Sommer, Prof. Iris
Iris Sommer is Professor of Psychiatry at the University Medical Center Groningen. She is an international expert in neuropsychiatry. Her research addresses the origins of psychiatric disorders and the development of innovative treatments. Sommer trained as a physician and psychiatrist, obtained her PhD cum laude in the field of schizophrenia, and founded the Stemmenpoli (Voices Clinic) at the UMC Utrecht. In 2017, her research on hallucinations ‘Zie ik spoken’ [Do I see ghosts?], was voted public research of the year.
Iris Sommer's pioneering work focuses, among other things, on the surprising fact that the female brain is much less well studied than the male brain. One of Sommer's key findings is that female hormones (such as estrogens) play a major protective role in psychotic disorders. While commonly prescribed antipsychotics actually appear to suppress the production of estrogens.
Current psychiatric treatments are mostly based on clinical studies in which women are underrepresented. This results in treatment for women being less evidence-based than for men, the consequences of which are significant. For instance, diagnoses in women are more delayed, and sometimes missed altogether. Furthermore, treatments are not as suitable, making women more likely to overdose and therefore have side effects. And menopause is not taken into account either.
Sommer wrote several books, including Haperende Hersenen [Faltering brains] and De Zeven Zintuigen [The seven senses]. The book is about how we perceive the world only partly with our senses and supplement the rest from our background. With BNR Nieuwsradio, Sommer recorded five podcasts, covering various topics related to the brain.
Previously in the news
Dr Iris Sommer at the University of the Netherlands:
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Publications
2025
Solmi,
M., Thompson, T., Cortese, S., Estradé, A., Agorastos, A.,
Radua, J., Dragioti, E., Vancampfort, D., Thygesen, L. C.,
Aschauer, H., Schlögelhofer, M., Aschauer, E., Schneeberger,
A., Huber, C. G., Hasler, G., Conus, P., Cuénod, K. Q. D., von
Känel, R., Arrondo, G., ... Sommer, I. (2025).
Collaborative outcomes study on health and functioning during
infection times (COH-FIT): Insights on modifiable and
non-modifiable risk and protective factors for wellbeing and mental
health during the COVID-19 pandemic from multivariable and network
analyses. European
Neuropsychopharmacology, 90, 1-15. https://doi.org/10.1016/j.euroneuro.2024.07.010
2024
TAPER
international research consortium, Koops, S., Allott,
K., De Haan, L., Chen, E., Hui, C., Killackey, E., Long, M.,
Moncrieff, J., Sommer, I., Stürup, A. E.,
Wunderink, L., & Begemann, M. (2024).
Addressing the Evidence to Practice Gap: What to Expect from
International Antipsychotic Dose Reduction Studies in the Tapering
Anti-Psychotics and Evaluating Recovery Consortium.
Schizophrenia Bulletin, 50(1), 5-8.
https://doi.org/10.1093/schbul/sbad112
King,
B., Kempton, M. J., Broberg, B. V., Merritt, K., Barker, G. J.,
Lythgoe, D. J., Perez-Iglesias, R., Baandrup, L., Düring, S.
W., Stone, J. M., Rostrup, E., Sommer, I. E.,
Glenthøj, B., Kahn, R. S., Dazzan, P., McGuire, P. K., &
Egerton, A. (2024). A letter to the editor: The effects of
alcohol use on brain glutamate in first episode psychosis.
Schizophrenia Research, 266,
234-236. https://doi.org/10.1016/j.schres.2024.02.013
van
Zonneveld, S. M., van den Oever, E. J.,
Haarman, B. C. M., Grandjean, E. L., Nuninga, J.
O., van de Rest, O., & Sommer, I. E. C.
(2024). An Anti-Inflammatory Diet and Its Potential Benefit
for Individuals with Mental Disorders and Neurodegenerative
Diseases—A Narrative Review.
Nutrients, 16(16), Article 2646. https://doi.org/10.3390/nu16162646
de
Haan, L., Gangadin, S. S., de Beer,
F., Djordjevic, M., Begemann, M. J.
H., & Sommer, I. E. C. (2024).
Antipsychotica na een eerste psychose.
Nederlands Tijdschrift voor Geneeskunde,
168, Article D7594. https://www.ntvg.nl/artikelen/antipsychotica-na-een-eerste-psychose
HAMLETT
OPHELIA Consortium, de Beer, F., Wijnen,
B., Wouda, L., Koops, S., Gangadin,
S., Veling, W., van Beveren, N., de Haan,
L., Begemann, M. J. H., Sommer, I. E.
C., & Djordjevic, M. (2024).
Antipsychotic dopamine D2 affinity and negative
symptoms in remitted first episode psychosis patients.
Schizophrenia Research, 274,
299-306. https://doi.org/10.1016/j.schres.2024.09.030
Brand,
B. A., de Boer, J. N., Willemse, E. J.
M., Weickert, C. S., Sommer, I. E., &
Weickert, T. W. (Accepted/In press). Antipsychotic-induced
prolactin elevation in premenopausal women with schizophrenia:
associations with estrogen, disease severity and cognition.
Archives of Women's Mental Health. https://doi.org/10.1007/s00737-024-01491-9
d'Angremont,
E., van der Zee, S., Slingerland,
S., Slomp, A. C., de Vries, E. F.
J., van Laar, T., & Sommer, I.
E. (2024). Cholinergic deficiency in Parkinson's
disease patients with visual hallucinations. Brain
: a Journal of Neurology, 147(10),
3370–3378. https://doi.org/10.1093/brain/awae186
Marschall,
T. M., Brederoo, S. G., Koops,
S., Ćurčić-Blake, B.,
& Sommer, I. E. C. (2024). Content-based
clustering of hallucinations across sensory modalities in a large
online survey. Scientific Reports,
14, Article 23108. https://doi.org/10.1038/s41598-024-69798-2
Brand,
B. A., Willemse, E. J. M., Hamers, I. M.
H., & Sommer, I. E. (2024).
Correction to: Evidence-Based Recommendations for the
Pharmacological Treatment of Women with Schizophrenia Spectrum
Disorders (Current Psychiatry Reports, (2023), 25, 11, (723-733),
10.1007/s11920-023-01460-6). Current Psychiatry
Reports, 26(10), 550-551. https://doi.org/10.1007/s11920-024-01520-5
Zaki,
J. K., Lago, S. G., Spadaro, B., Rustogi, N., Gangadin, S.
S., Benacek, J., Drexhage, H. A., de Witte, L. D., Kahn, R.
S., Sommer, I. E. C., Bahn, S., & Tomasik, J.
(2024). Exploring peripheral biomarkers of response to
simvastatin supplementation in schizophrenia.
Schizophrenia Research, 266, 66-74.
https://doi.org/10.1016/j.schres.2024.02.011
Solmi,
M., Thompson, T., Estradé, A., Agorastos, A., Radua, J.,
Cortese, S., Dragioti, E., Vancampfort, D., Thygesen, L. C.,
Aschauer, H., Schlögelhofer, M., Aschauer, E., Schneeberger,
A., Huber, C. G., Hasler, G., Conus, P., Cuénod, K. Q. D., von
Känel, R., Arrondo, G., ... Correll, C. U. (2024).
Global and risk-group stratified well-being and mental health
during the COVID-19 pandemic in adults: Results from the
international COH-FIT Study. Psychiatry
Research, 342, Article 115972. https://doi.org/10.1016/j.psychres.2024.115972
Gangadin,
S. S., Enthoven, A. D., van Beveren, N. J.
M., Laman, J. D., & Sommer, I. E. C.
(2024). Immune Dysfunction in Schizophrenia Spectrum
Disorders. Annual review of clinical
psychology, 20(1), 229-257. https://doi.org/10.1146/annurev-clinpsy-081122-013201
Li,
Y., Yolland, C. O. B., Rossell, S. L., Sommer, I. E.
C., & Toh, W. L. (2024). Multisensory
hallucinations and other unusual sensory experiences in the context
of migraine: a systematic review. Journal of
Neurology, 271, 1717–1746. https://doi.org/10.1007/s00415-023-12144-9
Borkent,
J., Ioannou, M., Neijzen,
D., Haarman, B. C. M., & Sommer, I.
E. C. (2024). Probiotic Formulation for Patients With
Bipolar or Schizophrenia Spectrum Disorder: A Double-Blind,
Randomized Placebo-Controlled Trial. Schizophrenia
Bulletin, Article sbae188. Advance online publication.
https://doi.org/10.1093/schbul/sbae188
HAMLETT
OPHELIA Consortium, de Beer, F., Koops,
S., Schoevers, R. A., Veling, W.,
van Beveren, N., de Haan, L., & Boonstra, N.
(2024). Psychiatrists effect on positive symptom severity and
daily functioning during pharmacotherapy for first-episode
psychosis patients. Scientific
Reports, 14(1), Article 22871. https://doi.org/10.1038/s41598-024-72678-4
van
Opstal, D. P. J., Kia, S. M., Jakob, L., Somers, M., Sommer,
I. E. C., Winter-van Rossum, I., Kahn, R. S., Cahn, W.,
& Schnack, H. G. (2024). Psychosis Prognosis Predictor: A
continuous and uncertainty-aware prediction of treatment outcome in
first-episode psychosis. Acta Psychiatrica
Scandinavica. Advance online publication. https://doi.org/10.1111/acps.13754
Brand,
B. A., Sommer, I. E., Gangadin, S.
S., Tanskanen, A., Tiihonen, J., & Taipale, H. (2024).
Real-World Effectiveness of Menopausal Hormone Therapy in
Preventing Relapse in Women With Schizophrenia or Schizoaffective
Disorder. The American journal of
psychiatry, 181(10), 893-900. https://doi.org/10.1176/appi.ajp.20230850
Ioannou,
M., Borkent, J., Andreu-Sánchez,
S., Wu, J., Fu, J., Sommer,
I. E. C., & Haarman, B. C. M. (2024).
Reproducible gut microbial signatures in bipolar and
schizophrenia spectrum disorders: A metagenome-wide study.
Brain, Behavior, and Immunity, 121,
165-175. https://doi.org/10.1016/j.bbi.2024.07.009
Sommer,
I. E., Brand, B. A., Stuijt, C. C. M.,
& Touw, D. J. (2024). Sex differences need to be
considered when treating women with psychotropic drugs.
World psychiatry, 23(1), 151-152. https://doi.org/10.1002/wps.21155
De
jager, J. E., Boesjes, R., Roelandt, G.
H. J., Koliaki, I., Sommer, I. E.
C., Schoevers, R. A., & Nuninga, J.
O. (2024). Shared effects of electroconvulsive shocks
and ketamine on neuroplasticity: A Systematic Review of Animal
Models of Depression. Neuroscience &
Biobehavioral Reviews, 164, Article 105796. https://doi.org/10.1016/j.neubiorev.2024.105796
d'Angremont,
E., Sommer, I. E. C., van der Zee,
S., van Laar, T., de Vries, E. F.
J., & Zijdewind, I. (2024).
Short-latency afferent inhibition as a biomarker of
cholinergic degeneration compared to PET imaging in Parkinson's
disease. Parkinsonism & Related
Disorders, 121, Article 106032. https://doi.org/10.1016/j.parkreldis.2024.106032
Hamers,
I. M. H., Brand, B. A., Begemann, M. J.
H., Weickert, C. S., Weickert, T. W., & Sommer, I.
E. C. (2024). The association of prolactin and gonadal
hormones with cognition and symptoms in men with schizophrenia
spectrum disorder: Divergent effects of testosterone and
estrogen. Schizophrenia Research,
270, 273-280. https://doi.org/10.1016/j.schres.2024.06.022
Brederoo,
S. G., Alderson-Day, B., de Boer, J. N.,
Linszen, M. M. J., & Sommer, I. E. C.
(2024). The experience of felt presence in a general
population sample. British Journal of
Psychiatry, 224(4), 119-121. https://doi.org/10.1192/bjp.2024.7
Khaled,
S. M., Brederoo, S. G., Alabdulla, M., Sommer,
I. E. C., & Woodruff, P. W. (2024). The role of
religiosity types in the phenomenology of hallucinations: A large
cross-sectional community-based study in a predominantly Muslim
society. Schizophrenia Research,
265, 30-38. https://doi.org/10.1016/j.schres.2022.11.003
2023
Toh,
W. L., Yolland, C. O., Li, Y., Sommer, I. E., &
Rossell, S. (2024). Multisensory Hallucinatory Experiences in
Migraine: A Preliminary Basis for Olfactory, Somatic-Tactile, and
Gustatory Auras. Neurology: Clinical
Practice, 14(1), Article e200217. https://doi.org/10.1212/CPJ.0000000000200217
van
der Heijden-Hobus, I. M. W., Rosema, B. S., Vorstman, J. A.
S., Kas, M. J. H., Franke, S. K., Boonstra,
N., & Sommer, I. E. C. (2024).
Personal preferences for treatment and care during and after
a First Episode Psychosis: A qualitative study.
Early intervention in psychiatry,
18(6), 415-424. https://doi.org/10.1111/eip.13477
Fond,
G., Mallet, J., Urbach, M., Benros, M. E., Berk, M., Billeci, M.,
Boyer, L., Correll, C. U., Fornaro, M., Kulkarni, J., Leboyer, M.,
Llorca, P. M., Misdrahi, D., Rey, R., Schürhoff, F., Solmi,
M., Sommer, I. E. C., Stahl, S. M., Pignon, B., &
Berna, F. (2023). Adjunctive agents to antipsychotics in
schizophrenia: A systematic umbrella review and recommendations for
amino acids, hormonal therapies and anti-inflammatory drugs.
BMJ mental health, 26(1), Article
e300771. https://doi.org/10.1136/bmjment-2023-300771
Aleman,
A., & Sommer, I. E. C. (2023).
Advances in Hallucination Research.
Schizophrenia Bulletin, 49(1),
S1-S2. https://doi.org/10.1093/schbul/sbac210
Luykx,
J. J., Gonzalez-Diaz, J. M., Guu, T. W., van der Horst, M. Z., van
Dellen, E., Boks, M. P., Guloksuz, S., DeLisi, L. E., Sommer,
I. E., Cummins, R., Shiers, D., Lee, J., Every-Palmer, S.,
Mhalla, A., Chadly, Z., Chan, S. K. W., Cotes, R. O., Takahashi,
S., Benros, M. E., ... Tiihonen, J. (2023). An international
research agenda for clozapine-resistant schizophrenia.
The Lancet Psychiatry, 10(8),
644-652. https://doi.org/10.1016/S2215-0366(23)00109-8
Brand,
B. A., Haveman, Y. R. A., de Beer, F., de
Boer, J. N., Dazzan, P., & Sommer, I. E. C.
(2023). Antipsychotic medication for women with schizophrenia
spectrum disorders: CORRIGENDUM. Psychological
Medicine, 53(10), 4832. https://doi.org/10.1017/S0033291723001344
Scheurink,
T. A. W., Borkent, J., Gangadin, S.
S., El Aidy, S., Mandl, R., & Sommer,
I. E. C. (2023). Association between gut permeability,
brain volume, and cognition in healthy participants and patients
with schizophrenia spectrum disorder. Brain and
Behavior, 13(6), Article e3011. https://doi.org/10.1002/brb3.3011
Van
der A, J., De Jager, J. E., van Dellen, E., Mandl, R.
C. W., Somers, M., Boks, M. P. M., Sommer, I. E.
C., & Nuninga, J. O. (2023). Changes
in perfusion, and structure of hippocampal subfields related to
cognitive impairment after ECT: A pilot study using ultra high
field MRI. Journal of Affective
Disorders, 325, 321-328. https://doi.org/10.1016/j.jad.2023.01.016
D'Angremont,
E., Begemann, M. J. H., Van Laar,
T., & Sommer, I. E. C. (2023).
Cholinesterase Inhibitors for Treatment of Psychotic Symptoms
in Alzheimer Disease and Parkinson Disease: A Meta-analysis.
Jama neurology, 80(8), 813-823. https://doi.org/10.1001/jamaneurol.2023.1835
Kruiper,
C., Sommer, I. E. C., Koster, M., Bakker, P. R.,
Durston, S., & Oranje, B. (2023). Clonidine augmentation
in patients with schizophrenia: A double-blind, randomized
placebo-controlled trial. Schizophrenia
Research, 255, 148-154. https://doi.org/10.1016/j.schres.2023.03.039
Ciampelli,
S., Voppel, A. E., de Boer, J.
N., Koops, S., & Sommer, I. E.
C. (2023). Combining automatic speech recognition with
semantic natural language processing in schizophrenia.
Psychiatry Research, 325, Article
115252. https://doi.org/10.1016/j.psychres.2023.115252
Gangadin,
S. S., Germann, M., de Witte, L. D., Gelderman,
K. A., Mandl, R. C. W., & Sommer, I. E. C. (2023).
Complement component 4A protein levels are negatively related
to frontal volumes in patients with schizophrenia spectrum
disorders. Schizophrenia Research,
261, 6-14. https://doi.org/10.1016/j.schres.2023.08.031
Khaled,
S. M., Brederoo, S. G., Yehya, A., Alabdulla, M.,
Woodruff, P. W., & Sommer, I. E. C. (2023).
Cross-cultural Differences in Hallucinations: A Comparison
Between Middle Eastern and European Community-Based Samples.
Schizophrenia Bulletin, 49(1),
S13-S24. https://doi.org/10.1093/schbul/sbac086
Brand,
B. A., Willemse, E. J. M., Hamers, I. M.
H., & Sommer, I. E. (2023).
Evidence-Based Recommendations for the Pharmacological
Treatment of Women with Schizophrenia Spectrum Disorders.
Current Psychiatry Reports, 25(11),
723-733. https://doi.org/10.1007/s11920-023-01460-6
Kübler,
R., Ormel, P. R., Sommer, I. E. C., Kahn, R. S., &
de Witte, L. D. (2023). Gene expression profiling of
monocytes in recent-onset schizophrenia. Brain,
Behavior, and Immunity, 111, 334-342. https://doi.org/10.1016/j.bbi.2023.04.019
Marschall,
T. M., van Dijk, P., Kluk, K., Koops,
S., Linszen, M. M. J., Griffiths, T. D., Toh,
W. L., Malicka, A. N., Kovačić, D., Mulert, C.,
Sommer, I. E. C., & Ćurčić-Blake,
B. (2023). Hallucinations in Hearing Impairment: How
Informed Are Clinicians? Schizophrenia
Bulletin, 49(S1), S33–S40. https://doi.org/10.1093/schbul/sbac034
Koops,
S., Brederoo, S. G., Voppel, A.
E., & Sommer, I. E. C. (2023).
Herkennen van depressie met computationele
taalanalyse. Tijdschrift voor
Psychiatrie, 65(3), 198-201. https://www.tijdschriftvoorpsychiatrie.nl/nl/artikelen/article/50-13129_Herkennen-van-depressie-met-computationele-taalanalyse
van
den Heuvel, M. P., Ardesch, D. J., Scholtens, L. H., de Lange, S.
C., van Haren, N. E. M., Sommer, I. E. C., Dannlowski,
U., Repple, J., Preuss, T. M., Hopkins, W. D., & Rilling, J. K.
(2023). Human and chimpanzee shared and divergent
neurobiological systems for general and specific cognitive brain
functions. Proceedings of the National Academy of
Sciences of the United States of America,
120(22), Article e2218565120. https://doi.org/10.1073/pnas.2218565120
Tan,
E. J., Sommer, I. E. C., & Palaniyappan, L.
(2023). Language and Psychosis: Tightening the
Association. Schizophrenia Bulletin,
49(2), S83-S85. https://doi.org/10.1093/schbul/sbac211
So,
S. H. W., Chau, A. K. C., Chung, L. K. H., Leung, C. M., Chong, G.
H. C., Chang, W. C., Mak, A. D. P., Chan, S. S. M., Lee, S.,
& Sommer, I. E. (2023). Moment-To-moment affective
dynamics in schizophrenia and bipolar disorder.
European Psychiatry, 66(1), Article
e67. https://doi.org/10.1192/j.eurpsy.2023.2438
Corona
Hernández, H., Corcoran, C., Achim, A. M., de
Boer, J. N., Boerma, T., Brederoo, S. G.,
Cecchi, G. A., Ciampelli, S., Elvevåg, B.,
Fusaroli, R., Giordano, S., Hauglid, M., van Hessen, A., Hinzen,
W., Homan, P., de Kloet, S. F., Koops, S., Kuperberg,
G. R., Maheshwari, K., ... Palaniyappan, L. (2023).
Natural Language Processing Markers for Psychosis and Other
Psychiatric Disorders: Emerging Themes and Research Agenda From a
Cross-Linguistic Workshop. Schizophrenia
Bulletin, 49(2), S86-S92. https://doi.org/10.1093/schbul/sbac215
Jairaj,
C., Seneviratne, G., Bergink, V., Sommer, I. E., &
Dazzan, P. (2023). Postpartum psychosis: A proposed treatment
algorithm. Journal of
Psychopharmacology, 37(10), 960-970. https://doi.org/10.1177/02698811231181573
van
der Weijden-Germann, M., Brederoo, S. G.,
Linszen, M. M. J., & Sommer, I. E. C.
(2023). Recreational Drug Use and Distress From
Hallucinations in the General Dutch Population.
Schizophrenia Bulletin, 49(1),
S41-S47. https://doi.org/10.1093/schbul/sbac190
Borkent,
J., Ioannou, M., Folkertsma, T.,
Wardenaar, K. J., Haarman, B. C. M., van
Goor, H., Sommer, I. E. C., &
Bourgonje, A. R. (2023). Serum free thiols in recently
diagnosed patients with schizophrenia spectrum disorder: a
potentially useful biomarker of oxidative stress.
Psychiatry Research, 321, Article
115075. https://doi.org/10.1016/j.psychres.2023.115075
Brederoo,
S. G., de Boer, J. N., Linszen, M. M.
J., Blom, R. E., Begemann, M. J. H.,
& Sommer, I. E. C. (2023). Social Deafferentation
and the Relation Between Loneliness and Hallucinations.
Schizophrenia Bulletin, 49(1),
S25-S32. https://doi.org/10.1093/schbul/sbac064
Ciampelli,
S., de Boer, J. N., Voppel, A.
E., Corona Hernandez, H., Brederoo, S.
G., van Dellen, E., Mota, N. B., & Sommer, I. E.
C. (2023). Syntactic Network Analysis in
Schizophrenia-Spectrum Disorders. Schizophrenia
Bulletin, 49(2), S172-S182. https://doi.org/10.1093/schbul/sbac194
Yehya,
A., Khaled, S. M., Sommer, I. E. C., Elhag, S. F.,
Hassan, M. H. M. O., Woodruff, P., & Alabdalla, M. (2023).
The Arabic Questionnaire for Psychotic Experiences in
patients with psychotic disorders: a clinical validation.
BMC Psychiatry, 23(1), Article 141.
https://doi.org/10.1186/s12888-023-04649-4
HAMLETT
and OPHELIA Consortium, Enthoven, A.-S. D.,
Gangadin, S. S., de Haan, L., Veling, W.,
de Vries, E. F. J., Doorduin, J.,
Begemann, M. J. H., & Sommer, I. E. C.
(2023). The association of childhood trauma with depressive
and negative symptoms in recent onset psychosis: a sex-specific
analysis. Psychological Medicine,
53, 7795–7804. https://doi.org/10.1017/S0033291723001824
Brand,
B. A., de Boer, J. N., Marcelis, M. C.,
Grootens, K. P., Luykx, J. J., & Sommer, I. E.
(2023). The Direct and Long-Term Effects of Raloxifene as
Adjunctive Treatment for Schizophrenia-Spectrum Disorders: A
Double-Blind, Randomized Clinical Trial.
Schizophrenia Bulletin, 49(6),
1579-1590. https://doi.org/10.1093/schbul/sbad058
Jeuring,
H. W., D'Angremont, E., Tol, J. M. H.,
Risselada, A. J., Sommer, I. E. C., &
Oude Voshaar, R. C. (2023). The effectiveness of
off-label dopamine stimulating agents in depressive disorder: A
systematic review and meta-analysis. Psychiatry
Research, 319, Article 115010. https://doi.org/10.1016/j.psychres.2022.115010
Marschall,
T. M., Koops, S., Brederoo, S. G.,
Cabral, J., Ćurčić-Blake, B.,
& Sommer, I. E. C. (2023). Time varying dynamics
of hallucinations in clinical and non-clinical
voice-hearers. NeuroImage: Clinical,
37, Article 103351. https://doi.org/10.1016/j.nicl.2023.103351
Solmi,
M., Thompson, T., Estradé, A., Agorastos, A., Radua, J.,
Cortese, S., Dragioti, E., Leisch, F., Vancampfort, D., Thygesen,
L. C., Aschauer, H., Schlögelhofer, M., Aschauer, E.,
Schneeberger, A., Huber, C. G., Hasler, G., Conus, P., Do
Cuénod, K. Q., von Känel, R., ... Correll, C. U. (2023).
Validation of the Collaborative Outcomes study on Health and
Functioning during Infection Times (COH-FIT) questionnaire for
adults. Journal of Affective
Disorders, 326, 249-261. https://doi.org/10.1016/j.jad.2022.12.022
2022
Gangadin,
S. S., Mandl, R. C. W., de Witte, L. D., van Haren, N. E.
M., Schutte, M. J. L., Begemann, M. J.
H., Kahn, R. S., & Sommer, I. E. C. (2024).
Lower fractional anisotropy without evidence for
neuro-inflammation in patients with early-phase schizophrenia
spectrum disorders. Schizophrenia
Research, 264, 557-566. https://doi.org/10.1016/j.schres.2022.12.009
Corona
Hernández, H., de Boer, J.,
Brederoo, S., Voppel, A., & Sommer,
I. E. C. (2023). Assessing coherence through
linguistic connectives: Analysis of speech in patients with
schizophrenia-spectrum disorders. Schizophrenia
Research, 259, 48-58. https://doi.org/10.1016/j.schres.2022.06.013
Hugdahl,
K., Craven, A. R., Johnsen, E., Ersland, L., Stoyanov, D.,
Kandilarova, S., Sandoy, L. B., Kroken, R. A., Loberg, E.-M.,
& Sommer, I. E. (2023). Neural Activation in the
Ventromedial Prefrontal Cortex Precedes Conscious Experience of
Being in or Out of a Transient Hallucinatory State.
Schizophrenia Bulletin, 49(1),
S58–S67. https://doi.org/10.1093/schbul/sbac028
Voppel,
A. E., de Boer, J. N., Brederoo, S.
G., Schnack, H. G., & Sommer, I. E. C.
(2023). Semantic and Acoustic Markers in
Schizophrenia-Spectrum Disorders: A Combinatory Machine Learning
Approach. Schizophrenia Bulletin,
49(2), S163-S171. https://doi.org/10.1093/schbul/sbac142
Sommer,
I. E., Brand, B. A., Gangadin, S.,
Tanskanen, A., Tiihonen, J., & Taipale, H. (2023). Women
with Schizophrenia-Spectrum Disorders After Menopause: A Vulnerable
Group for Relapse. Schizophrenia
Bulletin, 49(1), 136–143. https://doi.org/10.1093/schbul/sbac139
Corona
Hernández, H., Brederoo, S., de
Boer, J., & Sommer, I. E. C. (2022).
A data-driven linguistic characterization of hallucinated
voices in clinical and non-clinical voice-hearers.
Schizophrenia Research, 241,
210-217. https://doi.org/10.1016/j.schres.2022.01.055
Grandjean,
E. L., van Zonneveld, S. M., Sommer, I. E.
C., & Haarman, B. C. M. (2022).
Anti-inflammatory dietary patterns to treat bipolar
disorder? Journal of Affective
Disorders, 311, 254-255. https://doi.org/10.1016/j.jad.2022.05.073
Sommer,
I. E. C., Horowitz, M., Allott, K., Speyer, H., &
Begemann, M. J. H. (2022). Antipsychotic maintenance
treatment versus dose reduction: how the story continues.
The Lancet Psychiatry, 9(8),
602-603. https://doi.org/10.1016/S2215-0366(22)00230-9
Brand,
B. A., Haveman, Y. R. A., De Beer, F., De
Boer, J. N., Dazzan, P., & Sommer, I. E. C.
(2022). Antipsychotic medication for women with schizophrenia
spectrum disorders. Psychological
Medicine, 52(4), 649 - 663. https://doi.org/10.1017/S0033291721004591
Eltokhi,
A., & Sommer, I. E. (2022). A Reciprocal
Link Between Gut Microbiota, Inflammation and Depression: A Place
for Probiotics? Frontiers in
Neuroscience, 16, Article 852506. https://doi.org/10.3389/fnins.2022.852506
de
Rijke, T. J., Doting, M. H. E., van Hemert, S.,
De Deyn, P. P., van Munster, B. C.,
Harmsen, H. J. M., & Sommer, I. E. C.
(2022). A Systematic Review on the Effects of Different Types
of Probiotics in Animal Alzheimer's Disease Studies.
Frontiers in Psychiatry, 13, Article
879491. https://doi.org/10.3389/fpsyt.2022.879491
Puvogel,
S., Palma, V., & Sommer, I. E. C. (2022).
Brain vasculature disturbance in schizophrenia.
Current opinion in psychiatry,
35(3), 146-156. https://doi.org/10.1097/YCO.0000000000000789
Oomen,
P. P., de Boer, J. N., Brederoo, S.
G., Voppel, A. E., Brand, B. A.,
Wijnen, F. N. K., & Sommer, I. E. C. (2022).
Characterizing speech heterogeneity in schizophrenia-spectrum
disorders. Journal of psychopathology and clinical
science, 131(2), 172-181. https://doi.org/10.1037/abn0000736
Zaki,
J. K., Lago, S. G., Rustogi, N., Gangadin, S. S.,
Benacek, J., van Rees, G. F., Haenisch, F., Broek, J. A.,
Suarez-Pinilla, P., Ruland, T., Auyeung, B., Mikova, O., Kabacs,
N., Arolt, V., Baron-Cohen, S., Crespo-Facorro, B., Drexhage, H.
A., de Witte, L. D., Kahn, R. S., ... Tomasik, J. (2022).
Diagnostic model development for schizophrenia based on
peripheral blood mononuclear cell subtype-specific expression of
metabolic markers. Translational
Psychiatry, 12, Article 457. https://doi.org/10.1038/s41398-022-02229-w
Adam,
O., Blay, M., Brunoni, A. R., Chang, H.-A., Gomes, J. S., Javitt,
D. C., Jung, D.-U., Kantrowitz, J. T., Koops, S.,
Lindenmayer, J.-P., Palm, U., Smith, R. C., Sommer, I.
E., Lane Valiengo, L. D. C., Weickert, T. W., Brunelin, J.,
& Mondino, M. (2022). Efficacy of Transcranial Direct
Current Stimulation to Improve Insight in Patients With
Schizophrenia: A Systematic Review and Meta-analysis of Randomized
Controlled Trials. Schizophrenia
Bulletin, 48(6), 1284–1294. https://doi.org/10.1093/schbul/sbac078
Sommer,
I. E., & N de Boer, J. (2022). How to
reap the benefits of language for psychiatry.
Psychiatry Research, 318, Article
114932. https://doi.org/10.1016/j.psychres.2022.114932
Aichholzer,
M., Gangadin, S. S., Sommer, I. E. C.,
Wijkhuis, A., de Witte, L. D., Kahn, R. S., Bahn, S., Drexhage, H.
A., & Schiweck, C. (2022). Inflammatory monocyte gene
signature predicts beneficial within group effect of simvastatin in
patients with schizophrenia spectrum disorders in a secondary
analysis of a randomized controlled trial. Brain,
Behavior, and Immunity - Health, 26, Article
100551. https://doi.org/10.1016/j.bbih.2022.100551
Jansma,
J., van Essen, R., Haarman, B. C. M.,
Chatziioannou, A. C., Borkent, J., Ioannou,
M., van Hemert, S., Sommer, I. E. C.,
& El Aidy, S. (2022). Metabolic phenotyping
reveals a potential link between elevated faecal amino acids, diet
and symptom severity in individuals with severe mental
illness. Journal of Psychiatric
Research, 151, 507-515. https://doi.org/10.1016/j.jpsychires.2022.05.011
Schutte,
M. J. L., Voppel, A., Collin, G., Abramovic,
L., Boks, M. P. M., Cahn, W., van Haren, N. E. M., Hugdahl,
K., Koops, S., Mandl, R. C. W., & Sommer, I.
E. C. (2022). Modular-Level Functional Connectome
Alterations in Individuals With Hallucinations Across the Psychosis
Continuum. Schizophrenia Bulletin,
48(3), 684–694. https://doi.org/10.1093/schbul/sbac007
Linszen,
M. M. J., de Boer, J. N., Schutte, M. J.
L., Begemann, M. J. H., de Vries, J.,
Koops, S., Blom, R. E., Bohlken, M. M., Heringa, S. M.,
Blom, J. D., & Sommer, I. E. C. (2022).
Occurrence and phenomenology of hallucinations in the general
population: A large online survey.
Schizophrenia, 8, Article 41. https://doi.org/10.1038/s41537-022-00229-9
Solmi,
M., Estrade, A., Thompson, T., Agorastos, A., Radua, J., Cortese,
S., Dragioti, E., Leisch, F., Vancampfort, D., Thygesen, L. C.,
Aschauer, H., Schloegelhofer, M., Akimova, E., Schneeberger, A.,
Huber, C. G., Hasler, G., Conus, P., Do Cuenod, K. Q., von Kanel,
R., ... Sommer, I. (2022). Physical and mental
health impact of COVID-19 on children, adolescents, and their
families: The Collaborative Outcomes study on Health and
Functioning during Infection Times-Children and Adolescents
(COH-FIT-C&A). Journal of Affective
Disorders, 299, 367-376. https://doi.org/10.1016/j.jad.2021.09.090
Sommer,
I. E. C., & DeLisi, L. E. (2022). Precision
psychiatry and the clinical care for people with schizophrenia:
sex, race and ethnicity in relation to social determinants of
mental health. Current opinion in
psychiatry, 35(3), 137-139. https://doi.org/10.1097/YCO.0000000000000781
Yehya,
A., Khaled, S. M., Sommer, I. E. C., Woodruff, P.,
& Daher-Nashif, S. (2022). Psychotic-like experiences
among university female students in Qatar: A
qualitative-phenomenological study. Frontiers in
Psychiatry, 13, Article 988913. https://doi.org/10.3389/fpsyt.2022.988913
Gill,
K., Percival, C., Roes, M., Arreaza, L., Chinchani, A., Sanford,
N., Sena, W., Mohammadsadeghi, H., Menon, M., Hughes, M.,
Carruthers, S., Sumner, P., Woods, W., Jardri, R., Sommer, I.
E., Rossell, S. L., & Woodward, T. S. (2022).
Real-Time Symptom Capture of Hallucinations in Schizophrenia
with fMRI: Absence of Duration-Dependent Activity.
Schizophrenia Bulletin Open, 3(1),
Article sgac050. https://doi.org/10.1093/schizbullopen/sgac050
Grootens,
K. P., & Sommer, I. E. (2022). Redesigning
phase 3 and 4 trials to adopt shared decision making.
The Lancet. Psychiatry, 9(2),
101-103. https://doi.org/10.1016/S2215-0366(21)00385-0
Borkent,
J., Ioannou, M., Laman, J.
D., Haarman, B. C. M., & Sommer, I.
E. C. (2022). Role of the gut microbiome in three
major psychiatric disorders. Psychological
Medicine, 52(7), 1222-1242. Article
0033291722000897. https://doi.org/10.1017/S0033291722000897
Puvogel,
S., Alsema, A., Kracht, L.,
Webster, M. J., Weickert, C. S., Sommer, I. E.
C., & Eggen, B. J. L. (2022).
Single-nucleus RNA sequencing of midbrain blood-brain barrier
cells in schizophrenia reveals subtle transcriptional changes with
overall preservation of cellular proportions and phenotypes.
Molecular Psychiatry, 27,
4731–4740. https://doi.org/10.1038/s41380-022-01796-0
Horowitz,
M. A., Moncrieff, J., de Haan, L., Bogers, J. P. A. M.,
Gangadin, S. S., Kikkert, M., Veling,
W., & Sommer, I. E. C. (2022).
Tapering antipsychotic medication: practical
considerations. Psychological
Medicine, 52(1), 32-35. https://doi.org/10.1017/S0033291721003299
Solmi,
M., Estrade, A., Thompson, T., Agorastos, A., Radua, J., Cortese,
S., Dragioti, E., Leisch, F., Vancampfort, D., Thygesen, L. C.,
Aschauer, H., Schloegelhofer, M., Akimova, E., Schneeberger, A.,
Huber, C. G., Hasler, G., Conus, P., Do Cuenod, K. Q., von Kanel,
R., ... Sommer, I. (2022). The collaborative
outcomes study on health and functioning during infection times in
adults (COH-FIT-Adults): Design and methods of an international
online survey targeting physical and mental health effects of the
COVID-19 pandemic. Journal of Affective
Disorders, 299, 393-407. https://doi.org/10.1016/j.jad.2021.07.048
Oomen,
P. P., Gangadin, S. S., Begemann, M. J.
H., Visser, E., Mandl, R. C. W., & Sommer, I. E.
C. (2022). The neurobiological characterization of
distinct cognitive subtypes in early-phase schizophrenia-spectrum
disorders. Schizophrenia Research,
241, 228-237. https://doi.org/10.1016/j.schres.2022.02.006
2021
de
Boer, J. N., Voppel, A. E., Brederoo, S.
G., Schnack, H. G., Truong, K. P., Wijnen, F. N. K.,
& Sommer, I. E. C. (2023). Acoustic speech markers
for schizophrenia-spectrum disorders: a diagnostic and
symptom-recognition tool. Psychological
Medicine, 53(4), 1302–1312. https://doi.org/10.1017/S0033291721002804
Begemann,
M. J. H., Schutte, M. J. L., Van Dellen, E.,
Abramovic, L., Boks, M. P., Van Haren, N. E. M., Mandl, R. C. W.,
Vinkers, C. H., Bohlken, M. M., & Sommer, I. E. C.
(2023). Childhood trauma is associated with reduced frontal
gray matter volume: A large transdiagnostic structural MRI
study. Psychological Medicine,
53(3), 741-749. https://doi.org/10.1017/S0033291721002087
Oomen,
P. P., Begemann, M. J. H., Brand, B.
A., de Haan, L., Veling, W., Koops,
S., van Os, J., Smit, F., Bakker, P. R., van Beveren,
N., Boonstra, N., Gülöksüz, S.,
Kikkert, M., Lokkerbol, J., Marcelis, M.,
Rosema, B.-S., de Beer, F., Gangadin, S.
S., Geraets, C. N. W., ... Sommer, I. E.
C. (2023). Longitudinal clinical and functional
outcome in distinct cognitive subgroups of first-episode psychosis:
a cluster analysis. Psychological
Medicine, 53(6), 2317 - 2327. https://doi.org/10.1017/S0033291721004153
Begemann,
M. J. H., Sommer, I. E., Brand, R. M.,
Oomen, P. P., Jongeneel, A., Berkhout, J., Molenaar, R. E.,
Wielage, N. N., Toh, W. L., Rossell, S. L., & Bell, I. H.
(2022). Auditory verbal hallucinations and childhood trauma
subtypes across the psychosis continuum: a cluster analysis.
Cognitive Neuropsychiatry, 27(2-3).
https://doi.org/10.1080/13546805.2021.1925235
Kirschner,
M., Hodzic-Santor, B., Antoniades, M., Nenadic, I., Kircher, T.,
Krug, A., Meller, T., Grotegerd, D., Fornito, A., Arnatkeviciute,
A., Bellgrove, M. A., Tiego, J., Dannlowski, U., Koch, K.,
Hülsmann, C., Kugel, H., Enneking, V., Klug, M., Leehr, E. J.,
... Modinos, G. (2022). Cortical and subcortical
neuroanatomical signatures of schizotypy in 3004 individuals
assessed in a worldwide ENIGMA study. Molecular
Psychiatry, 27, 1167–1176. https://doi.org/10.1038/s41380-021-01359-9
Karolinska
Schizophrenia Project K, Frangou, S., Modabbernia, A., Williams, S.
C. R., Papachristou, E., Doucet, G. E., Agartz, I., Aghajani, M.,
Akudjedu, T. N., Albajes-Eizagirre, A., Alnaes, D., Alpert, K.,
Andersson, M., Andreasen, N. C., Andreassen, O. A., Asherson, P.,
Banaschewski, T., Bargallo, N., Baumeister, S., ... Wang, L.
(2022). Cortical thickness across the lifespan: Data from
17,075 healthy individuals aged 3-90 years. Human
brain mapping, 43(1), 431-451. https://doi.org/10.1002/hbm.25364
Luykx,
J. J., Loef, D., Lin, B., van Diermen, L., Nuninga, J.
O., van Exel, E., Oudega, M. L., Rhebergen, D., Schouws, S.
N. T. M., van Eijndhoven, P., Verwijk, E., Schrijvers, D.,
Birkenhager, T. K., Ryan, K. M., Arts, B., van Bronswijk, S. C.,
Kenis, G., Schurgers, G., Baune, B. T., ... Rutten, B. P. F.
(2022). Interrogating Associations Between Polygenic
Liabilities and Electroconvulsive Therapy Effectiveness.
Biological Psychiatry, 91(6),
531-539. https://doi.org/10.1016/j.biopsych.2021.10.013
HAMLETT
OPHELIA Consortium, Kikkert, M. J., Veling,
W., de Haan, L., Begemann, M. J. H., de Koning,
M., & Sommer, I. E. (2022). Medication
strategies in first episode psychosis patients: A survey among
psychiatrists. Early intervention in
psychiatry, 16(2), 139-146. https://doi.org/10.1111/eip.13138
de
Boer, J., Corona Hernández, H., Gerritse,
F., Brederoo, S., Wijnen, F., & Sommer, I.
E. C. (2022). Negative content in auditory verbal
hallucinations: a natural language processing approach.
Cognitive Neuropsychiatry, 27(2-3),
139–149. https://doi.org/10.1080/13546805.2021.1941831
Hjelmervik,
H., Craven, A. R., Johnsen, E., Kompus, K., Bless, J. J.,
Sinkeviciute, I., Kroken, R. A., Løberg, E. M., Ersland, L.,
Grüner, R., Sommer, I. E., & Hugdahl, K.
(2022). Negative valence of hallucinatory voices as predictor
of cortical glutamatergic metabolite levels in schizophrenia
patients. Brain and Behavior,
12(1), Article e2446. https://doi.org/10.1002/brb3.2446
Koops,
S., Brederoo, S. G., de Boer, J.
N., Nadema, F. G., Voppel, A. E., &
Sommer, I. E. (2022). Speech as a Biomarker for
Depression. Cns & neurological disorders-Drug
targets, 22(2), 152 - 160. https://doi.org/10.2174/1871527320666211213125847
Karolinska
Schizophrenia Project K, Dima, D., Modabbernia, A., Papachristou,
E., Doucet, G. E., Agartz, I., Aghajani, M., Akudjedu, T. N.,
Albajes-Eizagirre, A., Alnaes, D., Alpert, K., Andersson, M.,
Andreasen, N. C., Andreassen, O. A., Asherson, P., Banaschewski,
T., Bargallo, N., Baumeister, S., Baur-Streubel, R., ... Wang, L.
(2022). Subcortical volumes across the lifespan: Data from
18,605 healthy individuals aged 3-90 years. Human
brain mapping, 43(1), 452-469. https://doi.org/10.1002/hbm.25320
2020
Karolinska
Schizophrenia Project (KaSP) consortium, Wierenga, L. M., Doucet,
G. E., Dima, D., Agartz, I., Aghajani, M., Akudjedu, T. N.,
Albajes-Eizagirre, A., Alnaes, D., Alpert, K. I., Andreassen, O.
A., Anticevic, A., Asherson, P., Banaschewski, T., Bargallo, N.,
Baumeister, S., Baur-Streubel, R., Bertolino, A., Bonvino, A., ...
Wang, L. (2022). Greater male than female variability in
regional brain structure across the lifespan.
Human brain mapping, 43(1), 470-499.
https://doi.org/10.1002/hbm.25204
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