Tim Ziermans

Contact Details

Cognitive Development lab
Karolinska Insitute
Department of Neuroscience
Retzius Väg 8
171 77 Stockholm
Sweden

Tel.: +46  (0)8 524 86 394
E-mail: tim.ziermans@ki.se

Curriculum Vitae Tim Ziermans

Tim Ziermans (Utrecht, the Netherlands) graduated from high school in 1998 and after a year abroad at the University of Louisiana at Lafayette, attended the University of Amsterdam (UvA) to study psychology. In 2004 he obtained his MSc degree in clinical psychology with a specialization in neuropsychology. The title of his masters thesis was: Facial affect recognition in Klinefelters syndrome (47, XXY). After graduation he joined Sarah Durston's neuroimaging lab at the department of Child & Adolescent Psychiatry, University Medical Center in Utrecht. He finished his PhD in september 2010 and is currently employed as a postdoctoral researcher at the Karolinska Instute in Sweden

UMC Research Project

Neurobiological vulnerability markers in adolescents at risk of psychosis.

The focus of my PhD project was on structural MRI (volumetric & VBM) and neurophysiological (ERP, EMG, EOG) measures in young adolescents at risk of psychosis. These measures were analyzed both cross-sectionally and longitudinally. Baseline data have shown that there were no gross structural brain abnormalities in young adolescents at risk compared to typical controls. However, follow-up data showed that individuals who continued to develop psychosis, displayed more pronounced structural brain changes (smaller total brain volume, white matter volume decrease and accelerated thinning of the cortex in the left hemisphere) than individuals who did not become psychotic and controls. This suggests that brain changes related to the clinical manifestation of psychosis are progressive and can be detected around the time of onset.

On a neurophysiological level, four classical schizophrenia markers were examined. Only prepulse inhibition (PPI) was able to discriminate between both groups. These data suggest that neurobiological markers of schizophrenia that are also present (to a lesser extent) in adult at-risk patients, are relatively unaffected in young adolescents at risk. When PPI was studied over a 2-year time-period, reduced PPI for UHR individuals was found to be more robust statistically, but did not appear to be related to subsequent onset of psychosis.

List of Publications

  • Ziermans TB, Schothorst PF, van Engeland H. Transition and remission in adolescents at ultra-high risk for psychosis. Schizophrenia Research, in press.
  • Ziermans TB, Schothorst PF, Schnack HG, Koolschijn PCMP, Kahn RS, van Engeland H, Durston S. Progressive structural brain changes during development of psychosis. Schizophrenia Bulletin, in press.
  • Ziermans TB, Schothorst PF, Magnée MJCM, van Engeland H, Kemner C. Reduced prepulse in adolescents at risk for psychosis: A 2-year follow-up study, in press.
  • Ziermans TB, Durston, S, Sprong M, Nederveen H, van Haren NEM, Schnack H, Lahuis BE, Schothorst, PFvan Engeland H. No evidence for structural brain changes in young adolescents at risk for psychosis. Schizophrenia Research, 112(1-3):1-6.
  • Durston S, Fossella JA, Mulder, MJ, Casey, BJ, Ziermans, TB, Vessaz, MN, van Engeland H: Dopamine-transporter genotype interacts with familial risk for Attention-Deficit/Hyperactivity Disorder and striatal activity (2008). Journal of the American Academy of Child & Adolescent Psychiatry, 47(1), 61-67.
  • Durston S, Mulder M, Casey BJ, Ziermans T, van Engeland, H (2006): Activation in Ventral Prefrontal Cortex is Sensitive to Genetic Vulnerability for Attention-Deficit Hyperactivity Disorder. Biological Psychiatry, 60(10):1062-1070.
  • Sprong M, Becker HE, Schothorst PF, Swaab H, Ziermans TB, Dingemans PM, Linszen D, van Engeland H (2008): Pathways to psychosis: A comparison of the pervasive developmental disorder subtype Multiple Complex Developmental Disorder and the "At Risk Mental State". Schizophrenia Research, 99(1-3), 38-47.
  • Van Rijn S, Aleman A, Sonneville L, Sprong M, Ziermans T, Schothorst P, van Engeland H, Swaab H (2010). Misattribution of facial expressions of emotion in adolescents at increased risk of psychosis: the role of inhibitory control. Psychological Medicine, 27, 1-10.
  • Van Rijn S,  Schothorst P, van 't Wout M, Sprong M, Ziermans TB, van Engeland H, Aleman A, Swaab H. Affective dysfunctions in adolescents at risk for psychosis: Emotion awareness and social functioning. Psychiatry Research, In press.
  • Van Rijn S, Aleman A, Sonneville L, Sprong M, Ziermans T, Schothorst P, van Engeland H, Swaab H. Neuroendocrine markers of high risk for psychosis: Salivsary testosterone in adolescent boys with prodromal symptoms

Submitted / In Preparation

  • Ziermans TB, Schothorst PF, Sprong M, Magnée MJCM, van Engeland H, Kemner C. Reduced prepulse inhibition as an early vulnerability marker of the psychosis prodrome in adolescence. In revision.
  • Schothorst PF, Ziermans TB, Sprong M, van Rijn S, Lahuis B, van Engeland H, Swaab H. Neurocognitive performance of young adolescents at ultra-high risk for psychosis. Submitted.
  • Dumontheil I, Roggeman C, Ziermans, T, Peyrard-Janvid M, Matsson H, Kere J, Klingberg T. Influence of the COMT genotype on working memory and brain activity changes during development. Resubmitted.