The impact of classification on psychopharmacology and biological psychiatry

Herman M. van Praag,

The introduction of modern classification systems of psychiatric diseases (Diagnostic and Statistical Manual of Mental Disorders– III and IV [DSM-III/IV] and International Classification of Diseases, 10th revision [ICD-10]) has brought about enormous progress in psychiatry. For the first time, the various psychiatric schools were able to speak a common language, allowing the comparison of psychiatric patients in different parts of the world. However, this categorical approach is in urgent need of revision, in order to incorporate dimensional aspects such as the transnosological approach, which takes greater account of biological abnormalities. This “state-of-the-art” article reviews both the current situation and future needs.

Conceptualization of the liability for schizophrenia: clinical implications

Ming T. Tsuang, on pages 153 to 164

Definitive knowledge about the pathogenesis of schizophrenia remains elusive in spite of dramatic advances in molecular biology techniques. Molecular genetic studies, in particular, have yielded many promising results. However, there is an increasing discrepancy between current classification systems (DSM-III/IV and ICD-10), on which these studies were based, and recent discoveries in the genetics of schizophrenia, which begs for a broader conceptual outlook. The concept of “schizotaxia” advocated by Ming Tsuang exemplifies this new approach.

Psychostimulants in the therapy of treatment-resistant depression. Review of the literature and findings from a retrospective study in 65 depressed patients

Gabriele Stotz, Brigitte Woggon, Jules Angst, on pages 165 to 174

Treatment-resistant depression is a major challenge in psychiatry. The antidepressants usually prescribed are often not effective at all, making it necessary to experiment with new treatment approaches like combination therapy. An unusual solution relating to psychostimulants is presented here. Evidence that the dopaminergic system plays a role in depression may enhance the value of such a strategy in the future, particularly in view of the lack of dopaminergic antidepressants.

The therapeutic transnosological use of psychotropic drugs

Manfred Ackenheil, Lazara Karelia Montané Jaime, on pages 175 to 181

Current pharmacological treatment, especially in drug trials, is nosology-oriented, as a consequence of the requirements stemming from regulatory authorities. This, however, is at variance with the “endogenous” nature of psychiatric disorders, which, similar to somatic medicine, are likely to result from different causes, thus requiring different types of therapy. This explains why patients are frequently treated in a different way in clinical practice than in trials. Conversely, differing nosological categories may be treated with the same class of psychotropic drugs. All this has theoretical and practical implications regarding our concepts in psychiatry, chief among which is the future need to treat psychiatric patients according to the same principles as in other disciplines of medicine.

Validity of nosological classification

Petr Smolik, on pages 185 to 190

This paper uses the example of schizophrenia to look at the pros and cons of expert clinician diagnosis, based on a holistic approach, in comparison with algorithmic diagnosis, based on the DSM-IV and ICD-10 classification systems. The author highlights the poor correlation between the two types of diagnostic processes, and points out the low validity and limitations of the DSM-IV and ICD-10 classifications.

Diagnostic classification of psychiatric disorders and familial-genetic research

Wolfgang Maier on pages 191 to 196

In principle, specific phenotypes should aggregate in families with high vulnerability to a particular disorder. However, the relevance of the boundaries between the different psychiatric disorders, according to the ICD-10 or DSM-IV, as well as that of comorbidity, is still unclear. The author looks at these issues from the point of view of genetic epidemiological studies of schizophrenia, and highlights the discrepancy between the range of phenotypes transmitted in families of schizophrenics and the current diagnostic boundaries. Progress in familialgenetic research should help to better identify the various subtypes of psychiatric disorders as well as the boundaries (when relevant) between the different clinical entities.

Manfred Ackenheil, MD