Measuring the Psychobiological Correlates of Daily Experience in Adolescents.

Mapping the psychobiological correlates of social contexts, experiences, and emotional responses of adolescents in their daily lives provides insight into how adolescent well-being shapes, and is shaped by, experience. Measures of these psychobiological correlates are enabled by devices and technologies that must be precise and suitable for adolescent participants. The present report reviews the most often used research measures, and suggests strategies for best practice, drawn from practical experience. The rapid advances in technological methods to collect attuned measures of psychological processes, social context, and biological function indicate the promise for multimodal measures in ecological settings. Attaining these methodological goals will support research to secure comprehensive, quality data, and advance the understanding of psychobiological function in ambulatory settings.

The cortisol awakening response in relation to objective and subjective measures of waking in the morning.

Studies of the salivary cortisol awakening response (CAR) may be confounded by delays between waking in the morning and obtaining the 'waking' salivary sample. We used wrist actigraphy to provide objective information about waking time, and studied the influence of delays in taking the waking sample on the CAR. Eighty-three men and women (mean age 61.30 years) who were referred to hospital with suspected coronary artery disease were studied. Saliva samples were obtained on waking and 15 and 30 min later. The mean interval between waking defined by actigraphy and reported waking time was 6.12+/-(S.D.) 14.8 min, with 55.4% having no delay. The waking saliva sample was obtained an average 5.78+/-15.0 min after self-reported waking, and 12.24+/-20.3 min after objective waking. The waking cortisol value was significantly higher in participants who had a delay between waking and sampling >15 min (mean 14.46+/-6.34 nmol/l) than in those with zero (mean 10.45+/-6.41 nmol/l) or 1-15 min delays (mean 11.51+/-5.99 nmol/l, p=0.043). Cortisol did not increase between 15 and 30 min after waking in those who delayed >15 min. There were no differences in CAR between participants with zero and 1-15 min delays from objectively defined waking to reported sample times. A small proportion (14.7%) of participants who did not delay saliva sampling showed no increase in cortisol over the 30 min after waking. These CAR nonresponders did not differ from the remainder on sleep patterns, waking time, clinical or medication characteristics, but were more likely to be of higher socioeconomic status (p=0.009). We conclude that long delays between waking and obtaining 'waking' cortisol samples will lead to misleading CAR results, but that delays up to 15 min may not be problematic. A small minority of individuals do not show a positive CAR despite not delaying saliva sampling after waking.

Assessment of the cortisol awakening response: Expert consensus guidelines.

The cortisol awakening response (CAR), the marked increase in cortisol secretion over the first 30-45 min after morning awakening, has been related to a wide range of psychosocial, physical and mental health parameters, making it a key variable for psychoneuroendocrinological research. The CAR is typically assessed from self-collection of saliva samples within the domestic setting. While this confers ecological validity, it lacks direct researcher oversight which can be problematic as the validity of CAR measurement critically relies on participants closely following a timed sampling schedule, beginning with the moment of awakening. Researchers assessing the CAR thus need to take important steps to maximize and monitor saliva sampling accuracy as well as consider a range of other relevant methodological factors. To promote best practice of future research in this field, the International Society of Psychoneuroendocrinology initiated an expert panel charged with (i) summarizing relevant evidence and collective experience on methodological factors affecting CAR assessment and (ii) formulating clear consensus guidelines for future research. The present report summarizes the results of this undertaking. Consensus guidelines are presented on central aspects of CAR assessment, including objective control of sampling accuracy/adherence, participant instructions, covariate accounting, sampling protocols, quantification strategies as well as reporting and interpreting of CAR data. Meeting these methodological standards in future research will create more powerful research designs, thus yielding more reliable and reproducible results and helping to further advance understanding in this evolving field of research.

Frequent nightmares are associated with blunted cortisol awakening response in women.

Nightmares are relatively common sleep complaints that seem to be associated with affective distress. To date, few attempts have been made to link nightmares to the biological markers of the stress response, and the HPA response in particular. The present study examined the relationship between frequent nightmares and the cortisol awakening response (CAR) in a cross-sectional study of working women (N=188). Analysis revealed that those who reported frequent nightmares (N=13) showed a blunted CAR on a working day, compared to those who did not report nightmares. This result was independent of psychiatric symptoms, demographic variables, and lifestyle. Our preliminary findings suggest that decreased HPA reactivity might be a trait-like feature of women with frequent nightmares.

Chronotype and diurnal cortisol profile in working women: differences between work and leisure days.

The influence of chronotype on the diurnal profile of salivary cortisol was examined in a sample of 187 healthy women: 21 evening chronotype, 24 morning chronotype and 142 intermediate chronotype. Saliva samples were collected at waking, 30 min post-awakening, at 1000 h, 1200 h, 1500 h, 1700 h and at bedtime on one work and one leisure day. Several components of the diurnal profile were examined including the cortisol awakening response, the total cortisol output and the diurnal profile on both the work and the leisure day, a significant main effect of time emerged (both p<0.01). After adjustment for age, smoking status, self-rated health, time of waking, and sleep problems, no effect of chronotype was evident for cortisol in the evening, the cortisol awakening response, or total cortisol output over the working day. However, on the leisure day, total cortisol output was greater in evening-types than intermediate or morning-types, after adjustment for covariates (p=0.029). The present data indicate that chronotype has a limited impact on the diurnal cortisol profile of healthy women, and may be somewhat impervious to individual preferences for morning or evening activity.

Cortisol and alpha amylase reactivity and timing of puberty: vulnerabilities for antisocial behaviour in young adolescents.

The theoretical framework proposed that cortisol and saliva alpha amylase (sAA) reactivitiy are vulnerabilities for antisocial behaviour. These indices of hypothalamic-pituitary-adrenal (HPA) and sympathetic-adrenal-medulary (SAM) components of the stress system, respectively, were considered vulnerabilities that also interact with the putative stressful transition of timing of puberty to predispose adolescents toward antisocial behaviour. The sample consisted of 8- to-13-year-old boys and girls (N=135) and a parent. For boys, timing of puberty moderated the association between cortisol and sAA reactivity and antisocial behaviour. Higher cortisol reactivity in later timing boys was related to a composite index of antisocial behaviour and rule-breaking behaviour problems. In contrast, lower sAA reactivity and earlier timing of puberty in boys was related to rule breaking and conduct disorder symptoms. The interaction between timing of puberty and HPA or SAM regulation and timing of puberty in boys suggests that reproductive, neuroendocrine mechanisms may be involved in the extensively documented adverse consequences of off-time pubertal development.

The stress response in adolescents with inattentive type ADHD symptoms.

OBJECTIVE: To investigate the hypothalamic pituitary adrenal (HPA) axis response to a stressor in adolescents with inattentive type attention-deficit hyperactivity disorder symptoms (ADHD-I). METHOD: Salivary cortisol was measured in threshold inattentive (TI, n = 7), moderately inattentive (MI, n = 13) and no symptom (comparison) (n = 19) groups of healthy, young adolescents, based on symptom counts, prior to and after an induced social/cognitive stressor. RESULTS: The TI group displayed a significant decrease in cortisol post stressor whereas both the MI and comparison groups showed an increase in cortisol. CONCLUSION: The diagnostic threshold of inattentive type ADHD shows HPA axis dysregulation whereas the more mild form does not show dysfunction.