Ivan Vargas

Differential associations between childhood trauma subtypes and adolescent HPA-axis functioning

UNLABELLED Studies examining the association between childhood trauma exposure and neuroendocrine functioning have returned inconsistent findings. To date, few studies have accounted for the role exposure to different types of childhood trauma may have on different neuroendocrine adaptations, and no study has examined this association using multiple indices of hypothalamic-pituitary-adrenal axis (HPA-axis) functioning. The purpose of this study was to characterize the unique associations between exposure to physical abuse, emotional abuse, and non-intentional trauma, and multiple indices of HPA-axis functioning. METHODS A community sample of 138 youth (aged 9-16) completed the Socially Evaluated Cold Pressor Task (SE-CPT) while their parents completed the Early Trauma Inventory (ETI). All youth then collected 4 diurnal salivary cortisol samples at home across 2 consecutive weekdays. RESULTS High reported exposure to non-intentional trauma was associated with intact diurnal regulation but elevated cortisol at bedtime, physical abuse was associated with faster reactivity to acute stress, and emotional abuse was associated with delayed recovery of cortisol following acute stress. Taken together, there was a heterogeneous relationship among different indices of HPA-axis functioning and trauma subtype. DISCUSSION Different types of childhood trauma exposure are related to distinct anomalies in HPA-axis functioning. This study underscores the importance of research incorporating multiple indices of HPA-axis functioning to inform our understanding of the underlying neuroendocrine dysregulation that may later lead to stress-related psychopathology.

Facebook use and depressive symptomatology

The popularity of social networking sites, such as Facebook, has increased rapidly over the past decade, especially among youth. Consequently, the impact of Facebook use on mental health problems (e.g., depressive symptomatology) has become a recent area of concern. Yet, evidence for such a link has been mixed and factors that contribute to heterogeneity of findings have not been identified. In this study, we examined whether the association between Facebook use and depressive symptoms is moderated by individual factors (i.e., personality and sex). To this end, we measured Facebook use, depressive symptoms, and personality domains (i.e., extroversion and neuroticism) among 237 young adults. No direct association was found between Facebook use and depressive symptoms. However, for females with high neuroticism, more frequent Facebook use was associated with lower depressive symptoms. Our findings suggest a complex relationship between Facebook use and depressive symptomatology that appears to vary by sex and personality. Facebook use may be protective against depressive symptoms for female users with high levels of neuroticism, while Facebook use may be unrelated to depressive symptoms among males.

Dissecting the impact of sleep and stress on the cortisol awakening response in young adults.

Cortisol rises precipitously upon awakening, in what has been called the cortisol awakening response (CAR). Atypical CARs have been linked to a number of negative health outcomes. Yet, our understanding of the possible mechanisms creating these associations remains unclear. Both stress and sleep can influence CAR, and may potentially explain its links to health. However, these factors also impact each other, and their influence on CAR has rarely been studied simultaneously. In order to differentiate their effects, this study examined the impact of daily life hassles, anticipatory stress, and subjectively reported sleep on CAR among 58 college students. Self-reported stress and sleep, as well as salivary cortisol (collected during the first hour after awakening) were obtained across two consecutive days. Total sleep time predicted CAR magnitude, but daily hassles and anticipatory stress did not after accounting for the effect of sleep. Lower total sleep time was associated with lower awakening cortisol and greater CAR. These results provide further evidence for the impact of sleep insufficiency on CAR, and suggest future efforts to use CAR as a stress biomarker should take the impact of sleep into consideration.

Age of Trauma Onset and HPA Axis Dysregulation Among Trauma‐Exposed Youth

The hypothalamic-pituitary-adrenal axis (HPA axis) is a pathway through which childhood trauma may increase risk for negative health outcomes. The HPA axis is sensitive to stress throughout development; however, few studies have examined whether timing of exposure to childhood trauma is related to differences in later HPA axis functioning. Therefore, we examined the association between age of first trauma and HPA axis functioning among adolescents, and whether these associations varied by sex. Parents of 97 youth (aged 9-16 years) completed the Early Trauma Inventory (ETI), and youth completed the Socially-Evaluated Cold-Pressor Task (SECPT). We measured salivary cortisol response to the SECPT, the cortisol awakening response, and diurnal regulation at home across 2 consecutive weekdays. Exposure to trauma during infancy related to delayed cortisol recovery from peak responses to acute stress, d = 0.23 to 0.42. Timing of trauma exposure related to diverging patterns of diurnal cortisol regulation for males, d = 0.55, and females, d = 0.57. Therefore, the HPA axis may be susceptible to developing acute stress dysregulation when exposed to trauma during infancy, whereas the consequences within circadian cortisol regulation may occur in the context of later trauma exposure and vary by sex. Further investigations are warranted to characterize HPA axis sensitivity to exposure to childhood trauma across child development.

Quantitative Measures of Nocturnal Insomnia Symptoms Predict Greater Deficits Across Multiple Daytime Impairment Domains

This study examined the associations between reported quantitative sleep measures and multiple daytime impairment domains. We collected data from a subsample of adults (n = 513) from the Colorado Longitudinal Twin Study and Community Twin Study. Results revealed that greater insomnia symptom frequency (days per week) significantly predicted greater global sleep-related functional impairment and depressive symptoms. Sleep onset latency was also positively associated with depressive symptoms. Receiver operating characteristic curve analyses indicated 3–4 nights per week and 36–40 min provided optimal sensitivity and specificity for impairment. Thus, insomnia frequency and sleep latency are critical in understanding the impact of insomnia on multiple impairment domains. Using functional impairment as criterion, these findings also support the use of specific quantitative cutoffs for sleep measures in diagnostic systems.

Trait and state rumination interact to prolong cortisol activation to psychosocial stress in females

There is a growing realization that cognitive processes associated with stress coping, such as rumination and distraction, can impact the hypothalamic-pituitary-adrenal-axis (HPA-axis). Yet, little is known about what aspects of the HPA-axis stress response (rate of activation, duration of activation, rate of recovery) is impacted by such cognitive processes. This study examines the impact of both ruminative trait tendencies and experimentally induced rumination on salivary cortisol responses to a social evaluative stress task. Participants (n=71) were exposed to the Trier Social Stress Test (TSST) and were then randomized to complete either a rumination or distraction task. Trait rumination was also assessed at baseline. Results showed no main effects of either trait rumination or experimental condition, but they interacted to predict the cortisol response. Specifically, participants high in trait rumination had prolonged duration of cortisol activation in the rumination condition, compared to those in the distraction condition. In contrast, cortisol responses of participants with low trait rumination did not differ by condition. Notably, our interaction effect was only significant in females. Our findings highlight the complex relationship between rumination and HPA-axis activity, suggesting an interaction of trait and state rumination in shaping HPA-axis responses to stress, and call attention to sex differences in this relationship.

The Cortisol Awakening Response and Depressive Symptomatology: The Moderating Role of Sleep and Gender

The association between depression and the cortisol awakening response (CAR) has been widely examined, yet the results are mixed and factors responsible for such inconsistencies are poorly understood. The current study investigated whether the link between depressive symptomatology and CAR varied as a function of two such factors: sleep and gender. The sample included 58 young adults (30 females; Mage  = 18.7; SDage  = 0.91). Participants completed the Beck Depression Inventory as well as the Consensus Sleep Diary to assess depressive symptomatology and daily sleep patterns, respectively. Participants also provided four salivary cortisol samples (0, 30, 45 and 60 min after awakening) during two consecutive weekdays. Results demonstrated that greater depressive symptoms were associated with a greater CAR but only when depressive symptoms were linked to a shorter sleep time. In addition, gender significantly moderated the association between depressive symptoms and CAR. While greater depressive symptoms were associated with an elevated CAR among females, they were associated with a blunted CAR among males. These findings provide some insight into potential mechanisms linking depressive symptomatology and CAR, and suggest that future studies examining CAR as a biomarker of depression should account for differences in sleep and gender. Copyright

The cortisol awakening response after sleep deprivation: Is the cortisol awakening response a “response” to awakening or a circadian process?

This study tested whether the cortisol awakening response is dependent on the transition from sleep to awakening, or alternatively, a circadian-driven process that is independent of awakening. A total of 40 participants were randomly assigned to either a total sleep deprivation or a sleep condition. Salivary cortisol was also assessed. Participants in the sleep condition demonstrated a traditional cortisol awakening response, whereas participants in the total sleep deprivation condition showed no increases in morning cortisol. These results are consistent with the notion that if circadian-driven processes are related to the cortisol awakening response, they may only be activated when awakening occurs or is anticipated.

HPA-axis activation as a key moderator of childhood trauma exposure and adolescent mental health

Individual differences in a child’s sensitivity to stress may influence whether youth exposed to trauma develop symptoms of psychopathology. We examined the interaction between HPA-axis reactivity to an acute stressor and exposure to different types of childhood trauma as predictors of mental health symptoms in a sample of youth. Youth (n = 121, ages 9–16; 47% female) completed a standardized stress task, including 5 post-stress salivary cortisol samples. Parents also completed the Child Behavior Checklist as a measure of child internalizing and externalizing symptoms in the past month, and completed the Early Trauma Inventory (ETI) as a measure of their child’s trauma exposure. More emotional abuse and non-intentional trauma were associated with greater internalizing symptoms. Youth exposed to physical abuse who demonstrated slower HPA-axis reactivity had elevated internalizing and externalizing symptoms. Youth exposed to emotional abuse or non-intentional traumatic events who demonstrated faster HPA-axis reactivity had elevated internalizing and externalizing symptoms. Profiles of exaggerated or attenuated HPA-axis reactivity to acute stress may be risk factors for psychopathology in children facing different stressful social environments.