assessed by clinical or non-clinical diagnostic interviews, provide sufficient information we need for policy purposes and the determination of societal costs, or to judge clinical management guidelines and treatment needs (Regier et al. 1998). Additional, preferably dimensional, data on associated disabilities and distress as well as a focused need evaluation for those psychosocial, psychological and drug interventions that characterize modern treatment strategies are also important. It also has become evident that a great many people in the general population carry more than one diagnosis. This ‘co-morbidity’ complicates further such simple equation of diagnosis prevalence with need assessment and policy decisions. Secondly, we disagree with the conclusion of Brugha et al. that the use of a semi-structured clinical interview, like the most current version of the Structured Clinical Assessment for Neuropsychiatry (SCAN), whether in the hands of clinical or non-clinical interviewers, is most closely approximating the ‘clinical gold standard’ and is the most feasible way to correct the problem of disagreement between semi-structured clinical diagnostic interviews and standardized diagnostic interviews. We believe that the practical reliability and validity problems associated with using such a clinical interviewing approach especially in large-scale community surveys as well as in cross-national research more than cancel out any theoretical advantage this approach might have in clarifying meaning. Thirdly, we disagree with the suggestion of Brugha et al. that the problem of validity is inherent in standardized non-clinician interviews. Indeed, as detailed below, there is no evidence that across all diagnoses clinical semi-structured interviews reveal more promising psychometric properties than standardized interviews. Also methodological research shows quite clearly that a substantial number of potential validity problems in standardized interviews can be overcome.

Norms for the mini-mental state examination: adjustment of the cut-off point in population-based studies (evidences from the Bambuí health aging study)

“…Furthermore, it is important to stress that it was not possible to normalize the MMSE scores of the study population, even using the types of transformation more commonly found in the literature such as logarithmic, cubic or quadratic, among others (results not shown). Thus, the use of the mean is not adequate for the MMSE score distribution in the present study 20,21 . Therefore, percentile distribution of the MMSE score seems to be the most adequate option for the study population.…”

From First Drug Use to Drug Dependence Developmental Periods of Risk for Dependence upon Marijuana, Cocaine, and Alcohol

“…This set of limitations has been discussed quite thoroughly in past NCS papers published in the Archives of General Psychiatry and elsewhere (e.g., see Kessler et al 1994Kessler et al , 1997Anthony et al 1994;Warner et al 1995;Kessler and Mroczek 1996;Wittchen 1996;Hasin et al 1997;Pull et al 1997;Lachner et al 1998;Wittchen et al 1999). Here, we would like to add a note of clarification: large-sample epidemiological studies do not provide the same context for studies of reliability and validity as one can create in a smaller sample study where there might be multiple opportunities for repeated assessment and increasingly detailed diagnostic cross-examination.…”

“…Even when the sampled community residents are willing to complete an initial 1-2 h diagnostic assessment, many of them are not willing to repeat the assessment for the purposes of a reliability or validity study. Furthermore, the participants willing to share more of their time and effort for repeat assessments generally may not be regarded as a random or representative sample of all participants, and there is considerable uncertainty about whether resulting reliability and validity estimates actually hold for the population under study (e.g., see Anthony et al 1985;Wittchen et al 1999). For this reason, there are no definitive estimates of reliability or validity of the NCS drug dependence diagnoses that are based on thorough standardized clinical direct examination and re-appraisal of a proper random sample of the NCS participants.…”

“…Nonetheless, at least with respect to the drug dependence syndromes, recent empirical research provides evidence that epidemiologic studies can and do provide generally valid and reliable estimates of the occurrence of these conditions, as well as their corresponding ages of onset (e.g., see Prusoff et al 1988;Langenbucher et al 1994;Shillington et al 1995;Wittchen et al 1989Wittchen et al , 1998Wittchen et al , 1999Shillington and Clapp 2000). In addition, the types of survival analysis we have performed with respect to drug dependence in the present study have many analogs in studies that other research teams have completed with respect to psychiatric disturbances outside the realm of drug dependence (Breslau and Klein 1999;Prescott and Kendler 1999;Horwath and Weissman 2000;Kessler et al 2001).…”

Erhebung von Suizidgedanken bei Jugendlichen: Vergleich zweier Instrumente

“…B. Wittchen, Üstün, Kessler, 1999;Fischer u. Wiswede, 2002). In der Vergangenheit konnte gezeigt werden, dass etwa die Art der Fragen, mit denen in Untersuchungen ein psychopathologisches Konstrukt erhoben wurde, eine deutliche Auswirkung auf die Prävalenzzahlen haben kann (vgl.…”