A validation study of the Occupational Depression Inventory in Poland and Ukraine.

This study examined the psychometric and structural properties of the Polish and Ukrainian versions of the Occupational Depression Inventory (ODI). We relied on two samples of Polish employees (NSample1 = 526, 47% female; NSample2 = 164, 64% female) and one sample of Ukrainian employees (NSample3 = 372, 73% female). In all samples, the ODI exhibited essential unidimensionality and high total-score reliability (e.g., McDonald's omegas > 0.90). The homogeneity of the scale was strong (e.g., 0.59 ≤ scale-level Hs ≤ 0.68). The ODI's total scores thus accurately ranked individuals on a latent occupational depression continuum. We found evidence of complete measurement invariance across our samples, a prerequisite for between-group comparisons involving observed scores. Looking into the criterion validity of the ODI, we found occupational depression to correlate, in the expected direction, with resilience and job-person fit in six areas of working life-workload, control, rewards, community, fairness, and values. The prevalence of occupational depression was estimated at 5% in Sample 1, 18% in Sample 2, and 3% in Sample 3. Our findings support the use of the ODI's Polish and Ukrainian versions. This study adds to a growing corpus of research suggesting that the ODI is a robust instrument.

Study directions and development of cognitive theory of depression. / Kierunki badan i rozwoju poznawczej teorii depresji.

Aaron T. Beck's cognitive model of depression became the basis for the analysis of cognitive factors as significant correlates and predictors of depression. Psychological mechanisms of depression related to the depressive cognitive triad, the specificity of cognitive schemas and errors in cognitive processing determined the directions of further research on depression. The presented analysis of selected studies confirms and extends Beck's assumptions about the role of cognitive factors in the development and maintenance of depressive symptoms. The analysis of psychological, neuroimaging and biochemical studies provides a broader perspective of understanding both the etiology and mechanisms that sustain the symptoms of depression. The development of neuroimaging research has broadened the knowledge about the brain mechanisms of depression - the presented research combine the theoretical constructs of the cognitive concept of depression with the characteristics of the activity of brain structures and their functional connections. The following conclusions seem to be particularly important for clinical practice: 1) impairment of the cognitive inhibition function in depression reduces the control of negative automatic thoughts - strengthening working memory is important; 2) different brain mechanisms for processing rewards and punishments in people suffering from depression and in healthy people explain the formation of self-esteem - this knowledge can be an important element of psychoeducation in therapeutic work; 3) neuroimaging studies indicate neuronal correlates of cognitive distortions observed in depression - for further research on depression, it would be particularly important to monitor changes in brain activity in the course of its treatment.

Exploring Protective Factors in Wellbeing: How Sensory Processing Sensitivity and Attention Awareness Interact With Resilience.

The aim of the study is to analyze the relationship between sensory processing sensitivity (SPS), attention awareness, and resilience and to determine whether attention awareness may moderate the relation between sensitivity and resilience. The sample consisted of 273 adults (239 women; M age=24.12, SD=6.59years). The highly sensitive person scale, the resiliency assessment scale, and the mindful attention awareness scale were used in the study. The results indicate significant relationships between SPS and resilience; emotional reactivity is especially associated with lower resilience, whereas sensing the subtle is associated with higher resilience. The regression analyses revealed that SPS is a significant predictor of resilience, but diverse aspects of sensitivity explain resilience differently. Attentional awareness was found to be a significant moderator that strengthens the positive relationship between sensing the subtle and tolerance of negative emotions. The consequences of high sensitivity include high levels of distress, anxiety, and a sense of overload; therefore, searching for protective factors is important to maintain the wellbeing of highly sensitive people. As one of the characteristics of highly sensitive persons, sensing the subtle may be an important resource that allows to them to deal effectively with difficult situations. Training on attention awareness and conscious presence may be an important way to deal with negative emotions and develop personal competences. The results indicate that these strategies may be of high significance for improving wellbeing and protecting highly sensitive persons against various stress factors.

Individual Differences and Susceptibility to Burnout Syndrome: Sensory Processing Sensitivity and Its Relation to Exhaustion and Disengagement.

The aim of the study is to analyze the relationship between sensory processing sensitivity and occupational burnout. This analysis makes it possible to explore the problem of sensitivity as a predictor of burnout syndrome and to discuss adequate coping strategies in the work environment to improve employee well-being. The sample consists of 516 employees (236 women; M age = 28.97, SD = 6.62 years). The Highly Sensitive Person Scale (HSPS; 27 items) was used to measure sensory processing sensitivity; the Oldenburg Burnout Inventory (OLBI; 16 items) was used to measure exhaustion and disengagement from work. The analysis of sensitivity is based on the 'DOES' model of a highly sensitive person, which includes depth of processing (D), overstimulation (O), emotional reactivity and empathy (E), and sensing the subtle (S). Burnout due to exhaustion and disengagement is analyzed. The factor analysis of the HSPS confirms its three-factor structure. The results indicate significant relationships between sensory processing sensitivity and burnout symptoms. However, the influence of specific aspects of sensitivity on the burnout problem varies: the results indicate that higher emotional reactivity is linked to worse burnout symptoms, but sensing the subtle shows the opposite effect and may be a protective factor against exhaustion. Significant gender differences were observed [F(511,1) = 136.63, p < 0.001; η2 = 0.21]; women revealed a significantly higher level of general sensitivity (M women = 4.66, SD = 0.62) as compared to men (M men = 4.01; SD = 0.64). Awareness of one's high sensory-processing sensitivity and its potential outcomes in the work environment may be essential in order to implement appropriate regulatory strategies. Proactive strategies aimed at reducing prolonged emotional overload may be critical for highly sensitive employees. Recognizing high sensitivity may reduce burnout symptoms and improve well-being at work.

Psychophysiological Characteristics of Burnout Syndrome: Resting-State EEG Analysis.

INTRODUCTION: The consequences of chronic work-related stress are related to various emotional, cognitive, and behavioral symptoms. Occupational burnout as a complex syndrome is characterized by exhaustion, cynicism, and lower professional efficacy. Moreover, the growing amount of research on the neural correlates of burnout broadens the existing knowledge on the mechanisms underlying this syndrome. AIM OF THE STUDY: The aim of the study is to explore possible differences in brain activity between burnout and nonburnout employees. Frequency-specific EEG power analyses in a resting-state condition in burnout subjects and controls are presented. MATERIALS AND METHODS: Burnout employees (N=46; 19 men) were matched with the control group (N=49; 19 men; mean age: 36.14 years, SD=7.89). The Maslach Burnout Inventory-General Survey (MBI-GS) and the Areas of Worklife Survey (AWS) scale were used to measure burnout symptoms and work conditions, respectively. A 256-channel EEG (EGI System 300) was used to collect psychophysiological data. A repeated measures ANOVA was performed with condition (eyes-open vs. eyes-closed) and region (6 levels: extracted scalp regions) factors; burnout (2 levels: burnout vs. no burnout) was the grouping factor. RESULTS: A significant difference was observed only in the alpha frequency band: the burnout group revealed significantly lower alpha power in the eyes-open condition compared to the controls (p<0.05). The correlation analysis revealed that gender may significantly change the pattern of relations between EEG spectral characteristics and burnout symptoms. CONCLUSIONS: Reduced alpha power in burnout individuals suggests cortical hyperactivity and may be related to greater mental effort and the possible development of compensatory mechanisms by burnout subjects.

Occupational burnout and its overlapping effect with depression and anxiety.

OBJECTIVES: The problem of defining burnout concerns its overlapping effect with other syndromes and disorders, such as depression and anxiety. Additionally, some individual characteristics influence susceptibility to burnout (e.g., neuroticism). Therefore, the question arises whether burnout is or is not a distinct syndrome. The aim of the study is to compare 2 distinct burnout measures by analyzing their connections with organizational and individual variables. MATERIAL AND METHODS: The study was conducted in the Institute of Applied Psychology at the Jagiellonian University, Kraków, Poland on a group of employees (N = 100; 40 men; mean age 36.03 years). All participants completed 2 burnout scales: the Maslach Burnout Inventory - General Survey (MBI-GS) and the Link Burnout Questionnaire (LBQ). Organizational and individual factors were controlled with Areas of Worklife Survey, State-Trait Anxiety Inventory, NEO Five-Factor Inventory and Beck's Depression Inventory scales. A structural equation path model was created to quantify the relations between organizational factors and burnout, as well as to control the individual factors of anxiety, neuroticism and depression. RESULTS: The results indicate high compatibility between MBI-GS and LBQ on burnout diagnosis. The MBI-GS and LBQ revealed stronger connections with organizational context and individual characteristics, respectively. Depression explains dimensions of exhaustion (MBI-GS, LBQ), sense of disillusion (LBQ), neuroticism-exhaustion (MBI-GS); anxiety explains sense of professional inefficacy (LBQ). CONCLUSIONS: Besides organizational variables, individual characteristics also play an important role in explaining burnout syndrome. Exploring the 2 burnout models has revealed that depression is an important determinant of exhaustion. Cynicism and relationship deterioration have consistently been explained only by organizational context. Int J Occup Med Environ Health. 2019;32(2):229-44.

Self-Efficacy as a Moderator between Stress and Professional Burnout in Firefighters.

The purpose of the study is to analyze the importance of individual resources in firefighting, one of the highest risk professions. Firefighters from 12 different Polish provinces (N = 580; men; M (mean age) = 35.26 year, SD = 6.74) were analyzed regarding the perceived stress at work, burnout, self-efficacy, and a broad range of sociodemographic variables. The Perceived Stress Scale (PSS), the Link Burnout Questionnaire (LBQ), and the General Self-Efficacy Scale (GSES) were used in the study. To explore the relationships between work-related stress, burnout, and self-efficacy, separate regression models for each burnout dimension were analyzed. The results revealed that self-efficacy is a significant moderator that changes the direction and strength of the relationships between perceived stress and psychophysical exhaustion, sense of professional inefficacy, and disillusion. However, self-efficacy did not moderate the relationship between stress and lack of engagement in relationships (relationship deterioration). The results indicate that self-efficacy in firefighters is a crucial personal resource that buffers the impact of perceived stress on most burnout symptoms. It may be concluded that in high risk professions, special attention should be paid to developing self-efficacy as an important part of burnout prevention programs, pro-health activities, and psychoeducation.

Stimulus, response and feedback processing in burnout - An EEG study.

Professional burnout is a syndrome that is characterized by psychophysical or emotional exhaustion, depersonalization and diminished professional efficacy. Research on burnout often indicates deficits in cognitive functioning, such as memory problems or impaired voluntary control over attention. Many studies focus on behavioral and self-reported measures of burnout consequences; however, a limited number have focused on its consequences on a neural level. In our EEG study (N = 88; 42 with burnout), we analyzed the event-related potentials (ERP) associated with stimulus, response and feedback processing using two experimental procedures - the Go/NoGo Task and the Doors Task. Our results show that while there is no difference in performance between burnout and control group, on the neural level there are significant differences in all analyzed aspects of information processing: stimulus, response and feedback processing, indicated by the N200 and P300, Pe, and P200 event-related potentials, respectively.

Daytime Effect of Monochromatic Blue Light on EEG Activity Depends on Duration and Timing of Exposure in Young Men.

Growing evidence suggests an alerting effect of monochromatic blue light on brain activity. Little is known about the moderation of those effects by timing and duration of exposure. The present electroencephalography (EEG ) study examined such moderations on delta, theta, alpha1, alpha2, and beta EEG bands. A counterbalanced repeated-measures design was applied. The 16-hr daytime period was divided into three sessions: 07:00-12:20, 12:20-17:40, and 17:40-23:00 (timing of exposure). Two light conditions comparable in luminance but differing in wavelength were applied, namely polychromatic white light and monochromatic blue light (460 nm). There were two durations of exposure-the shorter one lasting 30 min and the longer one lasting 4 hrs. Thirty male students participated in the study. Four factors analyses of variance (ANOV As, for light conditions, timing of exposure, duration of exposure, and brain area) were performed on each EEG band. Results indicated an alerting effect of short exposure to monochromatic blue light at midday and in the evening, which was demonstrated by a decrease in lower frequency bands (alpha1, delta, and theta, respectively). Long exposure to blue light may have a reverse effect, especially in the morning and at midday, when increases in lower frequency bands (theta in the morning and theta and alpha1 at midday) were observed. It can be concluded that the daytime effect of monochromatic blue light on EEG activity depends on timing and duration of exposure.

Cognitive Impairments in Occupational Burnout - Error Processing and Its Indices of Reactive and Proactive Control.

The presented study refers to cognitive aspects of burnout as the effects of long-term work-related stress. The purpose of the study was to investigate electrophysiological correlates of burnout to explain the mechanisms of the core burnout symptoms: exhaustion and depersonalization/cynicism. The analyzed error-related electrophysiological markers shed light on impaired cognitive mechanisms and the specific changes in information-processing in burnout. In the EEG study design (N = 80), two components of error-related potential (ERP), error-related negativity (ERN), and error positivity (Pe), were analyzed. In the non-clinical burnout group (N = 40), a significant increase in ERN amplitude and a decrease in Pe amplitude were observed compared to controls (N = 40). Enhanced error detection, indexed by increased ERN amplitude, and diminished response monitoring, indexed by decreased Pe amplitude, reveal emerging cognitive problems in the non-clinical burnout group. Cognitive impairments in burnout subjects relate to both reactive and unconscious (ERN) and proactive and conscious (Pe) aspects of error processing. The results indicate a stronger 'reactive control mode' that can deplete resources for proactive control and the ability to actively maintain goals. The analysis refers to error processing and specific task demands, thus should not be extended to cognitive processes in general. The characteristics of ERP patterns in burnout resemble psychophysiological indexes of anxiety (increased ERN) and depressive symptoms (decreased Pe), showing to some extent an overlapping effect of burnout and related symptoms and disorders. The results support the scarce existing data on the psychobiological nature of burnout, while extending and specifying its cognitive characteristics.

Neurophysiological Markers of Emotion Processing in Burnout Syndrome.

The substantial body of research employing subjective measures indicates that burnout syndrome is associated with cognitive and emotional dysfunctions. The growing amount of neurophysiological and neuroimaging research helps in broadening existing knowledge of the neural mechanisms underlying core burnout components (emotional exhaustion and depersonalization/cynicism) that are inextricably associated with emotional processing. In the presented EEG study, a group of 93 participants (55 women; mean age = 35.8) were selected for the burnout group or the demographically matched control group on the basis of the results of the Maslach Burnout Inventory - General Survey (MBI-GS) and the Areas of Worklife Survey (AWS). Subjects then participated in an EEG experiment using two experimental procedures: a facial recognition task and viewing of passive pictures. The study focuses on analyzing event-related potentials (ERPs): N170, VPP, EPN, and LPP, as indicators of emotional information processing. Our results show that burnout subjects, as compared to the control group, demonstrate significantly weaker response to affect-evoking stimuli, indexed by a decline in VPP amplitude to emotional faces and decreased EPN amplitude in processing emotional scenes. The analysis of N170 and LPP showed no significant between-group difference. The correlation analyses revealed that VPP and EPN, which are ERP components related to emotional processing, are associated with two core burnout symptoms: emotional exhaustion and cynicism. To our knowledge, we are one of the first research groups to use ERPs to demonstrate such a relationship between neurophysiological activity and burnout syndrome in the context of emotional processing. Thus, in conclusion we emphasized that the decreased amplitude of VPP and EPN components in the burnout group may be a neurophysiological manifestation of emotional blunting and may be considered as neurophysiological markers of emotional exhaustion and cynicism. Additionally, we did not observe a decrease in LPP, which may be considered as a marker that significantly differentiates burnout from depression.

Preliminary analyses of psychometric characteristics of the Polish version of the Obsessive-Compulsive Inventory-Revised (OCI-R) in a non-clinical sample.

OBJECTIVES: Obsessive-compulsive disorder (OCD) is an anxiety-spectrum disorder that affects 1-2% of the adult population. People with OCD are more likely to report impaired social and occupational functioning. Although effective treatments of the OCD exist, many sufferers from this disorder are continuously misdiagnosed. Therefore, improving the assessment of the OCD remains an important area of scientific research. The main goal of the study is the initial verification of psychometric properties in the Polish version of the Obsessive-Compulsive Inventory-Revised (OCI-R) in a college student sample. MATERIAL AND METHODS: A group of students completed a battery of measures consisting of obsessive-compulsive symptoms (The OCI-R, The Yale-Brown Obsessive Compulsive Scale), depression (The Beck Depression Inventory) and anxiety trait (The State-Trait Anxiety Inventory). RESULTS: A confirmatory factor analysis, conducted on data from 334 university students, supported a solid and replicable 6-fold factor structure of the OCI-R. Further analyses on test-retest reliability (following a 1-month interval), convergent and divergent validity of the OCI-R were respectively conducted in a group of 137 students who had completed a battery of measures mentioned above. The results showed adequate testretest reliability for the full scale and subscales cores, high internal consistency and confirmed satisfactory convergent and divergent validity. CONCLUSIONS: The study constitutes the first phase of work on a Polish version of measurement for obsessive-compulsive symptoms. Satisfactory results obtained in a non-clinical sample allow to recognize this method to be promising for further research. Int J Occup Med Environ Health 2016;29(6):1011-1021.

Job burnout and engagement among teachers - Worklife areas and personality traits as predictors of relationships with work.

INTRODUCTION: The main goal of the present study was to analyze the burnout syndrome due to selected personality traits (based on the Cloninger's psychobiological personality model and positive and negative affectivity) and the degree of mismatch between teachers and their work environment (described in terms of the Model of Worklife Areas). The 2nd goal was to determine if the participants could be classified into different burnout profile groups (clusters) based on their burnout dimension (exhaustion, cynicism and efficacy) scores and whether those groups differed significantly with regard to their personality traits and levels of mismatch between them and the workplace. MATERIAL AND METHODS: Individual and contextual factors responsible for burnout were analyzed in a group of 205 Polish teachers who completed a set of questionnaires: Maslach Burnout Inventory - General Scale, Areas of Worklife Scale, Temperament and Character Inventory, and Positive and Negative Affect Schedule. RESULTS: The hierarchical regression analysis revealed that teachers' efficacy is determined only by personality factors, while exhaustion and cynicism are determined by both individual and organizational variables. The cluster analysis revealed 3 groups (burnout, engaged, ineffective) that varied in the level of all burnout dimensions. Teachers experiencing burnout perceived a higher level of mismatch between themselves and the work environment, compared to the engaged teachers demonstrating better alignment. The engaged teachers were lower on negative affectivity and higher on self-directedness as compared to the burnout group. CONCLUSIONS: The study provided insight into the role of individual factors in the development of teacher burnout and engagement. Negative affectivity could be considered as a predisposing risk factor and self-directedness as a protective factor for burnout.

Diurnal patterns of activity of the orienting and executive attention neuronal networks in subjects performing a Stroop-like task: a functional magnetic resonance imaging study.

Attentional processes are fundamental to good cognitive functioning of human operators. The purpose of this study was to analyze the activity of neuronal networks involved in the orienting attention and executive control processes from the perspective of diurnal variability. Twenty-three healthy male volunteers meeting magnetic resonance (MR) inclusion criteria performed the Stroop Color-Word task (block design) in the MR scanner five times/day (06:00, 10:00, 14:00, 18:00, 22:00 h). The first scanning session was scheduled 1-1.5 h after waking. Between MR sessions, subjects performed simulated driving tasks in stable environmental conditions, with controlled physical activity and diet. Significant activation was found in brain regions related to the orienting attentional system: the parietal lobe (BA40) and frontal eye-fields (FEFs). There were also activations in areas of the executive control system: the fronto-insular cortex (FIC), dorsal anterior cingulate cortex (dACC), presupplementary motor area (preSMA), supplementary motor area (SMA), basal ganglia, middle temporal (MT; BA21), and dorsolateral prefrontal cortex (DLPFC), as a part of the central executive network. Significant deactivations were observed in the rostral anterior cingulate cortex (rACC), posterior cingulate cortex (PCC), superior frontal gyrus (SF), parietal lobe (BA39), and parahippocampal that are thought to comprise the default mode network (DMN). Additionally, the activated regions included bilaterally lingual gyrus and fusiform gyrus. The insula was bilaterally deactivated. Visual attention controlled by the goal-oriented attention system and comprising top-down and bottom-up mechanisms, activated by Stroop-like task, turned out to be prone to diurnal changes. The study results show the occurrence of time-of-day-related variations in neural activity of brain regions linked to the orienting attentional system (left parietal lobe-BA40, left and right FEFs), simultaneously providing arguments for temporal stability of the executive system and default mode network. These results also seem to suggest that the involuntary, exogenous (bottom-up) mechanism of attention is more vulnerable to circadian and fatigue factors than the voluntary (top-down) mechanism, which appear to be maintained at the same functional level during the day. The above phenomena were observed at the neural level.

Chronic sleep deficit and performance of a sustained attention task--an electrooculography study.

Electrooculography (EOG) was used to explore performance differences in a sustained attention task during rested wakefulness (RW) and after 7 days of partial sleep deprivation (SD). The RW condition was based on obtaining regular sleep, and the SD condition involved sleep restriction of 3 h/night for a week resulting in a total sleep debt of 21 h. The study used a counterbalanced design with a 2-wk gap between the conditions. Participants performed a sustained attention task for 45 min on four occasions: 10:00-11:00, 14:00-15:00, 18:00-19:00, and 22:00-23:00 h. The task required moving gaze and attention as fast as possible from a fixation point to a target. In each session, 120 congruent and 34 incongruent stimuli were presented, totaling 1232 observations/participant. Correct responses plus errors of omission (lapses) and commission (false responses) were recorded, and the effect of time-of-day on sustained attention following SD was investigated. The analysis of variance (ANOVA) model showed that SD affected performance on a sustained attention task and manifested itself in a higher number of omission errors: congruent stimuli (F((1,64)) = 13.3, p < .001) and incongruent stimuli (F((1,64)) = 14.0, p < .001). Reaction times for saccadic eye movements did not differ significantly between experimental conditions or by time-of-day. Commission errors, however, exhibited a decreasing trend during the day. The visible prevalence of omissions in SD versus RW was observed during the mid-afternoon hours (the so-called post-lunch dip) for both congruent and incongruent stimuli (F((1,16)) = 5.3, p = .04 and F((1,16)) = 5.6, p = .03, respectively), and at 18:00 h for incongruent stimuli (F((1,13)) = 5.7, p = .03).

Chronotype, sleep loss, and diurnal pattern of salivary cortisol in a simulated daylong driving.

The study focused on chronotype-related differences in subjective load assessment, sleepiness, and salivary cortisol pattern in subjects performing daylong simulated driving. Individual differences in work stress appraisal and psychobiological cost of prolonged load seem to be of importance in view of expanding compressed working time schedules. Twenty-one healthy, male volunteers (mean +/- SD: 27.9 +/- 4.9 yrs) were required to stay in semiconstant routine conditions. They performed four sessions (each lasting approximately 2.5 h) of simulated driving, i.e., completed chosen tasks from computer driving games. Saliva samples were collected after each driving session, i.e., at 10:00-11:00, 14:00-15:00, 18:00-19:00, and 22:00-23:00 h as well as 10-30 min after waking (between 05:00 and 06:00 h) and at bedtime (after 00:00 h). Two subgroups of subjects were distinguished on the basis of the Chronotype Questionnaire: morning (M)- and evening (E)-oriented types. Subjective data on sleep need, sleeping time preferences, sleeping problems, and the details of the preceding night were investigated by questionnaire. Subjective measures of task load (NASA Task Load Index [NASA-TLX]), activation (Thayer's Activation-Deactivation Adjective Check List [AD ACL]), and sleepiness (Karolinska Sleepiness Scale [KSS]) were applied at times of saliva samples collection. M- and E-oriented types differed significantly as to their ideal sleep length (6 h 54 min +/- 44 versus 8 h 13 min +/- 50 min), preferred sleep timing (midpoint at 03:19 versus 04:26), and sleep index, i.e., 'real-to-ideal' sleep ratio, before the experimental day (0.88 versus 0.67). Sleep deficit proved to be integrated with eveningness. M and E types exhibited similar diurnal profiles of energy, tiredness, tension, and calmness assessed by AD ACL, but E types estimated higher their workload (NASA-TLX) and sleepiness (KSS). M types exhibited a trend of higher mean cortisol levels than E types (F = 4.192, p < .056) and distinct diurnal variation (F = 2.950, p < .019), whereas E types showed a flattened diurnal curve. Cortisol values did not correlate with subjective assessments of workload, arousal, or sleepiness at any time-of-day. Diurnal cortisol pattern parameters (i.e., morning level, mean level, and range of diurnal changes) showed significant positive correlations with sleep length before the experiment (r = .48, .54, and .53, respectively) and with sleep index (r = .63, .64, and .56, respectively). The conclusions of this study are: (i) E-oriented types showed lower salivary cortisol levels and a flattened diurnal curve in comparison with M types; (ii) sleep loss was associated with lower morning cortisol and mean diurnal level, whereas higher cortisol levels were observed in rested individuals. In the context of stress theory, it may be hypothesized that rested subjects perceived the driving task as a challenge, whereas those with reduced sleep were not challenged, but bored/exhausted with the experimental situation.