Hasler Group

Stress- und Depressionsforschung

Zur Person

Prof. Dr. med. Gregor Hasler ist Psychiater, Psychotherapeut und Neurowissenschaftler. Er untersucht mittels bildgebenden Verfahren wie MRI, PET und EEG das Hirn von Menschen mit Stress-abhängigen psychischen Störungen. Neben seiner wissenschaftlichen Tätigkeit engagiert er sich für die Vermittlung von medizinisch-psychologischem Fachwissen. Er hat folgende, allgemein verständliche Bücher für verfasst:

  • Resilienz: Der Wir-Faktor: Gemeinsam Stress und Ängste überwinden. Schattauer-Verlag, 2016 (Nachdruck 2018)
  • Die Darm-Hirn-Connection: Revolutionäres Wissen für unsere psychische und körperliche Gesundheit. Schattauer-Verlag, Juni 2019.

Er gibt an nationalen und internationalen Veranstaltung zu Gesundheitsthemen Vorträge, unter anderem am Präventionstag des Kantons Zürich, am Gottlieb-Duttweiler Institut, Rüschlikon, am Swiss eHealth Forum, an den Schweizer Gesundheitstagen etc. Er trägt regelmässig zu Veröffentlichungen in Zeitungen und Zeitschriften bei, einschliesslich NZZ am Sonntag, Süddeutsche Zeitung, FAZ und Beobachter. Im Jahr 2018 hat der Tagesanzeiger ein Portrait über ihn veröffentlicht.

  • Research

    The main research focus of the Hasler group is molecular neuroimaging of the glutamate and GABA neurotransmitter systems in affective disorders, including depression and bipolar disorder. We are building up our research on our previous work on reduced glutamate and GABA concentrations in the prefrontal cortex of depressed individuals. Currently, we are studying the effects of ketamine in unipolar and bipolar depression. Ketamine is antidepressant with rapid and robust effects, targeting the glutamate system. In a large cohort study, we measure glutamate, glutamine and GABA in the general population as correlate of depression vulnerability and as predictors of affective disorders. We use multimodal imaging to examine prefrontal glutamate concentrations using MRI, fMRI and in combination with PET imaging on the metabotropic glutamate receptor 5 in bipolar depression.

Projects

  • Glutamatergic System

    All conventional antidepressant drugs affect the neurotransmitters serotonin and norepinephrine. However, recent studies show that drugs affecting the messenger glutamate demonstrate a stronger and faster effect compared to conventional drugs. In a series of studies, we have demonstrated that the glutamate system is changed in patients with depression. These changes are believed to be the reason for the strong effect of glutamate drugs. In particular, Ketamine shows a strong antidepressant effect. Therefore, we started to use Ketamine at our ambulatory clinic (Bolligenstrasse) for the treatment of severe depression using specific treatment guidelines. The aim of our research is to evaluate the efficacy and safety of this treatment. In addition, we use magnetic resonance spectroscopy to assess glutamate, glutamine and GABA in a community based-cohort study, and apply multimodal imaging on the glutamate system (glutamate, glutamine, mGluR5 PET) to elucidate the pathogenesis of bipolar depression and early phases of psychosis.

  • Paralysis of the frown lines

    In recent years, three randomized, placebo-controlled studies have found a surprisingly large antidepressant effect in the paralysis of frown lines of the forehead by Botulinum toxin A (Botox) in depression. The average response rate was 54 percent. We plan to offer this treatment at our ambulatory clinic (Bolligenstrasse). In a scientific study, we want to determine why this therapy is so effective. The paralysis may lead to a suppression of negative emotions. We plan to investigate this through psychological experiments and EEG measurements. Further, the inhibited expression may improve social interactions. We plan to investigate this with regular, short smartphone-surveys. We will also consider whether the aesthetic effect strengthens the self-esteem of the depressive patient. The findings of this study will contribute to an optimal use of botulinum toxin A in depression.

  • Impartial understanding of social behavior

    Recent studies regarding the career outcomes of depressed people show that disruptive social behavior can be more decisive than classic depressive symptoms such as the depressive mood and sadness that usually occur only temporarily. Until now, there have been no simple, effective  methods to reliably measure social behavior. Hence, the knowledge of the treatment of social behavior disorders is very low. In a series of studies using simple experiments based on behavioural economics, we have examined the social behaviors of depressive patients and patients with personality disorders. We have shown that, even after the amelioration of depressive symptoms, patients tend to avoid competitive situations. However, questionnairs have shown that this avoidance correlates with depressive symptoms. In follow-up studies, we aim to make our behavioural social-measurement methods more accurate by additionally using brain imaging techniques. Our approch is highly innovative, since investigation of neural networks involved in competition avoidance of patients with depression has not been attempted before. Our final aim is developing therapeutic strategies to treat competition avoidance, so that the patients will increase their chances for better employment chances and competitive jobs.

  • Testing of anti-stigma campaigns

    The majority of the population have a rather negative opinion about depression, leading to shame in people who suffer depression. This leads to inadequate treatment and difficulties during job-related reintegration. The stigma against depression is often implicit (an unconscious, automatic behavior). Previous anti-stigma campaigns did not show any improvement. To the contrary, they may have led to worsening outcomes. To clarify the effects of anti-stigma campaigns, we develop methods to measure implicit effects. This methodology will allow us to psychologically test campaigns before their general application.

  • Biomarkers

    Leading experts agree that the discovery of biomarkers for mental disorders is of paramount importance to promote psychiatric research. Biomarkers are objective diagnostic indicators that improve diagnoses and facilitate the choice of therapies. Today different medications, psychotherapies, and treatment settings must be tested until the optimal therapy is found. Biomarkers help shorten this therapy-setting-process. Furthermore, biomarkers may help to develop new therapies that are specifically tailored to disease processes.
     
    The greatest scientific success of our group in recent years has been the discovery of a glutamate receptor, mGluR5, as a biomarker for nicotine dependence. Using emission tomography, we showed that the amount of this receptor is 30 percent lower in a smoker’s brain. After more than five years of abstinence, the level of the receptor normalizes. A slow recovery of the receptor predicts a high recidivism rate. These findings inspired Novartis to investigate drugs targeting mGluR5 for addiction therapy.
     
    In a series of studies, we have developed biomarkers that predict responses to conventional antidepressants. Our method allows researchers to determine whether a serotonin deficiency, a norepinephrine deficiency, or both are present. We were able to show the significance of these biomarkers in depression and in bulimia.
     
    In an ongoing study, we are measuring a possible lack of dopamine as a biomarker for schizophrenia. The development of this biomarker will allow to selectively adjust antipsychotic drugs throughout the disease process.
     
    In a large project (in collaboration with the University of Zurich and the Epigenetics Laboratory at the Mount Sinai School of Medicine in New York), we evaluate epigenetic alterations as biomarkers for mental disorders in the general population. Epigenetics refers to the modification of genes by environmental factors. Such markers allow us to better understand the role of social and genetic factors in the development of mental disorders. The results may help uncover efficient preventive and therapeutic measures.

Kontakt

Prof. Dr. med. Gregor Hasler

Ordentlicher Professor
Psychiatrie und Psychotherapie

Chefarzt
Freiburger Netzwerk für Psychische Gesundheit

Chemin du Cardinal-Journet 3
1752 Villars-sur-Glâne

  gregor.hasler@unifr.ch
+41 26 304 16 89