All psychiatric disorders, with exceptions according to the following criteria: dementia (all forms, e.g. F00–F03), severe intellectual disability (IQ 25) (for olfactory reasons), anosmia (complete loss of sense of smell).
Conditions
Interventions
Group 1: The observational group consists of participants from the Q01 subproject of TRR 379 ("Service Project: Recruitment and biotyping transdiagnostic risk mechanisms for aggressive behaviors in me
Sponsors
Uniklinik Aachen
Eligibility
Sex/Gender
All
Age
18 Years to 40 Years
Inclusion criteria
Inclusion criteria: Odor donors: Male, Between 18 - 55 years old, Caucasian (white), German speaking, Healthy non-smokers without medication or drug use. Donors are asked to refrain from activities that could affect their body odor (e.g. spicy food, alcohol, garlic and asparagus) for 2 days prior to donation. Odor recipients: 18 - 40 years of age
Exclusion criteria
Exclusion criteria: Odor donors (behavioral study): Regular medication or drug use, metabolic diseases (e.g. diabetes mellitus, thyroid dysfunction, hormonal disorders), psychology students or people with increased understanding of psychological tasks and tests, smokers, diagnosed psychiatric diseases, neurological diseases Odor recipients (MRI study): dementia, severe mental retardation (IQ 25) the normal range, as being underweight or overweight is associated with poorer olfactory sensitivity, frequent nosebleeds or nosebleeds within the last 3 days, chronic nasal diseases, respiratory diseases, chronic sinusitis, anosmia, lung diseases, diseases with CNS involvement, smoking, head injuries, head surgery, metabolic diseases (diabetes, thyroid), other diseases (such as hepatitis, renal insufficiency, gastrointestinal ulcers), as well as the usual MRI exclusion criteria (metal implants, pacemaker, claustrophobia). For healthy controls, additional current and previous psychiatric illnesses, drug abuse or regular use of medication
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| The study is divided into two parts: 1) the odor donation, where the odors are collected, and 2) the main study (odor exposure). The primary endpoint refers to the main study (odor exposure). Primary endpoint: The primary endpoint of the study is the hyperreactivity of the amygdala and insula in highly aggressive patients compared to less aggressive patients and healthy controls during exposure to ABOs. Timing and assessment of the primary endpoint: This endpoint is assessed during the fMRI session. The measurement takes place at the time when the participants are exposed to the different odor conditions (ABO, neutral body odor, odorless air). Neural activity in the amygdala and insula is recorded using functional magnetic resonance imaging (fMRI). Possible other ROIs may still be defined. Measurement procedure: The activity of the amygdala and insula is analyzed based on fMRI data. In addition, before and after odor exposure, the participants rate the intensity and pleasantness of the presented odors using visual analogue scales. In order to distinguish between aggression- and stress-related responses, physiological stress markers (cortisol, testosterone) as well as subjective self-reports of emotional states (e.g., by standardized questionnaires) are also collected. Hypothesis: During stimulation with aggression-related body odors, we expect that highly aggressive patients, compared to less aggressive patients and controls, will show hyperreactivity of the amygdala and insula. The analysis is carried out under control of potential covariates (e.g., stress level). Comment: During the odor donation, the primary objective is to collect aggression-related body odors (ABOs). In order to validate the odor samples, it is necessary to assess both physiological and psychological parameters. It is possible that, after exposure, participants may not exclusively report an increased aggression level, but possibly, for example, primarily an increased stress level. In this | — |
Secondary
| Measure | Time frame |
|---|---|
| 2. During the PPS injuries in the VR experiment, we expect that the closer the threatening avatar is, the greater the physiological response (indicated by heart rate and skin conductance as well as higher subjective threat ratings) will be. We expect these effects of physiological arousal to be amplified when the avatar enters the PPS. 3. Higher physiological responses are expected in the presence of the ABO, which will influence the PPS (longer distances, earlier responses). 4. Factors such as the gender of the recipient, level of aggression, and type/number of early traumas will modulate behavioral and physiological responses to the ABO. 5. Limbic hyperreactivity to PPS injury and during the VTA task will be enhanced by ABO. We expect limbic hyperreactivity to be associated with weaker involvement of prefrontal areas, modulated by trauma, gender, aggression level and other covariates. a) Across both tasks, we expect hyperreactivity in the limbic areas and a lower degree of coupling to the network processing social cues, including the frontal areas. b) Highly aggressive patients will respond more strongly to ABO. In the VTA task, ABO stimulation will bias responses to neutral and ambiguous stimuli towards threat, while passive observation of the PPS will be associated with a stronger limbic response in this patient. c) The response pattern of both fMRI tasks will provide the opportunity to identify a specific aggressive biosignature within AMD. The central signature will mainly be a limbic hyperfunction potentially associated with or exacerbated by trauma. 6. Using dynamic causal modeling (DCM) and multivariate pattern analysis (MVPA), different patterns of amygdala activity during odor-enhanced stimulation without visual stimulation will help to a) identify individuals with increased aggression and distinguish them from other groups and b) predict responses in the patient groups to both PPS injury and during VTA. | — |
Countries
Germany
Contacts
Public ContactChristoph Mallmann
Klinik für Psychiatrie, Psychotherapie und Psychosomatik, RWTH Aachen
Outcome results
None listed