The functional psychoses "schizophrenia", "schizoaffective disorder", and "bipolar illness"
represent complex clinical syndromes that are characterized by phenotypic heterogeneity. Yet
evidence from numerous studies suggests that (1) the prevalence of schizophrenia and bipolar
illness is with 1% very similar across ethnicities, and (2) a strong genetic component is
involved in the disorders’ pathogenesis. Using data from different US-American ethnicities
(77 families with a total of 17 unaffected and 170 affected sib pairs; 276 marker loci) we
searched for ethnicity-independent oligogenic susceptibility loci for which the between-sib
genetic similarity in affected sib pairs deviated from the expected values. Specifically, we
addressed the question of the extent to which genetic risk factors and their interactions
constitute multigenic inheritance of functional psychoses across populations and might
constitute universal targets for treatment.
Our genotype-to-phenotype search strategy was based on a genetic similarity function that
allowed us to quantify the inter-individual genetic distances d(Xi,Xj) between the allelic
genotype patterns Xi, Xj of any two subjects i, j with respect to n loci L1, L2, .. Ln. Thus,
we were able to assess the between-ethnicity, the within-ethnicity, and the within-family
genetic similarities. The problem of ethnicity-independent vulnerability was addressed by
treating the Afro-American families as "training" samples, while the NonAfro-American
families served as independent "test" samples. We evaluated the between-sib similarities
which were expected to deviate from "0.5" in affected sib pairs if the region of interest
contained markers close to vulnerability genes. The reference value "0.5" was derived from
the parent-offspring similarities that are always "0.5", irrespective of the affection
status of parents and offspring.
We found 12 vulnerability loci on chromosomes 1, 4, 5, 6, 13, 14, 18 and 20, which were
reproducible across the two samples under comparison and may constitute an ethnicity-independent
oligogenic model of vulnerability to functional psychoses. Families of all index-case related
diagnostic categories contributed to these signals. The elevated vulnerability appeared to be
unspecific and to act in such a way that exogenous factors become more likely to trigger the
onset of psychiatric illnesses. This view was further supported by the fact that some of the
genomic regions identified through this study also showed up with other psychiatric and somatic
conditions, such as alcohol dependence and psoriasis. Derived through a method of approach
different from standard linkage analyses, our results displayed some remarkable overlap with
previous findings in the literature, in particular, for the D13S779 locus along with the
well-known candidate region at D6S1009. Compared to the results of previous linkage analyses
of the NIMH data our analysis yielded the same signals at the D6S462 and D13S797 loci, while
the α-7 nicotinic receptor CNRNA7 on chromosome 15 did not show up among the
NonAfro-Americans, suggesting that ethnical differences might influence, to some extent,
susceptibility to "schizophrenia", "schizoaffective disorder", and "bipolar illness".
Stassen HH, Bachmann S, Bridler R, Cattapan K, Seifritz E. Polypharmacy in Psychiatry and
Weight Gain: Longitudinal Study of 832 Patients Hospitalized for Depression or Schizophrenia,
along with Data of 3,180 Students from Europe, the U.S., South America, and China.
Eur Arch Psychiatry Clin Neurosci. 2024; https://doi.org/10.1007/s00406-024-01767-2
(Epub ahead of print)
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get the article]
Stassen HH, Bachmann S, Bridler R, Cattapan K, Hartmann AM, Rujescu D, Seifritz E, Weisbrod M,
Scharfetter C: Genetic Determinants of Antidepressant and Antipsychotic Drug Response:
A molecular-genetic study of 902 patients over 6 weeks. Psychiatry Res. 2024 [submitted for publication]
Stassen HH, Bachmann S, Bridler R, Cattapan K, Hartmann AM, Rujescu D, Seifritz E, Weisbrod M,
Scharfetter C. Analysis of genetic diversity in patients with major psychiatric disorders
versus healthy controls: A molecular-genetic study of 1698 subjects genotyped for 100 candidate
genes (549 SNPs). Psychiatry Res. 2024; 333: 115720. doi: 10.1016/j.psychres.2024.115720
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Greil W, de Bardeci M, Müller-Oerlinghausen B, Nievergelt N, Stassen HH, Hasler G, Erfurth A,
Cattapan K, Rüther E, Seifert J, Toto S, Bleich S, Schoretsanitis G. Controversies regarding
lithium-associated weight gain: case-control study of real-world drug safety data.
Int J Bipolar Disord. 2023; 11(1): 34. doi: 10.1186/s40345-023-00313-8
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de Bardeci M, Greil W, Stassen H, Willms J, Köberle U, Bridler R, Hasler G, Kasper S, Rüther E,
Bleich S, Toto S, Grohmann R, Seifert J. Dear Doctor Letters regarding citalopram and escitalopram:
guidelines vs real-world data. Eur Arch Psychiatry Clin Neurosci. 2023; 273(1): 65-74
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Stassen HH, Bachmann S, Bridler R, Cattapan K, Herzig D, Schneeberger A, Seifritz E:
Detailing the Effects of Polypharmacy in Psychiatry: Longitudinal Study of 320 Patients
Hospitalized for Depression or Schizophrenia. Eur Arch Psychiatry Clin Neurosci. 2022;
272(4): 603-619
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get the article]
Greil W, de Bardeci M, Seifert J, Bernegger X, Cattapan K, Stassen HH, Wagner AL, Sieberer M,
Grohmann R, Toto S: Treatment of depression: Are psychotropic drugs appropriately dosed in women
and in the elderly? Dosages of psychotropic drugs by sex and age in routine clinical practice.
Hum Psychopharmacol. 2022; 37(1): e2809
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Stassen HH, Bachmann S, Bridler R, Cattapan K, Herzig D, Schneeberger A, Seifritz E:
Inflammatory Processes linked to Major Depression & Schizophrenic Disorders and the Effects
of Polypharmacy in Psychiatry: Evidence from a longitudinal Study of 279 Patients under
Therapy. Eur Arch Psychiatry Clin Neurosci. 2021; 271(3): 507-520
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Pollak TA, Lennox B, Müller S, Benros ME, Prüss H, Tebartz van Elst L, Klein H, Steiner J,
Frodl T, Bogerts B, Tian L, Groc L, Hasan A, Baune BT, Endres D, Haroon E, Yolken R,
Benedetti F, Halaris A, Meyer J, Stassen HH, Leboyer M, Fuchs D, Otto M, Brown DA, Vincent A,
Najjar S, Bechter K: An international consensus on an approach to the diagnosis and
management of psychosis of suspected autoimmune origin: the concept of autoimmune psychosis.
Lancet Psychiatry 2020; 7(1): 93-108
Zhang M, Bridler R, Mohr C, Moragrega I, Sun N, Xu Z, Yang Z, Possenti M, Stassen HH:
Early Detection of the Risk of Developing Psychiatric Disorders: A Study of 461 Chinese University
Students under Chronic Stress. Psychopathology 2019; 52(6): 367-377
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get the article]
Bhake R, Kluckner V, Stassen HH, Russell GM, Leendertz J, Stevens K, Linthorst ACE,
Lightman S: Continuous Free Cortisol Profiles – Circadian Rhythms in Healthy Men.
J Clinical Endocrinology & Metabolism 2019; 104(12): 5935-5947
Stassen HH: Heterogeneity of schizophrenic disorders and link to chronically elevated IgM
values. Neurology, psychiatry and brain research 2018; 29: 23-24
Braun S, Bridler R, Müller N, Schwarz MJ, Seifritz E, Weisbrod M, Zgraggen A, Stassen HH:
Inflammatory Processes and Schizophrenia: Two Independent Lines of Evidence from a Study
of Twins Discordant and Concordant for Schizophrenic Disorders. Eur Arch Psychiatry Clin
Neurosci 2017; 267: 377-389
[
get the article]
Stassen HH, Delfino JP, Kluckner VJ, Lott P, Mohr C: Vulnerabilität und psychische Erkrankung.
Swiss Archives of Neurology and Psychiatry 2014; 165(5): 152-157
Drago A, Giegling I, Schäfer M, Hartmann AM, Friedl M, Konte B, Möller HJ, De Ronchi D, Stassen HH,
Serretti A, Rujescu D: AKAP13, CACNA1, GRIK4 and GRIA1 genetic variations may be associated with
haloperidol efficacy during acute treatment. Eur Neuropsychopharmacol. 2013; 23(8): 887-894
Giegling I, Balzarro B, Porcelli S, Schäfer M, Hartmann AM, Friedl M, Konte B, Krämer P, Möller HJ,
De Ronchi D, Stassen HH, Serretti A, Rujescu D: Influence of ANKK1 and DRD2 polymorphisms in
response to haloperidol. Eur Arch Psychiatry Clin Neurosci. 2013; 263(1): 65-74
Drago A, Giegling I, Schäfer M, Hartmann AM, Möller HJ, De Ronchi D, Stassen HH, Serretti A,
Rujescu D: No association of a set of candidate genes on haloperidol side effects.
PLoS One. 2012; 7(10): e44853
Giegling I, Drago A, Schäfer M, Hartmann AM, Sander T, Toliat MR, Möller HJ, De Ronchi D,
Stassen HH, Rujescu D, Serretti A: Lack of association between 71 variations located in
candidate genes and response to acute haloperidol treatment. Psychopharmacology 2011; 214(3):
719-728
Giegling I, Drago A, Dolzan V, Plesnicar BK, Schäfer M, Hartmann AM, Sander T, Toliat MR,
Möller HJ, Stassen HH, Rujescu D, Serretti A: Glutamatergic gene variants impact the clinical
profile of efficacy and side effects of haloperidol. Pharmacogenet Genomics. 2011; 21(4): 206-216
Gravemann S, Schnipper N, Meyer H, Vaya A, Nowaczyk MJM, Rajab A, Hofmann WK, Salewsky B,
Tönnies H, Neitzel H, Stassen HH, Sperling K, Hoffmann K: Dosage effect of zero to three
functional LBR-genes in vivo and in vitro. Nucleus 2010; 1(2): 1-12
Hoffmann K, Planitz C, Rüschendorf F, Müller-Myhsok B, Stassen HH, Lucke B, Mattheisen M,
Stumvoll M, Bochmann R, Zschornack G, Wienker TF, Nürnberg P, Reis A, Luft FC, Lindner TH: A
novel locus for arterial hypertension on chromosome 1p36 maps to a metabolic syndrome trait
cluster in the Sorbs, a Slavic population isolate in Germany. J Hypertens 2009; 27: 983-990
Stassen HH, Hoffmann K, Scharfetter C: The Difficulties of Reproducing Conventionally Derived
Results through 500k-Chip Technology. BMC Genet Proc. 2009; 3 Suppl 7: S66
Tadic A, Rujescu D, Dahmen N, Stassen HH, Muller MJ, Kohnen R, Szegedi A: Association
Analysis between Variants of the Interleukin-1? and the Interleukin-1 Receptor Antagonist
Gene and Antidepressant Treatment Response in Major Depression. Neuropsychiatr Dis Treat
2008; 4(1): 269-276
Stassen HH, Angst J, Hell D, Scharfetter C, Szegedi A: Is there a common resilience mechanism
underlying antidepressant drug response? Evidence from 2'848 patients. J Clin Psychiatry 2007;
68(8): 1195-1205
Tadic A, Rujescu D, Müller MJ, Kohnen R, Stassen HH, Dahmen N, Szegedi A: A monoamine
oxidase B gene variant and short-term antidepressant treatment response. Prog
Neuropsychopharmacol Biol Psychiatry. 2007; 31(7): 1370-1377
Tadic A, Müller MJ, Rujescu D, Kohnen R, Stassen HH, Dahmen N, Szegedi A: The MAOA
T941G polymorphism and short-term treatment response to mirtazapine and paroxetine in
major depression. Am J Med Genet B Neuropsychiatr Genet. 2007; 144(3): 325-331
Stassen HH, Szegedi A, Scharfetter C: Modeling Activation of Inflammatory Response System.
A Molecular-Genetic Neural Network Analysis. BMC Proceedings 2007, 1 (Suppl 1): S61, 1-6
Berger M, Stassen HH, Köhler K, Krane V, Mönks D, Wanner C, Hoffmann K, Hoffmann MM, Zimmer M,
Bickeböller H, Lindner TH: Hidden population substructures in an apparently homogeneous
population bias association studies. Eur J Hum Genetics 2006; 14: 236-244
Stassen HH, Angst J, Scharfetter C, Szegedi A: Therapie mit Antidepressiva: Erfolg von
genetischen Faktoren abhängig? Leading Opinions, Neurologie & Psychiatrie 2005; 6: 25-27
Szegedi A, Rujescu D, Tadic A, Müller MJ, Ralf Kohnen R, Stassen HH, Dahmen N: The
catechol-O-methyltransferase Val108/158Met-polymorphism affects short-term treatment response
to mirtazapine, but not to paroxetine in Major Depression. Pharmacogenomics 2005; 5(1): 49-53
Stassen HH, Bridler R, Hell D, Weisbrod M, Scharfetter C: Ethnicity-independent genetic basis
of functional psychoses. A Genotype-to-phenotype approach. Am J Med Genetics B 2004; 124:
101-112
Stassen HH, Hoffmann K, Scharfetter C: Similarity by state/descent and genetic vector spaces:
Analysis of a longitudinal family study. Genetic Analysis Workshop 13: Analysis of longitudinal
family data for complex diseases and related risk factors. BMC Genet 2003; 4, S59: 1-6
Stassen HH, Scharfetter C: Oligogenic approaches to the predisposition of asthma in ethnically
diverse populations. Genetic Analysis Workshop 12: Analysis of genetic and environmental factors
in common diseases. Genetic Epidemiology 2001; 21(1): 284-289
Hoffmann K, Stassen HH, Reis A: Genkartierung in Isolatpopulationen. Medizinische Genetik 2000;
12,4: 428-437
Stassen HH, Bridler R, Hägele S, Hergersberg M, Mehmann B, Schinzel A, Weisbrod M, Scharfetter C:
Schizophrenia and smoking: evidence for a common neurobiological basis?
Am J Med Genetics B 2000; 96: 173-177
Stassen HH and Scharfetter C: Integration of genetic maps by polynomial transformations.
Am J Med Genetics B 2000; 96: 108-113
Stassen HH, Begleiter H, Porjesz B, Rice J, Scharfetter C, Reich T: Structural decomposition of
genetic diversity in families with alcohol dependence. Genetic Analysis Workshop 11: Analysis
of genetic and environmental factors in common diseases. Genetic Epidemiology 1999; 17:
325-330