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Research paper thumbnail of Sustaining executive functions during sleep deprivation: A comparison of caffeine, dextroamphetamine, and modafinil

Sleep

Stimulant medications appear effective at restoring simple alertness and psychomotor vigilance in... more Stimulant medications appear effective at restoring simple alertness and psychomotor vigilance in sleep deprived individuals, but it is not clear whether these medications are effective at restoring higher order complex cognitive capacities such as planning, sequencing, and decision making. After 44 hours awake, participants received a double-blind dose of one of 3 stimulant medications or placebo. After 45-50 hours awake, participants were tested on computerized versions of the 5-Ring Tower of Hanoi (TOH), the Tower of London (TOL), and the Wisconsin Card Sorting Test (WCST). In-residence sleep-laboratory facility at the Walter Reed Army Institute of Research. Fifty-four healthy adults (29 men, 25 women), ranging in age from 18 to 36 years. Interventions: Participants were randomly assigned to 1 of 3 stimulant medication groups, including caffeine, 600 mg (n=12), modafinil, 400 mg (n=12), dextroamphetamine, 20 mg (n=16), or placebo (n=14). At the doses tested, modafinil and dextroa...

Research paper thumbnail of Sustaining executive functions during sleep deprivation: A comparison of caffeine, dextroamphetamine, and modafinil

Sleep, 2009

Stimulant medications appear effective at restoring simple alertness and psychomotor vigilance in... more Stimulant medications appear effective at restoring simple alertness and psychomotor vigilance in sleep deprived individuals, but it is not clear whether these medications are effective at restoring higher order complex cognitive capacities such as planning, sequencing, and decision making. After 44 hours awake, participants received a double-blind dose of one of 3 stimulant medications or placebo. After 45-50 hours awake, participants were tested on computerized versions of the 5-Ring Tower of Hanoi (TOH), the Tower of London (TOL), and the Wisconsin Card Sorting Test (WCST). In-residence sleep-laboratory facility at the Walter Reed Army Institute of Research. Fifty-four healthy adults (29 men, 25 women), ranging in age from 18 to 36 years. Participants were randomly assigned to 1 of 3 stimulant medication groups, including caffeine, 600 mg (n=12), modafinil, 400 mg (n=12), dextroamphetamine, 20 mg (n=16), or placebo (n=14). At the doses tested, modafinil and dextroamphetamine grou...

Research paper thumbnail of Sleep deprivation reduces perceived emotional intelligence and constructive thinking skills

Sleep Medicine, 2008

Background and purpose: Insufficient sleep can adversely affect a variety of cognitive abilities,... more Background and purpose: Insufficient sleep can adversely affect a variety of cognitive abilities, ranging from simple alertness to higher-order executive functions. Although the effects of sleep loss on mood and cognition are well documented, there have been no controlled studies examining its effects on perceived emotional intelligence (EQ) and constructive thinking, abilities that require the integration of affect and cognition and are central to adaptive functioning. Patients and methods: Twenty-six healthy volunteers completed the Bar-On Emotional Quotient Inventory (EQi) and the Constructive Thinking Inventory (CTI) at rested baseline and again after 55.5 and 58 h of continuous wakefulness, respectively. Results: Relative to baseline, sleep deprivation was associated with lower scores on Total EQ (decreased global emotional intelligence), Intrapersonal functioning (reduced self-regard, assertiveness, sense of independence, and self-actualization), Interpersonal functioning (reduced empathy toward others and quality of interpersonal relationships), Stress Management skills (reduced impulse control and difficulty with delay of gratification), and Behavioral Coping (reduced positive thinking and action orientation). Esoteric Thinking (greater reliance on formal superstitions and magical thinking processes) was increased. Conclusions: These findings are consistent with the neurobehavioral model suggesting that sleep loss produces temporary changes in cerebral metabolism, cognition, emotion, and behavior consistent with mild prefrontal lobe dysfunction. Published by Elsevier B.V.

Research paper thumbnail of The effects of sleep deprivation on symptoms of psychopathology in healthy adults

Sleep Medicine, 2007

Background: Sleep loss leads to temporary changes in mood and cognition, and is associated with r... more Background: Sleep loss leads to temporary changes in mood and cognition, and is associated with reduced cerebral metabolism within the prefrontal cortex, similar to findings observed in some psychiatric disorders. However, the extent to which sleep deprivation may be associated with the emergence of clinical symptoms of psychopathology in healthy normal individuals is not clear. Methods: The Personality Assessment Inventory (PAI) was administered to 25 healthy adults at rested baseline and again after 56 h of continuous wakefulness. Results: Comparisons showed a significant global increase in PAI psychopathology scores from baseline to sleep-deprived sessions, particularly for somatic complaints, anxiety, depression, and paranoia. Mean elevations for the clinical scales remained within normal limits, however. In contrast, sleep loss was not associated with significant changes in anxiety-related disorders, manic symptoms, borderline, schizophrenic, or antisocial features. Conclusions: Two nights without sleep may lead to a sub-clinical increase in self-reported affective symptoms of psychopathology while having little effect on symptoms of thought disorder, psychotic processes, or behavioral dysregulation. These data suggest that sleep loss may be differentially disruptive to regions of the brain involved in affective regulation and may, therefore, serve as a model for understanding the brain dysfunction associated with affective psychopathology. Published by Elsevier B.V.

Research paper thumbnail of Sleep deprivation adversely affects interpersonal responses to frustration

Personality and Individual Differences, 2006

Sleep deprivation produces negative effects on mood and cognitive function, but existing data hav... more Sleep deprivation produces negative effects on mood and cognitive function, but existing data have almost exclusively utilized objective rating scales, which do not permit evaluation of idiosyncratic and unstructured responses. In this study, we used a semi-projective measure, the Rosenzweig Picture-Frustration (P-F) Study, to assess subjective responses to frustration following two nights without sleep. Twentysix healthy volunteers completed the P-F at rested baseline and again following 55 h of continuous wakefulness. Participants provided written responses for an ambiguous cartoon character confronted with various frustrating situations. Relative to rested baseline, sleep deprivation was associated with altered responses on several indices, indicating a great number of uncommon types of responses, increased tendency to blame others for problems, and a reduced willingness to alleviate a conflict situation by accepting blame. Individual differences in several aspects of emotional intelligence were predictive of the extent to which responses to frustration changed with sleep loss. These findings suggest that sleep deprivation significantly weakens the inhibition of aggression and willingness to behave in ways that facilitate effective social interaction, possibly through reduced metabolic activity in prefrontal regions of the brain important for personality, affect, and inhibitory behavior.

Research paper thumbnail of Effects of Acute Caffeine Withdrawal on Short Category Test Performance in Sleep-Deprived Individuals 1,2

Perceptual and Motor Skills, 2007

Summay.-Caffeine is a popular stimulant often used to counter the effects of sleep loss and fatig... more Summay.-Caffeine is a popular stimulant often used to counter the effects of sleep loss and fatigue. Withdrawal from caffeine may produce mild declines in simple cognitive capacities such as attention and concentration, but it is unclear whether more complex cognitive functions, such as abstract reasoning or concept formation, may be similarly affected. To assess the effect of acute caffeine withdrawal on executive functioning during sleep deprivation, 26 healthy volunteers were administered in double-blind form either repeated doses of caffcine or placebo over two nights of continuous wakefulness. The 108-item Short Category Test was administered after 56 hr. of total sleep deprivation (9 hr. post-caffeine administration). The caffeine group scored significantly more poorly, making approximately 57% more errors on the test than the placebo group. These findings suggest that acute caffeine withdrawal during prolonged sleep deprivation has an adverse effect on abstract reasoning and concept formation.

Research paper thumbnail of Clinical Improvements of Suicidal Outpatients: Examining Suicide Status Form Responses as Predictors and Moderators

Archives of Suicide Research, 2009

This investigation used hierarchical linear modeling (HLM) to examine whether index responses on ... more This investigation used hierarchical linear modeling (HLM) to examine whether index responses on the Suicide Status Form (SSF) moderated the predicted sessionto-session change over course of care in overall symptoms and suicidal ideation. Ninety-two suicidal patients at a university counseling center were studied. Overall, suicidal patients improved symptomatically and decreased their suicidal ideation over the course of care. SSF index ratings of overall risk of suicide significantly moderated the predicted session-to-session change in suicidal ideation over the course of care; patient ratings of frequency of suicidal thoughts were also moderated by index SSF ratings of hopelessness and self-hate. These findings partially replicated earlier data of differential treatment response outcomes and provide valuable assessment and treatment information that is relevant to future research and successful clinical care of suicidal outpatients.

Research paper thumbnail of Sustaining executive functions during sleep deprivation: A comparison of caffeine, dextroamphetamine, and modafinil

Sleep

Stimulant medications appear effective at restoring simple alertness and psychomotor vigilance in... more Stimulant medications appear effective at restoring simple alertness and psychomotor vigilance in sleep deprived individuals, but it is not clear whether these medications are effective at restoring higher order complex cognitive capacities such as planning, sequencing, and decision making. After 44 hours awake, participants received a double-blind dose of one of 3 stimulant medications or placebo. After 45-50 hours awake, participants were tested on computerized versions of the 5-Ring Tower of Hanoi (TOH), the Tower of London (TOL), and the Wisconsin Card Sorting Test (WCST). In-residence sleep-laboratory facility at the Walter Reed Army Institute of Research. Fifty-four healthy adults (29 men, 25 women), ranging in age from 18 to 36 years. Interventions: Participants were randomly assigned to 1 of 3 stimulant medication groups, including caffeine, 600 mg (n=12), modafinil, 400 mg (n=12), dextroamphetamine, 20 mg (n=16), or placebo (n=14). At the doses tested, modafinil and dextroa...

Research paper thumbnail of Sustaining executive functions during sleep deprivation: A comparison of caffeine, dextroamphetamine, and modafinil

Sleep, 2009

Stimulant medications appear effective at restoring simple alertness and psychomotor vigilance in... more Stimulant medications appear effective at restoring simple alertness and psychomotor vigilance in sleep deprived individuals, but it is not clear whether these medications are effective at restoring higher order complex cognitive capacities such as planning, sequencing, and decision making. After 44 hours awake, participants received a double-blind dose of one of 3 stimulant medications or placebo. After 45-50 hours awake, participants were tested on computerized versions of the 5-Ring Tower of Hanoi (TOH), the Tower of London (TOL), and the Wisconsin Card Sorting Test (WCST). In-residence sleep-laboratory facility at the Walter Reed Army Institute of Research. Fifty-four healthy adults (29 men, 25 women), ranging in age from 18 to 36 years. Participants were randomly assigned to 1 of 3 stimulant medication groups, including caffeine, 600 mg (n=12), modafinil, 400 mg (n=12), dextroamphetamine, 20 mg (n=16), or placebo (n=14). At the doses tested, modafinil and dextroamphetamine grou...

Research paper thumbnail of Sleep deprivation reduces perceived emotional intelligence and constructive thinking skills

Sleep Medicine, 2008

Background and purpose: Insufficient sleep can adversely affect a variety of cognitive abilities,... more Background and purpose: Insufficient sleep can adversely affect a variety of cognitive abilities, ranging from simple alertness to higher-order executive functions. Although the effects of sleep loss on mood and cognition are well documented, there have been no controlled studies examining its effects on perceived emotional intelligence (EQ) and constructive thinking, abilities that require the integration of affect and cognition and are central to adaptive functioning. Patients and methods: Twenty-six healthy volunteers completed the Bar-On Emotional Quotient Inventory (EQi) and the Constructive Thinking Inventory (CTI) at rested baseline and again after 55.5 and 58 h of continuous wakefulness, respectively. Results: Relative to baseline, sleep deprivation was associated with lower scores on Total EQ (decreased global emotional intelligence), Intrapersonal functioning (reduced self-regard, assertiveness, sense of independence, and self-actualization), Interpersonal functioning (reduced empathy toward others and quality of interpersonal relationships), Stress Management skills (reduced impulse control and difficulty with delay of gratification), and Behavioral Coping (reduced positive thinking and action orientation). Esoteric Thinking (greater reliance on formal superstitions and magical thinking processes) was increased. Conclusions: These findings are consistent with the neurobehavioral model suggesting that sleep loss produces temporary changes in cerebral metabolism, cognition, emotion, and behavior consistent with mild prefrontal lobe dysfunction. Published by Elsevier B.V.

Research paper thumbnail of The effects of sleep deprivation on symptoms of psychopathology in healthy adults

Sleep Medicine, 2007

Background: Sleep loss leads to temporary changes in mood and cognition, and is associated with r... more Background: Sleep loss leads to temporary changes in mood and cognition, and is associated with reduced cerebral metabolism within the prefrontal cortex, similar to findings observed in some psychiatric disorders. However, the extent to which sleep deprivation may be associated with the emergence of clinical symptoms of psychopathology in healthy normal individuals is not clear. Methods: The Personality Assessment Inventory (PAI) was administered to 25 healthy adults at rested baseline and again after 56 h of continuous wakefulness. Results: Comparisons showed a significant global increase in PAI psychopathology scores from baseline to sleep-deprived sessions, particularly for somatic complaints, anxiety, depression, and paranoia. Mean elevations for the clinical scales remained within normal limits, however. In contrast, sleep loss was not associated with significant changes in anxiety-related disorders, manic symptoms, borderline, schizophrenic, or antisocial features. Conclusions: Two nights without sleep may lead to a sub-clinical increase in self-reported affective symptoms of psychopathology while having little effect on symptoms of thought disorder, psychotic processes, or behavioral dysregulation. These data suggest that sleep loss may be differentially disruptive to regions of the brain involved in affective regulation and may, therefore, serve as a model for understanding the brain dysfunction associated with affective psychopathology. Published by Elsevier B.V.

Research paper thumbnail of Sleep deprivation adversely affects interpersonal responses to frustration

Personality and Individual Differences, 2006

Sleep deprivation produces negative effects on mood and cognitive function, but existing data hav... more Sleep deprivation produces negative effects on mood and cognitive function, but existing data have almost exclusively utilized objective rating scales, which do not permit evaluation of idiosyncratic and unstructured responses. In this study, we used a semi-projective measure, the Rosenzweig Picture-Frustration (P-F) Study, to assess subjective responses to frustration following two nights without sleep. Twentysix healthy volunteers completed the P-F at rested baseline and again following 55 h of continuous wakefulness. Participants provided written responses for an ambiguous cartoon character confronted with various frustrating situations. Relative to rested baseline, sleep deprivation was associated with altered responses on several indices, indicating a great number of uncommon types of responses, increased tendency to blame others for problems, and a reduced willingness to alleviate a conflict situation by accepting blame. Individual differences in several aspects of emotional intelligence were predictive of the extent to which responses to frustration changed with sleep loss. These findings suggest that sleep deprivation significantly weakens the inhibition of aggression and willingness to behave in ways that facilitate effective social interaction, possibly through reduced metabolic activity in prefrontal regions of the brain important for personality, affect, and inhibitory behavior.

Research paper thumbnail of Effects of Acute Caffeine Withdrawal on Short Category Test Performance in Sleep-Deprived Individuals 1,2

Perceptual and Motor Skills, 2007

Summay.-Caffeine is a popular stimulant often used to counter the effects of sleep loss and fatig... more Summay.-Caffeine is a popular stimulant often used to counter the effects of sleep loss and fatigue. Withdrawal from caffeine may produce mild declines in simple cognitive capacities such as attention and concentration, but it is unclear whether more complex cognitive functions, such as abstract reasoning or concept formation, may be similarly affected. To assess the effect of acute caffeine withdrawal on executive functioning during sleep deprivation, 26 healthy volunteers were administered in double-blind form either repeated doses of caffcine or placebo over two nights of continuous wakefulness. The 108-item Short Category Test was administered after 56 hr. of total sleep deprivation (9 hr. post-caffeine administration). The caffeine group scored significantly more poorly, making approximately 57% more errors on the test than the placebo group. These findings suggest that acute caffeine withdrawal during prolonged sleep deprivation has an adverse effect on abstract reasoning and concept formation.

Research paper thumbnail of Clinical Improvements of Suicidal Outpatients: Examining Suicide Status Form Responses as Predictors and Moderators

Archives of Suicide Research, 2009

This investigation used hierarchical linear modeling (HLM) to examine whether index responses on ... more This investigation used hierarchical linear modeling (HLM) to examine whether index responses on the Suicide Status Form (SSF) moderated the predicted sessionto-session change over course of care in overall symptoms and suicidal ideation. Ninety-two suicidal patients at a university counseling center were studied. Overall, suicidal patients improved symptomatically and decreased their suicidal ideation over the course of care. SSF index ratings of overall risk of suicide significantly moderated the predicted session-to-session change in suicidal ideation over the course of care; patient ratings of frequency of suicidal thoughts were also moderated by index SSF ratings of hopelessness and self-hate. These findings partially replicated earlier data of differential treatment response outcomes and provide valuable assessment and treatment information that is relevant to future research and successful clinical care of suicidal outpatients.