prof. dr. I.E.C. (Iris) Sommer

prof. dr. I.E.C. (Iris) Sommer

Full Professor
prof. dr. I.E.C. (Iris) Sommer
  • Psychiatry

Research Programs




Iris Sommer obtained her PhD in 2004 cum laude on language lateralization in schizophrenia. After she finished her psychiatry residencies she worked as a psychiatrist in UMCU where she started the Voices Clinic. She started a research group investigating the pathophysiology of hallucinations and developed an interest in the treatment of schizophrenia.

She has several positions in editorial boards and committees:

  1. Elected member of the Young Academy of the Royal Dutch Academy of Arts and Science (DJA of KNAW)
  2. Invited member of AcademiaNet (500 leading women in science), headed by Angela Merckel
  3. Associate editor at Schizophrenia Bulletin (neuro-imaging section),
  4. Chair of the Dutch ZonMW program "Memorabel", part of the Deltaplan Dementie
  5. Member of the International Advisory Council SIRS (Schizophrenia International Research Society), 
  6. Member of the Steering Committee of the International Consortium on Hallucination Research
  7. Chair of the Scientific Committee of the Dutch Psychiatry Association 
  8. Member of the Dutch Committee for Research Integrity (Landelijk Orgaan Wetenschappelijke Integriteit)
  9. Member of the KNAW (Royal Dutch Academy of Arts and Sciences) Jury of the Heineken Medicine Price 
  10. Member of the KNAW (Royal Dutch Academy of Arts and Sciences) Committee KNAW-agenda large-scale research facilities (grootschalige onderzoeksfaciliteiten)

Research line

Pathophysiology and treatment of psychosis

Most recent key publications

1: Sommer IE, de Kort GA, Meijering AL, Dazzan P, Hulshoff Pol HE, Kahn RS, van Haren NE. How Frequent Are Radiological Abnormalities in Patients With Psychosis? A Review of 1379 MRI Scans. Schizophr Bull, 2012 Mar 13, Epub ahead of print
2: Sommer IE, de Witte L, Begemann M, Kahn RS. Nonsteroidal anti-inflammatory drugs in schizophrenia: ready for practice or a good start? A meta-analysis. J Clin Psychiatry, 2012 73(4):414-419.
3: Sommer IE, Slotema CW, Daskalakis J, Derks EM, Blom JD, van der Gaag M. The treatment of hallucinations in schizophrenia Schizophrenia Bulletin, 2012 Jun;38(4):704-14
4: Howes O, Shotbold PJ, Daalman K, Diederen KMJ, Kahn RS, Sommer IE. Dopaminergic function in the psychosis spectrum: an [18F]-DOPA imaging study in healthy individuals with auditory hallucinations. Schizophrenia Bulletin 2012 January 26
5: Sommer IE, Aleman A, Slotema CM, Schutter DJ. Transcranial stimulation for psychosis: the relationship between effect size and published findings. Am J Psychiatry, 2012 169(11):1211

Fellowship and Awards

2005 Veni ZONMW € 200,000, nr. 916.56.172
2008 Clinical Fellowship ZonMW €160,000, nr. 40-00703-97-270
2009 Vidi, ZonMW €800,000, nr. 017.106.301 
2012: Stanley foundation USA, $491,000 12T-008
2012: Stanley foundation USA, $475,000, and 12T-009

Research Output (300)

Author Correction: Functional connectome differences in individuals with hallucinations across the psychosis continuum

Schutte Maya J L, Bohlken Marc M, Collin Guusje, Abramovic Lucija, Boks Marco P M, Cahn Wiepke, Dauwan Meenakshi, van Dellen Edwin, van Haren Neeltje E M, Hugdahl Kenneth, Koops Sanne, Mandl René C W, Sommer Iris E C 14 apr 2021, In: Scientific Reports. 11 1 p.

The role of depression in the prediction of a "late" remission in first-episode psychosis:An analysis of the OPTiMiSE study

Fraguas David, Díaz-Caneja Covadonga M, Pina-Camacho Laura, Winter van Rossum Inge, Baandrup Lone, Sommer Iris E, Glenthøj Birte, Kahn René S, Leucht Stefan, Arango Celso 7 apr 2021, In: Schizophrenia Research. 231 , p. 100-107 8 p.

The effect of prednisolone on symptom severity in schizophrenia:A placebo-controlled, randomized controlled trial

Nasib Lyliana G, Gangadin Shiral S, Rossum Inge Winter-van, Boudewijns Zimbo S R M, de Witte Lot D, Wilting Ingeborg, Luykx Jurjen, Somers Metten, Veen Natalie, van Baal Caroline, Kahn René S, Sommer Iris E 9 mrt 2021, In: Schizophrenia Research. 230 , p. 79-86 8 p.

Simvastatin Augmentation for Patients With Early-Phase Schizophrenia-Spectrum Disorders:A Double-Blind, Randomized Placebo-Controlled Trial

Sommer Iris E, Gangadin Shiral S, de Witte Lot D, Koops Sanne, van Baal C, Bahn Sabine, Drexhage Hemmo, van Haren N E M, Veling Wim, Bruggeman R, Martens Peter, Wiersma Sybren, Veerman Selene R T, Grootens Koen P, van Beveren Nico, Kahn Rene S, Begemann Marieke J H 20 feb 2021, In: Schizophrenia bulletin. 47 , p. 1108-1115 8 p.

Functional connectome differences in individuals with hallucinations across the psychosis continuum

Schutte Maya J L, Bohlken Marc M, Collin Guusje, Abramovic Lucija, Boks Marco P M, Cahn Wiepke, Dauwan Meenakshi, van Dellen Edwin, van Haren Neeltje E M, Hugdahl Kenneth, Koops Sanne, Mandl René C W, Sommer Iris E C 13 jan 2021, In: Scientific Reports. 11 13 p.

Language in schizophrenia:relation with diagnosis, symptomatology and white matter tracts

de Boer J N, van Hoogdalem M, Mandl R C W, Brummelman J, Voppel A E, Begemann M J H, van Dellen E, Wijnen F N K, Sommer I E C 1 dec 2020, In: npj Schizophrenia. 6

Symptom Remission and Brain Cortical Networks at First Clinical Presentation of Psychosis:The OPTiMiSE Study

Dazzan Paola, Lawrence Andrew J, Reinders Antje A T S, Egerton Alice, van Haren Neeltje E M, Merritt Kate, Barker Gareth J, Perez-Iglesias Rocio, Sendt Kyra-Verena, Demjaha Arsime, Nam Kie W, Sommer Iris E, Pantelis Christos, Wolfgang Fleischhacker W, van Rossum Inge Winter, Galderisi Silvana, Mucci Armida, Drake Richard, Lewis Shon, Weiser Mark, Martinez Diaz-Caneja Covadonga M, Janssen Joost, Diaz-Marsa Marina, Rodríguez-Jimenez Roberto, Arango Celso, Baandrup Lone, Broberg Brian, Rostrup Egill, Ebdrup Bjørn H, Glenthøj Birte, Kahn Rene S, McGuire Philip, 15 okt 2020, In: Schizophrenia bulletin. 47 , p. 444-455 12 p.

Functional brain networks in the schizophrenia spectrum and bipolar disorder with psychosis

van Dellen Edwin, Börner Corinna, Schutte Maya, van Montfort Simone, Abramovic Lucija, Boks Marco P., Cahn Wiepke, van Haren Neeltje, Mandl René, Stam Cornelis J., Sommer Iris 2 sep 2020, In: npj Schizophrenia. 6

Vasogenic edema versus neuroplasticity as neural correlates of hippocampal volume increase following electroconvulsive therapy

Nuninga Jasper O., Mandl René C.W., Froeling Martijn, Siero Jeroen C.W., Somers Metten, Boks Marco P., Nieuwdorp Wendy, Heringa Sophie, Sommer Iris E.C. 1 jul 2020, In: Brain Stimulation. 13 , p. 1080-1086 7 p.

Prednisolone versus placebo addition in the treatment of patients with recent-onset psychotic disorder:A trial design

Nasib Lyliana G., Sommer Iris E., Winter - Van Rossum Inge, De Vries Jacqueline, Gangadin Shiral S., Oomen Priscilla P., Judge Gurmeet, Blom Renske E., Luykx Jurjen J., Van Beveren Nico J.M., Veen Natalie D., Kroken Rune A., Johnsen Erik L. 8 jun 2020, In: Trials. 21 , p. 1-13

All research output

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