Stress-related sleep disturbance and polysomnographic response to caffeine

Abstract

Background and purpose-To determine the sleep response to caffeine in individuals vulnerable to stress-related sleep disturbance as measured by polysomnography.Patients and methods-Eleven healthy individuals without insomnia scoring low (4 women, mean age=32.64 ± 15.46 years) and 10 healthy individuals also without insomnia scoring high (6 women, mean age=34.20 ± 13.73 years) on a measure of vulnerability to stress-related sleep disturbance were studied in a laboratory protocol. A moderate-low dose of caffeine (3 mg/kg) was administered 1 h prior to lights-out and compared to a counterbalanced control night with each condition separated by 1 week. Standard polysomnographic measures were assessed (i.e. total sleep time, sleep efficiency, latency to persistent sleep, and sleep stage percentages) for both control and caffeine nights.Results-There were no between-group differences in sleep on the control night. Importantly, individuals reporting vulnerability to stress-related sleep disturbance had significantly prolonged latency to persistent sleep in response to the caffeine challenge (interaction; P <0.05).Conclusion-Normal sleepers with an identified vulnerability to stress-induced sleep disturbance exhibited greater objectively verifiable sleep-reactivity in response to a caffeine challenge compared to non-vulnerable individuals. These results suggest that the construct of individual differences in vulnerability to sleep disturbance applies to a pharmacological 'stressor' (i.e. caffeine) as well as to previously assessed stressors such as a first-night effect. This finding provides further support for generalized trait vulnerability by demonstrating a sleep disturbance to a wake-promoting pharmacological challenge in specific a priori identified individuals.

Psychometric Evaluation of the Ford Insomnia Response to Stress Test (FIRST) in Early Pregnancy

“…14,15 Despite the increased use of the FIRST questionnaire to assess stressrelated sleep reactivity in men and non-pregnant women, 14,16,17 the instrument has not, to our knowledge, been used to assess BRIEF SUMMARY Current Knowledge/Study Rationale: The Ford Insomnia Response to Stress Test (FIRST) questionnaire has emerged as a broadly used instrument that assesses individual's vulnerability to situational insomnia under stressful conditions. Despite the increased use of the FIRST questionnaire to assess stress-related sleep reactivity in men and non-pregnant women, the instrument has not been used to assess stress-related sleep reactivity in pregnant women.…”

“…21 Consistent with prior studies in the present study, we used the median score (12) to define high and low FIRST score groups. 16,[21][22][23][24] Patient Health Questionnaire-9 (PHQ-9)…”

“…Women were assigned to 1 of 5 depressive symptom categories based on total PHQ-9 score: (a) no depressive symptoms (0-4); (b) mild (5-9); (c) moderate (10)(11)(12)(13)(14); (d) moderately severe (15)(16)(17)(18)(19); and (e) severe (20)(21)(22)(23)(24)(25)(26)(27) depressive symptoms. For the purpose of this study, we defined presence of antepartum depression based upon total PHQ-9 score, (a) no depressive symptoms (0-9) and (b) antepartum depression (10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27). 25 A meta-analysis of 14 studies supports the use of a PHQ-9 score of ≥ 10 to classify subjects with major depressive disorder.…”

Effects of caffeine on sleep and cognition

“…It was found that feeling tired in the morning induced high caffeine use which was associated with subsequent impaired sleep, indicating that cause and effect concerning the relation between caffeine and impaired sleep is not always clear. Another factor that may induce sleep disturbance in interaction with caffeine is vulnerability to stress (Drake et al, 2006). Drake and colleagues showed that individuals with an objectively identified vulnerability to stress-induced sleep disturbance showed a stronger sleep-reactivity in response to a 3-mg/kg BW caffeine challenge than nonvulnerable individuals.…”

Temporal Stability of the Ford Insomnia Response to Stress Test (FIRST)

“…Based on the trait theory, 17 traits differ across people, affect behavior, and importantly, are stable patterns (in behavior, cognitions, and emotions) of habit over time. Though current evidence indicates sleep reactivity indeed differs across individuals (i.e., with varying levels of vulnerability in experiencing situational insomnia), 6,11 negatively affects sleep under stressful conditions (e.g., longer sleep onset latency, nocturnal arousals), 9,12,18 and is associated with maladaptive behaviors (e.g., sleep-interfering behaviors), 19 cognitions (e.g., rumination, dysfunctional sleep beliefs), and emotions (e.g., emotion-oriented coping), 1,20,21 evidence of its temporal stability is lacking (i.e., whether the FIRST is reliably stable over time? ).…”