Stress and reward: Long term cortisol exposure predicts the strength of sexual preference

High perceived stress is associated with decreased sensory-specific satiety in humans

Previous studies have shown that chronic stress increases food intake. One possible mechanism may be due to altered sensory-specific satiety (SSS) among people with high level of chronic stress. In the current study, seventy-six participants were divided into either high-stress or low-stress groups according to their Perceived Stress Scale (PSS) scores. Participants were assigned to consume one of two foods (banana milk and corn soup) ad libitum until they felt comfortably satiated. Before and after eating, participants rated their liking and wanting for the flavor and the odor (via retronasal and orthonasal routes) of the eaten and uneaten foods. Individual interoceptive sensibility and eating behavior were measured using the Multidimensional Assessment of Interoceptive Awareness (MAIA) and Reasons Individuals Stop Eating Questionnaire (RISE-Q-15), respectively. Compared to the low-stress group, the high-stress group demonstrated blunted SSS to the whole food flavor. No significant difference was found for olfactory-specific satiety (retronasal or orthonasal) between the two groups. In addition, across the whole sample of participants, MAIA total score was positively associated with the magnitude of SSS (r = 0.29, p = 0.01). These results indicate that chronic perceived stress may play a role in the experience of reward during eating.

Effect of Tai Chi on Young Adults with Subthreshold Depression via a Stress-Reward Complex: A Randomized Controlled Trial

BACKGROUND

Subthreshold depression is a highly prevalent mood disorder in young adults. Mind-body exercises, such as Tai Chi, have been adopted as interventions for clinical depressive symptoms. However, the possible effect and underlying mechanism of Tai Chi on subthreshold depression of young individuals remain unclear. This randomized controlled study aimed to evaluate the effects of Tai Chi training and tested the combined stress and reward circuitry model for subthreshold depression.

RESULTS

A total of 103 participants completed this trial, with 49 in the 12-week 24-style Tai Chi group and 54 participants in control group. Our results showed significantly lower scores on depressive symptoms (P = 0.002) and anxiety symptoms (P = 0.009) and higher scores on quality of life (P = 0.002) after Tai Chi training. There were significant reductions in salivary cortisol levels (P = 0.007) and putamen gray matter volume (P < 0.001) in the Tai Chi group. The changes in cortisol levels and putamen gray matter volume had direct (bootstrapping confidence interval [- 0.91, - 0.11]) and indirect effects (bootstrapping confidence interval [- 0.65, - 0.19]) on the changes induced by Tai Chi training on depressive symptoms, respectively.

CONCLUSION

The stress-reward complex results indicated an interaction between lowering stress levels and increasing reward circuitry activity associated with the alleviation of depressive symptoms among participants. The 12-week Tai Chi training was effective in improving the symptoms and quality of life of young adults with subthreshold depression. Trial Registration Chinese Registry of Clinical Trials (Registration Number: ChiCTR1900028289, Registered December 12, 2019).

Environmental Contributions to Anhedonia

Anhedonia is a core feature of psychopathological conditions that have recent exposure to stress and trauma as central to their etiology. Indeed, evolutionary accounts of depression suggest that decreased motivation to pursue reward may be an adaptive strategy in the face of social stress, in particular, as it may serve to defuse interpersonal conflict. Through a review of rodent models and research with humans, we show that exposure to stress, particularly when it is chronic, repeated, and/or involves themes of social rejection or defeat, is consistently associated with reduced hedonic capacity ("liking"), motivation to pursue reward ("wanting"), and ability to learn from reward ("reward learning"). Further, across rodent and human research, there is evidence that females show greater stress-induced blunting of reward processing than males. In humans, this sex difference emerges most strongly when examining individual differences in the stress response rather than group differences in stress exposure. We discuss the implications of these findings for understanding the etiology of, and sex differences in, stress-related psychopathology, including depression and addiction.

Cortisol reactivity to stress predicts behavioral responsivity to reward moderation by sex, depression, and anhedonia

Depression is associated with blunted reactivity to acute stress, as well as blunted responsivity to rewards. However, the extent to which responses to stress are associated with responses to reward in individuals meeting criteria for a depressive disorder is unknown. The goal of this study was to examine the relation of responses to stress and reward, and to determine if this relation is moderated by depression diagnosis, anhedonia, and sex. Participants included 114 adults (68 depressed, 46 non-depressed; 75% women) recruited from the community. Stress reactivity was operationalized as the total salivary cortisol output to the Trier Social Stress Test (TSST; Kirschbaum et al., 1993). Response bias to monetary reward was assessed following the TSST recovery period with a probabilistic reward task (PRT; Pizzagalli et al., 2005). In men only, total cortisol output during the TSST was more strongly positively associated with response bias to reward across the three blocks of the PRT. In addition, among depressed participants with high levels of anhedonia, higher cortisol output during the TSST was significantly associated with higher overall response bias to reward. We suggest that in men, the stress and reward systems may both respond quickly, and resolve rapidly, in the face of acute stress. Further, in depression, our findings suggest that anhedonia may represent a specific phenotype in which the stress and reward systems are particularly tuned together.

The Modulatory Role of Cortisol in the Regulation of Sexual Behavior in Young Males

The proneness to be sexually aroused, to perform sexual acts, or to be sexually disinhibited during a particular mood varies across individuals. However, the physiological mechanisms underlying this specific and variable relationship between mood and sex-related processes are poorly understood. We propose that cortisol may act as an important moderator in this as it has shown to influence sexual arousal and to play a neuromodulatory role during emotion regulation. Here, we conducted a functional magnetic resonance imaging study in a sample of young males to investigate whether cortisol modulates the neural response during the approach of sexual stimuli in an approach-avoidance task and whether this potential relationship explains the individual differences in sexual inhibition and in mood-related sexual interest and activity. We revealed that cortisol associates with the anteromedial prefrontal cortex activation during the approach towards sexual stimuli. Moreover, this anteromedial prefrontal cortex response was dependent on individual differences in sexual inhibition and the improvements of negative mood as a result of sexual activity. The anteromedial prefrontal cortex is already known to process bottom-up information, reward, and risk estimation. The neuromodulatory role of cortisol within this region during sexual approach may represent a previously unknown yet key element in the regulation of sexual behavior in young males.

Acute stress enhances pupillary responses to erotic nudes: Evidence for differential effects of sympathetic activation and cortisol

Chronic stress attenuates reproductive behavior in many species, but evidence regarding the impact of acute stress on human sexual arousability is insufficient. Stressor-specific effects might result from divergent roles of both stress response systems. Social self-threat, linked to affiliation-oriented coping, might also influence sexual responsivity. To investigate stress-induced modulation of the processing of sexual cues and its relationship with cortisol, 58 participants underwent either a predominantly sympathetic stressor (3 min sustained handgrip) or similar control procedure. In both conditions, half of the sample was monitored by an opposite-sex person (social evaluation). Pupillary responses to erotic nudes were recorded and dissociated into fast and slow PCA components. Physically stressed participants showed enhanced (slow) dilation to explicit pictures. Cortisol levels after stress negatively predicted rapid responses to opposite-sex and (marginally) explicit stimuli. Our results suggest that acute sympathetic stress exposure facilitates cognitive sexual processing, whereas subsequent HPA-axis activation may induce counteracting effects.

Stress potentiates decision biases: A stress induced deliberation-to-intuition (SIDI) model

Humans often make decisions in stressful situations, for example when the stakes are high and the potential consequences severe, or when the clock is ticking and the task demand is overwhelming. In response, a whole train of biological responses to stress has evolved to allow organisms to make a fight-or-flight response. When under stress, fast and effortless heuristics may dominate over slow and demanding deliberation in making decisions under uncertainty. Here, I review evidence from behavioral studies and neuroimaging research on decision making under stress and propose that stress elicits a switch from an analytic reasoning system to intuitive processes, and predict that this switch is associated with diminished activity in the prefrontal executive control regions and exaggerated activity in subcortical reactive emotion brain areas. Previous studies have shown that when stressed, individuals tend to make more habitual responses than goal-directed choices, be less likely to adjust their initial judgment, and rely more on gut feelings in social situations. It is possible that stress influences the arbitration between the emotion responses in subcortical regions and deliberative processes in the prefrontal cortex, so that final decisions are based on unexamined innate responses. Future research may further test this 'stress induced deliberation-to-intuition' (SIDI) model and examine its underlying neural mechanisms.