@phdthesis{Forster2023, author = {Forster, Andr{\´e}}, title = {Targeting Temporally Stable Vulnerability Factors in the Prediction of Long-Term Courses of Depression: Diagnostic Considerations and Therapeutic Protocols Based on Transcranial Ultrasonic Neuromodulation of Endophenotypes}, doi = {10.25972/OPUS-27906}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-279065}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2023}, abstract = {Depressive disorders represent one of the main sources for the loss of healthy years of life. One of the reasons for this circumstance is the recurrent course of these disorders, which can be interrupted by current therapeutic approaches, especially in the shortterm, but seem to be maintained at least in part in the long-term. Subsequently, on one hand, this thesis deals with methodological measurement issues in the longitudinal prediction of depressive courses. On the other hand, it addresses two currently discussed neuroscience-based treatment approaches, which are investigated experimentally in a basic-psychological manner and reviewed in the light of their potential to translate results to the application in patient care. These two approaches each address potential mechanisms that may negatively impact long-term disease trajectories: First, stable endophenotypes for vulnerability factors that could regain control over the organism and reactivate maladaptive experiences, or behaviors with increasing temporal distance from therapeutic methods are focused on. In the studies presented, these were influenced by a recently rediscovered method of neuromodulation (transcranial low-intensity focused ultrasound) which is discussed in light of its unique capability to address even deepest, subcortical regions at a high spatial resolution. Lastly, as a second approach, an experimental design for the use of reconsolidation interference is presented, which could provide a first insight into the applicability of corresponding protocols in the field of depressive disorders and thus contribute to the modification, instead of inhibition, of already mentioned endophenotypes. In sum, methodological considerations for monitoring and predicting long-term courses of depression are deducted before two approaches are discussed that could potentially exert positive influences on the recurrent nature of depressive symptoms on their own, in combination with each other, or as augmentation for existing therapeutic procedures.}, subject = {Depression}, language = {en} } @article{ZiebellRodriguesForsteretal.2023, author = {Ziebell, Philipp and Rodrigues, Johannes and Forster, Andr{\´e} and Sanguinetti, Joseph L. and Allen, John JB. and Hewig, Johannes}, title = {Inhibition of midfrontal theta with transcranial ultrasound explains greater approach versus withdrawal behavior in humans}, series = {Brain Stimulation}, volume = {16}, journal = {Brain Stimulation}, number = {5}, doi = {10.1016/j.brs.2023.08.011}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-349890}, pages = {1278-1288}, year = {2023}, abstract = {Highlights • Transcranial ultrasound neuromodulation/stimulation (TUS) is a growing field. • We conducted a double-blind sham-controlled within-subjects large sample TUS study. • Right prefrontal cortex TUS inhibits midfrontal theta electroencephalography (MFT). • TUS MFT inhibition explains greater approach versus withdrawal in a virtual T-maze. • This distinct TUS-MFT-behavior link merits future basic and applied research. Abstract Recent reviews highlighted low-intensity transcranial focused ultrasound (TUS) as a promising new tool for non-invasive neuromodulation in basic and applied sciences. Our preregistered double-blind within-subjects study (N = 152) utilized TUS targeting the right prefrontal cortex, which, in earlier work, was found to positively enhance self-reported global mood, decrease negative states of self-reported emotional conflict (anxiety/worrying), and modulate related midfrontal functional magnetic resonance imaging activity in affect regulation brain networks. To further explore TUS effects on objective physiological and behavioral variables, we used a virtual T-maze task that has been established in prior studies to measure motivational conflicts regarding whether participants execute approach versus withdrawal behavior (with free-choice responses via continuous joystick movements) while allowing to record related electroencephalographic data such as midfrontal theta activity (MFT). MFT, a reliable marker of conflict representation on a neuronal level, was of particular interest to us since it has repeatedly been shown to explain related behavior, with relatively low MFT typically preceding approach-like risky behavior and relatively high MFT typically preceding withdrawal-like risk aversion. Our central hypothesis is that TUS decreases MFT in T-maze conflict situations and thereby increases approach and reduces withdrawal. Results indicate that TUS led to significant MFT decreases, which significantly explained increases in approach behavior and decreases in withdrawal behavior. This study expands TUS evidence on a physiological and behavioral level with a large sample size of human subjects, suggesting the promise of further research based on this distinct TUS-MFT-behavior link to influence conflict monitoring and its behavioral consequences. Ultimately, this can serve as a foundation for future clinical work to establish TUS interventions for emotional and motivational mental health.}, language = {en} } @article{HaberstumpfForsterLeinweberetal.2022, author = {Haberstumpf, Sophia and Forster, Andr{\´e} and Leinweber, Jonas and Rauskolb, Stefanie and Hewig, Johannes and Sendtner, Michael and Lauer, Martin and Polak, Thomas and Deckert, J{\"u}rgen and Herrmann, Martin J.}, title = {Measurement invariance testing of longitudinal neuropsychiatric test scores distinguishes pathological from normative cognitive decline and highlights its potential in early detection research}, series = {Journal of Neuropsychology}, volume = {16}, journal = {Journal of Neuropsychology}, number = {2}, doi = {10.1111/jnp.12269}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-318932}, pages = {324 -- 352}, year = {2022}, abstract = {Objective Alzheimer's disease (AD) is a growing challenge worldwide, which is why the search for early-onset predictors must be focused as soon as possible. Longitudinal studies that investigate courses of neuropsychological and other variables screen for such predictors correlated to mild cognitive impairment (MCI). However, one often neglected issue in analyses of such studies is measurement invariance (MI), which is often assumed but not tested for. This study uses the absence of MI (non-MI) and latent factor scores instead of composite variables to assess properties of cognitive domains, compensation mechanisms, and their predictability to establish a method for a more comprehensive understanding of pathological cognitive decline. Methods An exploratory factor analysis (EFA) and a set of increasingly restricted confirmatory factor analyses (CFAs) were conducted to find latent factors, compared them with the composite approach, and to test for longitudinal (partial-)MI in a neuropsychiatric test battery, consisting of 14 test variables. A total of 330 elderly (mean age: 73.78 ± 1.52 years at baseline) were analyzed two times (3 years apart). Results EFA revealed a four-factor model representing declarative memory, attention, working memory, and visual-spatial processing. Based on CFA, an accurate model was estimated across both measurement timepoints. Partial non-MI was found for parameters such as loadings, test- and latent factor intercepts as well as latent factor variances. The latent factor approach was preferable to the composite approach. Conclusion The overall assessment of non-MI latent factors may pose a possible target for this field of research. Hence, the non-MI of variances indicated variables that are especially suited for the prediction of pathological cognitive decline, while non-MI of intercepts indicated general aging-related decline. As a result, the sole assessment of MI may help distinguish pathological from normative aging processes and additionally may reveal compensatory neuropsychological mechanisms.}, language = {en} }