Screening for disease, psychological testing, and psychotherapy Looking behind the mirror.

Abstract

Byline: T. Sathyanarayana Rao, Chittaranjan. Andrade In this issue of the Journal, Berger [sup][1] presents his personal viewpoint on matters related to screening for future disease in the population, use of psychological tests for clinical purposes, and the limitations of psychotherapy as a clinical intervention. All the issues raised are important, and in this editorial we consider additional theoretical and practical matters that arise from the points that he makes. Screening for Future Disease Berger [sup][1] describes the results in New York of screening for Krabbe disease, an inborn error of metabolism. Only 24 babies tested positive out of about a million tested. Of these, 4 developed clinical features of the disease. Two of the 4 children died (one, of treatment complications) and the other 2 showed poor outcomes despite treatment. Parents of the children who tested positive were emotionally traumatized by the test results. So, was the screening cost-effective and did it serve the purpose? It appears not. Screening for disease in the population should serve a purpose. [sup][2] For example, the use of mammograms or cervical smears can identify breast or cervical cancer sufficiently early for intervention to increase life expectancy. Or, a negative test for Huntington's disease in a family member of an affected patient can offer immense relief whereas a positive test, while generating stress, would at least allow the individual the opportunity to plan for his future. Leave alone the risk of future disease, screening for early disease in medical contexts is itself not without controversy. Take women's health, for example. Benefits as well as harms have been described in relation to breast cancer screening; [sup][3] this is because no screening instrument is perfect, and false negatives and false positives (especially the latter, because they are more common) result in unnecessary interventions that are emotionally and physically damaging. A crude estimate obtained from available data suggests that, for every case of breast cancer mortality prevented, approximately, three women would have been unnecessarily identified and treated. [sup][3] Whereas, the outcome would be good for the one life saved, it would be traumatic for the remaining 3 women. With regard to men's health, prostate specific antigen screening has resulted in similar difficulties: There is no consensus that screening has improved survival, and there is no consensus on even whether or not screening should be performed. [sup][4] Unfortunately, there are no screening tests in psychiatry that reliably predict future disease. Indeed, the presence of the APOE epsilon 4 allele increases the risk of Alzheimer's disease, [sup][5] but the sensitivity, specificity, positive predictive value, and negative predictive value of this biological marker are too poor for screening for this allele to be of practical value. [sup][6] The same holds true for genes such as neuregulin, [sup][7] presenilin, [sup][8] dysbindin, [sup][9] DISC1, [sup][10] COMT, [sup][11] and others that have been found to be associated with schizophrenia. The situation is no different for other psychiatric conditions. At the moment, therefore, there does not seem to be hope for effective screening for future disease in psychiatry. The use of Psychological Testing for Diagnosis Berger describes the emergence of depression with suicidal ideation in an 8-year-old son of a woman with a history of major depression; neither family dynamics nor school issues could explain the child's depression. On the one hand, the positive family history notwithstanding, it is uncommon for clinical depression to emerge in one so young; so, a case might be made for psychological testing and probing for hidden sources of stress. On the other hand, given the apparent severity of the phenomenology in the child and the atheoretical nature of the current diagnostic systems (which dictate diagnosis based on phenomenology alone), surely immediate intervention was indicated, even if only of a psychological nature. …