Thesis defence in the University of Oulu

Doctoral Candidate

PhD (Psychology) Aino Saarinen

Faculty and research unit

University of Oulu Graduate School, Faculty of Medicine, Research Unit of Clinical Neuroscience

Field of study

Medicine

Date and time of the thesis defence

4.6.2020 12:00

Place of the thesis defence

Remote access: https://helsinki.zoom.us/j/64703053332?pwd=VjdOVC9hV0Yzd0hVYjR0eEMrQStidz09

Topic of the dissertation

Is psychosis risk associated with structural or functional abnormalities in the brain?

Opponent

Professor Erkki Isometsä, University of Helsinki

Custos

Professor Niklas Ravaja, University of Helsinki

Is psychosis risk associated with structural or functional abnormalities in the brain?

In the doctoral thesis, it was obtained that the first-degree relatives of schizophrenia patients have abnormalities in the frontal lobe of the brain that is related to self-control. Additionally, it was obtained that psychosis risk is related to higher level of physiological fluctuation in the brain that may refer to such a signal source that has not been measured in most previous studies.

In the doctoral thesis, it was investigated whether the healthy relatives of schizophrenia patients have structural or functional abnormalities in the brain. The meta-analysis included altogether more than 1600 relatives of schizophrenia patients and more than 1700 healthy controls. Relatives of schizophrenia patients did not have any structural alterations in the gray matter volume. Instead, relatives of schizophrenia patients had functional abnormalities in the frontal gyrus of the brain that is related to e.g. self-control and behavioral regulation.

In Finland, individuals at risk for psychosis have been provided with so-called cognitive remediation programs where the individuals train e.g. working memory and concentration skills and, thus, aim to promote their every-day functioning. On the basis of this doctoral thesis, these cognitive remediation programs could focus on attentional processes and self-control.

Moreover, in the dissertation, it was found that psychosis risk (psychotic symptoms) is linked to increased physiological fluctuation in the brain. Physiological fluctuation refers to fluctuation that derives from e.g. blood vessel pulsations, respiratory processes and circulation of cerebrospinal fluid. Physiological fluctuation may also be derived from the glymphatic system that acts as the "cleaning system" of the brain. In individuals at risk for psychosis, increased physiological fluctuation was obtained in such brain regions that have not been found to be affected when using more traditional analyzing methods of brain-imaging data. This indicates that the novel method (focus on physiological fluctuation) may reach such abnormalities in the brain that have not been obtained using traditional analyzing methods. Previous research evidence has shown that psychotic patients have a variety of cardiovascular diseases that may remain without treatment in the health care and that shorten the life expectancy of psychotic patients. This dissertation suggests that psychotic patients may have alterations in cardiovascular functioning also in the brain.

In the dissertation, we used the Northern Finland Birth Cohort 1986 data that includes a representative sample of the individuals born in 1986 in the Northern Finland.

The substudies of the thesis have been published in Schizophrenia Research and Psychiatry Research: Neuroimaging.

 

Dissertation

Last updated: 1.6.2020