Stress and Behaviour

Everyone knows how it feels to be stressed. The ability to cope with stress has become more important over the years. Impaired stress regulation can have profound effects on health, cognition, and behaviour via its impact on the brain. This research line focusses on three major topics:

  • 1.) Vulnerability factors (biogenetic, cognitive, and environmental) on stress responsiveness and the onset/development of stress-related psychopathology

  • 2.) The role of stress in habitual and addictive behavior

  • 3.) The influence of stress on memory control

Vulnerability factors (biogenetic, cognitive, and environmental) on stress responsiveness and the onset/development of stress-related psychopathology

This research line dives into the intricate connections between biological, cognitive, and environmental factors and their collective impact on how we respond to stress, ultimately influencing the emergence of stress-related issues such as depression, sleep disturbances, and eating problems. The negative effects of everyday stress on the risk factors for depression aren't isolated incidents but depend on a combination of cognitive and genetic vulnerabilities. For instance, having a predisposition towards neuroticism, combined with a specific genetic makeup (S’S 5HTTLPT), heightens the impact of daily stressors on the risk of depression (Markus, 2013).

Additionally, our research delves into the intriguing possibility that changes in food and diet might influence the likelihood of developing stress-related disorders, particularly in individuals already grappling with a combination of genetic-brain and cognitive stress vulnerability factors. In our exploration, we've uncovered encouraging evidence suggesting that foods enhancing serotonin (5-HT) levels can have positive effects on stress-related behaviors. For instance, these dietary interventions show promise in improving emotional-eating habits, reducing stress responsiveness, and enhancing sleep quality (Schepers et al., 2019).

The primary goal of this research endeavor is to identify the key players in the intricate dance of stress that significantly impacts our mental well-being.

The role of stress in habitual and addictive behavior

This research line is driven by models that portray addictive behavior as a response triggered automatically by everyday stimuli associated with that particular behavior. Imagine seeing a pack of cigarettes and feeling an immediate urge to light one. This behavior seems to be even more pronounced in situations of acute stress.

One of our focusses lies in understanding the role of dopamine in stress-induced habitual behavior, as outlined in our study by van Ruitenbeek et al. in 2021. However, it's essential to note that this shift towards habitual behavior under stress doesn't consistently play out in laboratory settings, as shown by studies conducted by Quaedflieg and colleagues in 2019 and a replication study by Smeets et al. in 2023.

Currently, our efforts are directed towards identifying potential reasons why stress may not always enhance addictive behavior. Our hypothesis is that it may be linked to the various methods used to measure addictive behavior. It's an ongoing exploration aimed at uncovering the nuances of this intricate relationship between stress and addictive tendencies.

The influence of stress on memory

Stress can make the bad seem worse. This third research line focusses on factors that improve and impair intentional forgetting.

Our findings highlight a key player in this process – the stress-associated hormone cortisol. We investigated the role of cortisol in hindering intentional forgetting, in studies by Ashton et al. 2023 and Quaedflieg et al. 2022. Pinpointing to specific brain areas, namely the prefrontal and parietal regions, as the neural mechanisms underlying this phenomenon (Quaedflieg et al. 2020).

Furthermore, when intentional suppression is impaired, it can lead to an increased frequency of intrusive thoughts, disrupting daily functioning. This insight is supported by research of Ashton et al. 2020. Interestingly, our registered report suggests that mindfulness might hold the key to enhancing our ability to control unwanted thoughts. This, in turn, becomes crucial for emotional regulation and overall mental well-being, as outlined in Ashton et al. 2023. The ultimate goal is to develop new strategies that alter how memories are recalled in order to build resilience.

  • 148 healthy participants completed a 10-day app-based mindfulness training or an active control task. At baseline, inhibitory control and working memory were assessed as measures of executive functioning.

  • Here, we tested whether acute stress may disrupt the intentional control of memory and, if so, through which neural mechanism. We exposed healthy men and women to a stress (n = 27) or control (n = 26) procedure before they aimed repeatedly to retrieve some previously learned cue-target pairs and to actively suppress others.

  • It is unclear, however, whether these deficits are a direct consequence of the acute stress-induced cortisol response. The present study was designed to examine the stress-induced impairment in suppression-induced forgetting in a subgroup of cortisol responders.

  • The aim of this study was to gain insight into the mechanism underlying stress-induced impairments in intentional suppression of intrusions by investigating the combined and independent roles of the two major stress hormones, noradrenaline and cortisol.

  • Acute stress is thought to reduce goal-directed behaviour, an effect purportedly associated with stress-induced release of catecholamines. In contrast, experimentally increased systemic catecholamine levels have been shown to increase goal-directed behaviour.

  • The current study explored associations between 3-months accumulated HCC and the tendency to ruminate about negative events in 27 S/S and 27 L/L 5-HTTLPR-carriers (screened from a large n = 827 DNA database).

  • The current study therefore examines the interaction between the 5-HTTLPR genotype, impact of life events, and trait neuroticism on depression symptoms.

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