Introduction 

Nocturnal panic attacks (NPA) are abrupt episodes of intense fear that occur during sleep, particularly non-rapid eye movement (non-REM) sleep, that cause the individual to wake up in a state of fear. Non-REM sleep is the phase of sleep that involves little brain activity and muscle tone, thus enabling us to mentally recharge.¹ The length of a nocturnal panic attack can vary; it may last only a few minutes, or could last up to an hour.

Although typically discussed less frequently than daytime panic attacks, nocturnal panic attacks affect a number of people. A survey found that as many as 71% of people with panic disorder experience an NPA at least once in their life.⁴ The impact of night-time disruptions caused by NPAs can spill into the individual’s day-to-day life, causing increased anxiety, tiredness, reduced mental health, and a possible reduced quality of life. Understanding the significance of the attacks is imperative for developing effective treatments for those impacted.

Understanding stress and anxiety

What is stress?

Stress is a phenomenon that we all feel at some point in our lives. It is our body’s natural response to feelings of threat, fear or pressure. When faced with these, we may experience a state of worry or tension. How we respond to stress differs between people and this is what influences our well-being.⁶

There are four different types of stress:⁶ 

• Acute stress is a short-term type of stress that we experience in response to an immediate threat. The symptoms of acute stress develop quickly but are short-lasting. We can feel this type of stress multiple times a day, for example, running late to an appointment
• Chronic stress is a prolonged experience of stress that can negatively impact an everyday life. It can be caused by everyday pressures such as work or family-life
• Episodic acute stress refers to frequent episodes of stress that occur in response to a specific event. This could be multiple deadlines approaching, or a recurring illness
• Eustress is often referred to as a “good” type of stress as it keeps us energised, helping us to perform better due to an increase in the hormone adrenaline

 What causes stress?

Many things can cause stress. What causes stress in one person may not affect another; it is entirely dependent on the individual. Common causes of stress may include but are not limited to: a change in life circumstances, uncertainty about the world, a lack of control over something, pressure, or periods of uncertainty. 

What is anxiety?

Like stress, most of us will experience feelings of anxiety during our lifetime. Anxiety is an emotional response to fear or threats, which can manifest in our feelings, appearance and behaviour. It can leave us feeling tense or worried. The severity of anxiety differs between people, and can improve or worsen at any time.

Anxiety disorder is the umbrella term for the group of mental illnesses that leave sufferers in a state of fear and worry. Commonly diagnosed anxiety disorders include:

• Generalised anxiety disorder (GAD) – a long-term disorder characterised by the feeling of anxiety directed towards a range of things
• Panic disorder (PD) – involves experiencing frequent panic attacks for no evident reason. Experiencing panic attacks can be very distressing. Consequently, the sufferer may begin to feel fearful of the attacks, so much so it may trigger them
• Social anxiety disorder – involves experiencing feelings of fear directed at social situations
• Phobias – involve feelings of intense fear and worry that are directed towards a specific situation or object, such as arachnophobia. Individuals with arachnophobia will experience fear and anxiety towards spiders and other arachnids
• Post-traumatic stress disorder (PTSD) – develops in response to a traumatic event. Individuals will experience flash-backs from the event, filling them with feelings of anxiety and fear

Anxiety impacts our emotional and physical state, and our behaviour. Symptoms of anxiety include feelings of tiredness or restlessness, shakiness, trembling, dizzy spells, an inability to concentrate, disrupted sleep, irregular heartbeat, shortness of breath, and concern about the past or future.

Nocturnal panic attacks: characteristics and symptoms

Symptoms

Psychological symptoms of nocturnal panic attacks include feelings of intense fear and worry, a feeling of impending doom or of losing control, and confusion. Common reported feelings of impending doom involve an individual believing that something very bad is going to happen to themselves or another, or that they are dying.

Accompanying the feelings of fear are typically physical symptoms, including sweating, rapid heart hate, shortness of breath, chest pain, nausea, and dizziness.

Differentiation from daytime panic attacks

The biggest difference between nocturnal and daytime panic attacks is, unsurprisingly, the time in which they occur. With nocturnal panic attacks occurring during non-REM sleep, it can leave the individual feeling wide awake and distressed after it has passed, disrupting their sleep. If the attacks persist over time, it can lead to the individual experiencing poor quality sleep, impacting their day-to-day life. In contrast, daytime panic attacks are less likely to disrupt sleep, however, they may still do so.

Like daytime panic attacks, nocturnal ones may occur for no apparent reason. However, typically they occur after a bad dream. They may also occur when an individual is feeling particularly vulnerable before sleep due to perceived threats. To combat this anxiety, they may opt to sleep with the light on.

Relationship between stress, anxiety, and panic attacks

Mechanisms linking stress and anxiety to panic attacks

The interplay between stress, anxiety and panic attacks is complex. Both stress and anxiety can activate the sympathetic nervous system. Responsible for the body's fight-or-flight response, this system slows down non-essential processes preparing the body for a stressful situation. When activated, it causes symptoms such as increased heart rate and faster breathing. These physiological changes, similar to the symptoms of a panic attack, can trigger an actual panic attack, particularly in individuals who are prone to such episodes.

Additionally, chronic stress can make an individual more susceptible to panic attacks, due to the prolonged release of a hormone called cortisol. Cortisol is effective in preparing the body for a threatening situation; either preparing it to fight or to flee. Once the threat has passed, its levels usually drop. However, chronic stress prevents cortisol levels from dropping, causing prolonged alertness, high energy, and consequently, disrupted sleep.

Factors increasing vulnerability to panic attacks

A genetic predisposition may be the cause of panic attacks in some people. A strong association has been found between a number of genes and panic disorder.¹⁷ However, association does not for certain conclude that genetics lead to panic disorder and thus panic attacks. 

Environmental triggers can make an individual more vulnerable to a panic attack. Examples of triggers include social situations, traumatic events, fears, or memories of a past event. However, it is important to remember that panic attacks may not be triggered by anything at all; they just happen.

Psychological and Physiological Mechanisms

Hyperarousal

Stress can lead to hyperarousal, a state of heightened anxiety. This leads to difficulty sleeping and increases the likelihood of a nocturnal panic attack.¹⁹ 

Neurobiological factors

Imbalances in neurotransmitters serotonin and noradrenaline, responsible for regulating mood and stress levels, may lead to panic attacks. 

Certain brain regions are implicated in the regulation of anxiety. The amygdala, a region of the brain responsible for the regulation of fear, is associated with the fight-or-flight response.²⁰ The locus coeruleus, an area in the brainstem, is implicated in many processes that can be linked to anxiety and nocturnal panic attacks, including the sleep-wake cycle, fear and arousal. Too little activation of the prefrontal cortex has been implicated in panic disorders that involve intense fear. In contrast, over activation of the prefrontal cortex may cause anxiety disorders involving obsessions.²⁰

Coping strategies and management

Stress reduction techniques

Addressing stress and anxiety is imperative for the prevention and management of nocturnal panic attacks. Meditation techniques, such as breathing and mindfulness, work by moving the body away from its fight or flight response, and towards a relaxation response, thereby reducing stress. Meditation may be used to prevent a panic attack, or stop one. 

Physical activity is effective in reducing stress hormones and promoting endorphins, leading to an overall increase in mood.²²

Relaxation techniques can be used to relieve stress and tension in the muscles of the body. Examples include breath focus, yoga, massages, tai chi and body scan. These techniques are effective as they boost our focus on the relationship between mind and body.

Anxiety management

Cognitive-behavioral therapy (CBT) is effective in managing anxiety. CBT works by breaking down negative emotional feelings, allowing them to be dealt with individually in a more positive manner. It involves altering the way one perceives a situation or experience so that it is more positive.²⁵

If psychological treatments are unsuccessful, medication may be suggested. A variety of medications can be prescribed; some short term, others long-term. It is important that the benefits and side-effects of a medication are discussed with a GP before it is taken. Selective serotonin reuptake inhibitors (SSRIs), which increase levels of serotonin in the brain, are antidepressants that are commonly also prescribed to help with anxiety. Another type of antidepressants that can be used are serotonin and noradrenaline reuptake inhibitors (SNRIs), which work by increasing levels of serotonin and noradrenaline. If ineffective or unsuitable for an individual, other medications such as anticonvulsants or sedatives can be used.

Sleep hygiene practices

Sleep hygiene refers to your sleep pattern and environment. Establishing good sleep hygiene is important in improving sleep and preventing anxiety. A regular sleep schedule allows the body to get the amount of sleep it needs, and promotes positive attitudes towards sleep. This involves a consistent wake-up time and bed-time, and minimal naps. Creating a positive sleep environment involves minimal distractions and a comfortable bed. Individuals should also avoid caffeine or alcohol before bed (28).

Summary

The effect of stress and anxiety on nocturnal panic attacks is profound, due to the disruption it causes daily, both in daytime and nighttime. Understanding this relationship is important in the treatment of nocturnal panic attacks. A combination of treatments may be used to reduce the severity of the panic attacks, including meditative techniques, physical exercise, CBT, medication and good sleep hygiene practices. Further research is needed in order to improve treatment.