Emotions play a key role in overall mental health, [1] and sleep plays a crucial role in maintaining the optimal homeostasis of emotional functioning. [2] [3] Deficient sleep, both in the form of sleep deprivation and restriction, adversely impacts emotion generation, emotion regulation, and emotional expression. [4]
Scientists offer two explanations for the effects of sleep loss on emotions. One explanation is that sleep loss causes disinhibition of emotional brain regions, leading to an overall increase in emotional intensity [5] (also referred to as Dysregulation Model). The other explanation describes how sleep loss causes an increase in fatigue and sleepiness, coupled with an overall decrease in energy and arousal, leading to an overall decrease in emotional intensity [6] (also referred to as Fatigue Model).
The dysregulation model is supported by neuroanatomical, physiological, and subjective self-report studies. Emotional brain regions (e.g. the amygdala) have shown 60% greater reactivity to emotionally negative photographs following one night of sleep deprivation, as measured by functional magnetic resonance imaging. [5] Five days of sleep restriction (four hour sleep opportunity per night) caused a decrease in connectivity with cortical brain regions involved in the regulation of the amygdala. [7] Pupil diameter was shown to increase significantly in response to negative photographs following sleep deprivation. [8] When exposed to positive stimuli, sleep deprived participants showed amplified emotional reactivity throughout various midbrain, striatal, limbic, and visual processing brain regions. [9] One night of sleep deprivation caused participants to judge neutral images more negatively than non sleep deprived participants. [10] One night of sleep loss also caused increased impulsivity to negative stimuli. [11]
The fatigue-model is supported by subjective self-report and physiological studies. Arousal, as measured by electroencephalograph (EEG), decreases as sleep loss increases, [6] leading to a decrease in the desire to perform and exert effort. Short-term sleep loss is associated with blunting in the recognition of negative and positive facial expressions. [12] Various forms of emotional expression, including facial and vocal expression, are adversely affected by sleep loss. Following one night of sleep deprivation, participants show decreased facial expressiveness in response to positive stimuli, [13] as well as decreased vocal expression of positive emotion. [14] Sleep deprivation slows the generation of facial reactions in response to emotional faces. [15] One to two nights of sleep loss in healthy adults is associated with a decrease in the generated intensity of positive moods (i.e. happiness and activation), as well as an increase in the generated intensity of negative moods (i.e. anger, depression, fear, and fatigue). Long-term chronic exposure to insufficient sleep is associated with a decline in optimism and sociability, and an increase in subjective experiences of sleepiness and fatigue. [16] Furthermore, sleep restricted to five hours a night over the course of a week causes significant increases in self-reports of subjective mood disturbance and sleepiness. [17]
Deficient sleep patterns are prominent in many psychiatric ailments. [18] Insomnia increases the risk of a depressive episode, sleep deprivation influences the onset of hypomania, and sleep disturbance contributes to the maintenance of mood disorders. [19] Amongst manic bipolar patients, sleep loss may act as a trigger in the onset of a manic episode. [20]
Sleep patterns are affected by behavioral and emotional disorders, and aspects of emotional and cognitive well-being are influenced by sleep patterns. [21] Scientists have examined the effects of deficient sleep patterns on emotion regulation in individuals diagnosed with mental disorders ( e.g. depression and anxiety), [22] borderline personality disorder, bipolar disorder, [19] and panic disorder. [23] Methods typically include observational, subjective, behavioral, and physiological measures of emotional functioning. [24]
Emotion regulation difficulties are associated with greater symptoms of depression, anxiety, [25] and borderline personality, that worsen with poor sleep patterns. Heart rate variability (HRV) is described as the time interval between heartbeats, and is linked to emotion regulation capacity, [26] with higher resting HRV is associated with greater emotion regulation capacity, and lower resting HRV is associated with low emotion regulation capacity. [27] Physiological data suggests that HRV is negatively affected by sleep loss, [24] as seen in panic disorder patients with poor sleep quality who display increased cognitive inhibition due to reduced HRV. [23] Emotion dysregulation has also been shown to play a role in the maintenance of generalized anxiety disorder, [28] panic disorder, [29] obsessive-compulsive disorder, [30] and posttraumatic stress disorder. [31] Overall deficient sleep plays a role in dampening emotions in clinical populations already susceptible to emotion dysregulation, as well as maintaining various psychiatric conditions through contributing to emotion dysfunction. [32]
Several important emotional characteristics that develop in childhood have been linked to sleep quality and duration, for example approachability, adaptability and attachment. [33] Sleep disruption has been argued to play a role in crying frequency. Crying was interpreted as an early form of a behavioral dysregulation and has therefore been linked to emotion regulation. [34]
It is hypothesized that dreaming might be a way of improving mood in non-clinical populations. [35] The evidence for this phenomenon has been collected from home dream reports in psychotherapy and from laboratory dreams collected after waking a participant in a REM sleep phase. [36] Adults often remember dreams which have a negative emotional component, whereby women recall more dreams than men and dream recall is associated with a higher level of anxiety and lighter sleep. [37]
In a study [38] conducted with depressed and healthy adults and were able to show that in healthy subjects, dreaming was a way to positively influence mood and cope with stress at night. Dreams of depressed persons, however, might deteriorate their mood further. This study's interesting results are limited in generalizability due to the small sample and the lack of reported dreams by depressed patients.
Emotions are more apparent in stages of REM-sleep rather than other stages of sleep. [39] It was found that during REM-sleep negative emotions diminish. [39] After going through stages of REM-sleep, people with depression report feeling better, in a study done by Cartwright et al. [40] Conversely, a theory proposed by Revonsuo [41] states that when people experience negative emotions or negative events, when they sleep the REM-sleep replays such events, which is known as rehearsal. [39] During REM-sleep areas of the brain, the suborbital area, and the cortical area are responsible for emotion but also a suppression of arousing emotions are activated. [39] Scientists noticed a decrease in the hormone noradrenaline which is released into the body after a highly stimulating event. [39] People reported trouble falling asleep or sleeping consistently throughout the night when a stressful event was happening in their life, as observed by Åkerstedt. [42] REM-sleep aids people with negative emotion or high stress. [39]
The circadian rhythm provides a person with a signal for when to sleep and when to wake up. [43] If circadian rhythm and sleep-wake cycle are misaligned, this might lead to negative affect and emotional instability. [44] It has been found that emotions vary depending on the circadian rhythm and the duration of how long one was awake. [45] Circadian sleep-rhythm disorders like shift-work disorder or Jetlag-disorder have been found to similarly contribute to the Dysregulation of affect, with symptoms like irritability, anxiety, apathy and dysphoria. [46]
Sleep is a state of reduced mental and physical activity in which consciousness is altered and certain sensory activity is inhibited. During sleep, there is a marked decrease in muscle activity and interactions with the surrounding environment. While sleep differs from wakefulness in terms of the ability to react to stimuli, it still involves active brain patterns, making it more reactive than a coma or disorders of consciousness.
A sleep disorder, or somnipathy, is a medical disorder affecting an individual's sleep patterns, sometimes impacting physical, mental, social, and emotional functioning. Polysomnography and actigraphy are tests commonly ordered for diagnosing sleep disorders.
Rapid eye movement sleep is a unique phase of sleep in mammals and birds, characterized by random rapid movement of the eyes, accompanied by low muscle tone throughout the body, and the propensity of the sleeper to dream vividly. The core body and brain temperatures increase during REM sleep and skin temperature decreases to lowest values.
In psychology, a mood is an affective state. In contrast to emotions or feelings, moods are less specific, less intense and less likely to be provoked or instantiated by a particular stimulus or event. Moods are typically described as having either a positive or negative valence. In other words, people usually talk about being in a good mood or a bad mood. There are many different factors that influence mood, and these can lead to positive or negative effects on mood.
Depersonalization is a dissociative phenomenon characterized by a subjective feeling of detachment from oneself, manifesting as a sense of disconnection from one's thoughts, emotions, sensations, or actions, and often accompanied by a feeling of observing oneself from an external perspective. Subjects perceive that the world has become vague, dreamlike, surreal, or strange, leading to a diminished sense of individuality or identity. Sufferers often feel as though they are observing the world from a distance, as if separated by a barrier "behind glass". They maintain insight into the subjective nature of their experience, recognizing that it pertains to their own perception rather than altering objective reality. This distinction between subjective experience and objective reality distinguishes depersonalization from delusions, where individuals firmly believe in false perceptions as genuine truths. Depersonalization is also distinct from derealization, which involves a sense of detachment from the external world rather than from oneself.
A mood swing is an extreme or sudden change of mood. Such changes can play a positive or a disruptive part in promoting problem solving and in producing flexible forward planning. When mood swings are severe, they may be categorized as part of a mental illness, such as bipolar disorder, where erratic and disruptive mood swings are a defining feature.
Sleep debt or sleep deficit is the cumulative effect of not getting enough sleep. A large sleep debt may lead to mental or physical fatigue, and can adversely affect one's mood, energy, and ability to think clearly.
Wake therapy is a specific application of intentional sleep deprivation. It encompasses many sleep-restricting paradigms that aim to address mood disorders with a form of non-pharmacological therapy.
Affective neuroscience is the study of how the brain processes emotions. This field combines neuroscience with the psychological study of personality, emotion, and mood. The basis of emotions and what emotions are remains an issue of debate within the field of affective neuroscience.
Reduced affect display, sometimes referred to as emotional blunting or emotional numbing, is a condition of reduced emotional reactivity in an individual. It manifests as a failure to express feelings either verbally or nonverbally, especially when talking about issues that would normally be expected to engage emotions. In this condition, expressive gestures are rare and there is little animation in facial expression or vocal inflection. Additionally, reduced affect can be symptomatic of autism, schizophrenia, depression, post-traumatic stress disorder, depersonalization-derealization disorder, schizoid personality disorder or brain damage. It may also be a side effect of certain medications.
Emotional dysregulation is characterized by an inability to flexibly respond to and manage emotional states, resulting in intense and prolonged emotional reactions that deviate from social norms, given the nature of the environmental stimuli encountered. Such reactions not only deviate from accepted social norms but also surpass what is informally deemed appropriate or proportional to the encountered stimuli.
The self-regulation of emotion or emotion regulation is the ability to respond to the ongoing demands of experience with the range of emotions in a manner that is socially tolerable and sufficiently flexible to permit spontaneous reactions as well as the ability to delay spontaneous reactions as needed. It can also be defined as extrinsic and intrinsic processes responsible for monitoring, evaluating, and modifying emotional reactions. The self-regulation of emotion belongs to the broader set of emotion regulation processes, which includes both the regulation of one's own feelings and the regulation of other people's feelings.
Sleep deprivation, also known as sleep insufficiency or sleeplessness, is the condition of not having adequate duration and/or quality of sleep to support decent alertness, performance, and health. It can be either chronic or acute and may vary widely in severity. All known animals sleep or exhibit some form of sleep behavior, and the importance of sleep is self-evident for humans, as nearly a third of a person's life is spent sleeping. Sleep deprivation is common as it affects about one-third of the population.
Emotional responsivity is the ability to acknowledge an affective stimuli by exhibiting emotion. It is a sharp change of emotion according to a person's emotional state. Increased emotional responsivity refers to demonstrating more response to a stimulus. Reduced emotional responsivity refers to demonstrating less response to a stimulus. Any response exhibited after exposure to the stimulus, whether it is appropriate or not, would be considered as an emotional response. Although emotional responsivity applies to nonclinical populations, it is more typically associated with individuals with schizophrenia and autism.
The biology of depression is the attempt to identify a biochemical origin of depression, as opposed to theories that emphasize psychological or situational causes.
Disruptive mood dysregulation disorder (DMDD) is a mental disorder in children and adolescents characterized by a persistently irritable or angry mood and frequent temper outbursts that are disproportionate to the situation and significantly more severe than the typical reaction of same-aged peers. DMDD was added to the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) as a type of mood disorder diagnosis for youths. The symptoms of DMDD resemble many other disorders, thus a differential includes attention deficit hyperactivity disorder (ADHD), oppositional defiant disorder (ODD), anxiety disorders, childhood bipolar disorder, intermittent explosive disorder (IED), major depressive disorder (MDD), and conduct disorder.
The neuroscience of sleep is the study of the neuroscientific and physiological basis of the nature of sleep and its functions. Traditionally, sleep has been studied as part of psychology and medicine. The study of sleep from a neuroscience perspective grew to prominence with advances in technology and the proliferation of neuroscience research from the second half of the twentieth century.
Sleep deprivation – the condition of not having enough sleep – is a common health issue for students in higher education. This issue has several underlying and negative consequences, but there are a few helpful improvements that students can make to reduce its frequency and severity.
Sleep is known to play an important role in the etiology and maintenance of bipolar disorder. Patients with bipolar disorder often have a less stable and more variable circadian activity. Circadian activity disruption can be apparent even if the person concerned is not currently ill.
Affect labeling is an implicit emotional regulation strategy that can be simply described as "putting feelings into words". Specifically, it refers to the idea that explicitly labeling one's, typically negative, emotional state results in a reduction of the conscious experience, physiological response, and/or behavior resulting from that emotional state. For example, writing about a negative experience in one's journal may improve one's mood. Some other examples of affect labeling include discussing one's feelings with a therapist, complaining to friends about a negative experience, posting one's feelings on social media or acknowledging the scary aspects of a situation.