Stress and Sleep Disorders Study Notes

Stress and Sleep Disorders

Overview

  • Key Topics

    • What is Sleep?

    • The Basics of Sleep Disorders

    • The HPA Axis and Sleep

    • Stress and Sleep

    • Treatment

    • Stress and Dreams

    • Sleep Hygiene

Sleep

  • Stages of Sleep

    • Sleep cycles through four stages:

    • NREM (Non-Rapid Eye Movement)

      • Stage 1:

      • Duration: About 10 minutes

      • Percentage of Total Sleep Time: 5%

      • Characteristics: Very easy to wake, brain activity transitions from Alpha to Theta waves.

      • Stage 2:

      • Duration: 30 to 60 minutes

      • Percentage of Total Sleep Time: 50%

      • Characteristics: Harder to wake, may start seeing Delta waves.

      • Stage 3:

      • Duration: 20 to 30 minutes in the first cycle, decreasing in subsequent cycles

      • Percentage of Total Sleep Time: 20%

      • Characteristics: Deep sleep, hardest stage to wake from.

    • REM Sleep (Rapid Eye Movement):

      • Characteristics: Heart rate, breathing, and blood pressure fluctuate; muscle twitching occurs; dreaming happens; body is paralyzed to prevent acting out dreams.

      • Duration: May last a few minutes in the first cycle, increasing to up to an hour in later cycles.

      • Percentage of Total Sleep Time: 25%.

  • Sleep Cycles: Approximately six cycles each lasting around 90 minutes.

Circadian Rhythm

  • Definition of Circadian Rhythm: A biological clock that regulates various bodily functions, including sleep/wake cycles and the duration of sleep.

Sleep Theories

  • Restoration Theory: Zager et al. (2007) proposed that proper immune function is dependent on sleep.

  • Ontogenesis Theory:

    • Morrisey et al. (2004): REM sleep contributes to brain development by preventing apoptosis in the developing brain.

    • Marks et al. (1995): REM sleep promotes brain maturation through increased neural activity.

  • Learning and Memory Theory: Sleep deprivation negatively impacts memory, particularly working memory.

Sleep Disorders

  • Categories of Sleep Disorders:

    • Dyssomnias: Disorders leading to difficulty in initiating or maintaining sleep or excessive sleepiness.

    • Subcategories:

      • Intrinsic Sleep Disorders

      • Extrinsic Sleep Disorders

      • Circadian Rhythm Sleep Disorders

    • Parasomnias: Disorders that intrude into the sleep process; they are manifestations of CNS activation.

    • Subgroups:

      • Arousal Disorders

      • Sleep-Wake Transition Disorders

      • Parasomnias Associated with REM Sleep

      • Other Parasomnias

    • Sleep Disorders Associated with Mental, Neurologic, or Other Medical Disorders

Dyssomnias: Insomnia

  • Types:

    • Mild Insomnia: Characterized by insufficient sleep without feeling rested, minimal or no social/occupational impairment.

    • Moderate Insomnia: Almost nightly occurrences with mild to moderate impairment, irritability, and daytime fatigue.

    • Severe Insomnia: Nightly occurrences with severe impairment and fatigue.

  • Psychophysiologic Insomnia: Develops from somatized tension and learned associations that prevent sleep, resulting in a preoccupation with sleep difficulties.

Hypersomnia

  • Description: Extreme somnolence lasting 18 to 20 hours a day, potentially persisting for days to weeks; more prevalent in males.

Bruxism

  • Definition: Grinding and clenching teeth during sleep, leading to tooth wear, jaw pain, and headaches. Affects 5% of the population.

Sleep Enuresis

  • Definition: Also known as bed-wetting; must persist after the age of 5. Very rare in adults.

The Bidirectional Relationship of Stress & Sleep

  • HPA Axis Impact: Regulation of the HPA axis and changes in sleep are interdependent. Daytime stress can diminish sleep quality, which may exacerbate daytime stress, creating a downward spiral towards increased allostatic load and illness.

HPA Axis & Sleep

  • Studies:

    • Increased corticosterone and ACTH levels are observed post sleep deprivation.

    • Capaldi et al. (2005) found sleep issues correlate with damaging cortisol responses to stress.

Effects of Stress on Sleep

  • Stressful daytime events adversely affect sleep patterns, independent of depression, influencing people's sleep physiology.

  • Research by Lauer & Lund (1987) demonstrated the impact of pre-sleep emotional states on REM phases.

Stress in the Workplace and Relationships

  • Job Stress: Lange et al. (2009) identified work strain as a determinant for sleep quality.

  • Marital Stress: Rauer et al. (2010) found psychological abuse within relationships predicts later sleep issues, emphasizing the role of safety and security for quality sleep.

Sleep Disorders Associated with Stress

  • Hypersomnia: Often co-occurs with depression, as highlighted by Kaplan (1994).

  • Bruxism: Increased negative coping strategies correlate with bruxism, as observed in surveys examining daily stress variables.

  • Nocturnal Enuresis: Trombini et al. (1982) associated stress with bladder contractions but concluded it does not contribute to primary nocturnal enuresis.

Personality Traits and Their Impact on Sleep Problems

  • Neuroticism's Role: High neuroticism correlates with poorer stress coping mechanisms, poor sleep, and increased sensitivity to sleep disruptions.

    • Study by William & Moroz (2009) linked neuroticism and conscientiousness with sleep quality issues.

Rumination and Sleep Quality

  • Definition of Rumination: Continuous contemplation of past problems, similar to worry, known to negatively impact sleep quality.

  • Study Findings: Guastella & Moulds (2006) revealed that high-trait ruminators reported more disturbances in sleep when engaging in rumination.

Stress and Dreams

  • Dreams Mechanism: Dreams occur during both NREM and REM sleep, with REM dreams being more emotionally charged.

  • Negative Dream Content: Increases with stress levels, as shown by studies like Berger et al. (1971).

  • Continuity Hypothesis of Dreaming: Suggests that we process daily experiences through our dreams.

Nightmares and Their Implications

  • Nightmares may sometimes serve as coping mechanisms but can disrupt sleep when pathological.

  • Research by Picchioni et al. (2002) established a link between nightmares and coping capacities.

Treatment for Sleep Disorders

  • Challenges with Medication: Effects of hypnotics tend to diminish over time.

  • Cognitive Behavioral Therapy for Insomnia (CBT-I): Includes various techniques such as:

    • Sleep reduction therapy

    • Stimulus control therapy

    • Cognitive therapy

    • Sleep hygiene education

  • Mindfulness-Based Stress Reduction (MBSR): Encourages awareness of current feelings and practices non-judgmental acknowledgment of experiences. Buddha's teachings outline benefits associated with mindfulness for sleep quality.

Sleep Hygiene

  • Guidelines for Better Sleep:

    • Avoid bedtime unless sleepy.

    • Establish a pre-sleep routine.

    • Wake up consistently at the same time, even on weekends.

    • Refrain from napping.

    • Aim for a full night’s sleep.

    • Limit activities like eating or watching TV in bed.

    • Create a dark, quiet, and cool sleeping environment.

Signs of Sleep Deprivation

  • Dependence on alarm clocks.

  • High caffeine intake in the morning.

  • Increased frequency of illness.

  • Memory lapses, mistakes, and irritability.