Research Group 'Psychiatric Genetics', Head: Prof. Dr. Hans H. Stassen

Department of Psychiatry, Psychotherapy and Psychosomatics

Psychiatric Hospital, University of Zurich


Excess Mortality in Psychiatric Populations

Significantly Elevated Suicide Risk

Mortality studies of psychiatric populations have demonstrated excess mortality for most diagnostic subgroups. Amongst the causes of premature death, suicides play a prominent role. Indeed, as many as 15% of unipolars, 10% of bipolars and 8% of schizophrenics commit suicide, in both inpatients and outpatients, and in virtually all countries around the world. These percentages vary by approximately ± 5% across studies, but are remarkably stable over the past decades, thus suggesting that the broad administration of antidepressants and has not substantially influenced suicide rates in psychiatric populations. The extent to which prophylactic lithium treatment reduces the mortality of manic-depressive patients is still the object of investigation, although preliminary results are encouraging. Much emphasis has been laid by researchers on the identification of factors predicting suicide risk in psychiatric patients, as well as on the development of potent therapeutic interventions. Despite intensive efforts, however, effective prediction and intervention strategies have remained elusive. In particular, the lack of robust associations between death rates and any of the patients' characteristics investigated to date suggests that completed suicide might represent an etiologic entity which is largely independent of psychiatric diagnoses. Consequently, the overlap observed, for example, between suicide and affective disorders should be interpreted in terms of "comorbidity", rather than in terms of causal relationships.

Constant Over a Life Time

The results of our investigation into the distribution of suicide risk as a function of age clearly speak in favor of this hypothesis: ⇒ We found the risk of committing suicide to be constant over a lifetime and virtually the same for depressive, schizoaffective, schizophrenic and, with certain restrictions, for borderline patients as well.

Biological Predisposition?

The respective factor showing up across studies could be related to common biological features such as deficiencies in certain transmitter systems. Clearly elevated aggression scores in the premorbid personality of persons who later committed suicide point in the same direction. Our finding that suicide groups show a linear risk function over age points to a serious methodological problem: Since standard approaches to measuring efficacy of anti-suicidal interventions are based on a comparison with the general population, the nonlinearity of the respective risk function with several distinct maxima can be expected to bias results, particularly, if the risk periods under comparison are short. We think that the methodological framework underlying research in this field deserves improvement.


Angst J., Scharfetter C, Stassen HH: Classification of Schizoaffective Patients by Multidimensional Scaling and Cluster Analysis. Psychiatria Clin 1983; 16: 254-264
Angst J, Bänninger R, Nüsperli M, Scharfetter C, Stassen HH: Syndromale Gruppierungen endogener Psychosen in genetischer Sicht. In: Perspektiven der Schizophrenie-Forschung, ed: Pflug B., Foerster K., Straube E.; Fischer, Stuttgart New York, 1985: 25-38
Stassen HH, Scharfetter C, Angst J: Morbid risks of subgroups of affective disorders: some methodological and empirical results. J Psychiat Research 1987; 21: 347-355
Stassen HH, Scharfetter C, Winokur G, Angst J: Familial syndrome patterns in schizophrenia, schizoaffective disorder, mania and depression. Eur Arch Psychiatr Neurol Sci 1988; 237: 115-123
Angst J, Stassen HH, Gross G, Huber G, Stone MH: Suicide in affective and schizoaffective disorders. In: Marneros A. and Tsuang M.T. (eds) Affective and Schizoaffective disorders. Springer, Berlin-Heidelberg 1990: 168-185
Stassen HH, Schmid GB, Gross G, Angst J, Huber G: Prädiktoren des langfristigen Verlaufs schizophrener Erkrankungen. In: G. Huber (ed), Idiopathische Psychosen: Psychopathologie, Neurologie, Therapie. Schattauer, Stuttgart-New York, 1990: 95-104
Scharfetter C, Stassen HH: Psychopathological concepts. Psychopathology 1995; 28: 8-12
Stassen HH, Ragaz M, Reich T: Age-of-onset or age-cohort changes in the lifetime occurrence of depression? Psychiat Genetics 1997; 7: 27-34
Angst J, Stassen HH: Methodische Probleme der Prüfung von Antidepressiva. In: Stieglitz RD, Fähndrich E, Möller HJ (eds): Syndromale Diagnostik psychischer Störungen. Hogrefe, Göttingen 1998: 5-12
Angst J, Angst F, Stassen HH: Suicide risk in patients with major depressive disorder. J Clin Psychiatry 1999; 60,2: 57-62
Angst F, Stassen HH, Clayton PJ, Angst J: Mortality of patients with mood disorders: follow-up over 34 to 38 years. J Aff Disorders 2002; 68: 167-181
Stassen HH: Veränderungen der Sprechmotorik. In: T.Jahn (ed) Bewegungsstörungen bei psychischen Erkrankungen. Springer Heidelberg 2004: 107-125
Angst J, Sellaro R, Stassen HH, Gamma A: Diagnostic conversion from depression to bipolar disorders: results of a long-term prospective study of hospital admissions. J Aff Disorders 2005; 84(2-3): 149-157
Stassen HH, Angst J, Scharfetter C, Szegedi A: Therapie mit Antidepressiva: Erfolg von genetischen Faktoren abhängig? Leading Opinions, Neurologie & Psychiatrie 2005; 6: 25-27
Stassen HH, Scharfetter C: Ethnische Zugehörigkeit und Vulnerabilität am Beispiel der Affektkrankheiten und Schizophrenien. Die Psychiatrie 2005; 2: 85-95
Stassen HH, Angst J, Scharfetter C: Genetik affektiver Störungen —der quantitative Ansatz syndrom-orientierter Modelle. In: M. Leuzinger-Bohleber, S. Hau, H. Deserno (hsg): Depression –Pluralismus in Praxis und Forschung, Vandenhoeck & Ruprecht, Göttingen, 2005, pp. 219-257
Stassen HH, Scharfetter C, Angst J: Functional Psychoses —Molecular-genetic Evidence for a Continuum. In: A. Marneros and H.S. Akiskal (eds) The overlap of affective and schizophrenic spectra. Cambridge University Press 2006; pp. 55-78
Stassen HH, Scharfetter C: Vulnerability, resilience and response to psychotropic drugs: shared genetic factors? Am J Med Genetics 2006; 141: 707-708
Stassen HH, Angst J, Hell D, Scharfetter C, Szegedi A: Is there a common resilience mechanism underlying antidepressant drug response? Evidence from 2848 patients. J Clin Psychiatry 2007; 68(8): 1195-1205
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