As stress seems to become increasingly present in this modern age, nocturnal panic attacks (NPAs) are on the rise and appear to affect a relatively large number of the global population. Although their cause in some cases may be obvious, for example due to a panic disorder, other individuals may be confused by their manifestation, particularly since they awaken you from your sleep somewhat randomly. It is therefore important to look at biological processes in the brain (the so-called neurobiology) that may occur during panic attacks in the hope of shining light on the cause. If you are interested in how NPAs can be specified in terms of their neurobiology, then please read on.

What are NPAs?

A nocturnal panic attack can be defined as a sudden emergence from a sleeping state with intense feelings of fear and anxiety, an increased heart rate, and the need to gasp for air. This occurs in spite of no threatening stimulus being present. These symptoms, along with chest pains, sweating, and trembling, are similar to those of daytime attacks, however are often described as having a greater intensity at night. Although more common to those with a panic disorder, anyone has the chance of experiencing an NPA; approximately 4% of the population suffer from repeated NPAs.^1,2 

Pathophysiology

There is a strong link with NPAs and mental health conditions such as depression and anxiety, therefore highlighting the possibility of changes in the nervous system such as the brain, since these are regions in which we process fear and regulate mood. Many studies highlight that the autonomic nervous system (the part of the nervous system involved in arousal and fight or flight) is upregulated and this may be due to the dysregulation of hormones required for its control, such as noradrenaline, along with increased sensitivity to stimulants like caffeine.^1,3,4 

Key Neurobiological Factors in NPAs

Neurotransmitters

There are a range of chemical messengers in the human brain that may be implicated in the occurrence of NPAs. These small messengers are termed neurotransmitters as they transmit information in the brain. Panic states have been strongly associated with three main neurotransmitters: serotonin, noradrenaline, and GABA. Serotonin is necessary for the regulation of mood and anxiety and it has been shown that antidepressants that increase serotonin levels help relieve NPA symptoms. Noradrenaline acts to regulate the autonomic nervous system (a dictator of the fight or flight response), and therefore its abnormal action during NPAs appears to promote an increased state of arousal in which panic is more likely to occur. Finally, GABA is an inhibitory neurotransmitter necessary for regulating electrical signals in the brain, and when its role is blocked there may be an excitatory effect in the brain which could increase the likelihood of an NPA.^5,6,7 

Brain Structures

There are also several brain regions that are likely to play a big role in how some are more sensitised to panic during the night. The amygdala, for example, is responsible for processing fear and appears to show increased activity during the experience of NPAs. Therefore, non-threatening stimuli may have more of an effect on an individual resulting in a lower threshold for panic attacks. 

There may also be some abnormalities with a brain region called the hippocampus. The hippocampus is important for our memory and allows for the recall of threatening situations, as well as their analysis and interpretation. It could be the case that this recall is intensified or distorted and therefore, we misinterpret threatening stimuli leading to nocturnal panic attacks that don’t seem to make sense in their manifestation. 

The final brain area we will touch on is the prefrontal cortex. This is a region which appears to be inhibited during NPAs, and this makes sense since it is involved in how our emotions are processed and additionally plays a role in the response of the amygdala.^5,7 

Genetic and Environmental Influences

The neurobiological components discussed so far that can promote the likelihood of NPAs occurring are often a result of genetic and environmental influences. For example, it is proposed that heritability (passing on of genes from generation to generation) dictates whether one will suffer from NPAs by 43%. This could be a simple change in your genetics that is passed on in the family and dysregulates the communication in your brain to promote a panicked state. For instance it may be a change which impacts noradrenaline and therefore leads to an increased fight or flight response. Additionally, it could be that an environmental factor dysregulates the biology within your brain, for example by a severely stressful event causing long term grief leading to increased stress hormone release and an unbalanced system promoting NPAs. Long-term drug and alcohol are also considered to cause NPAs.^1,8 

Neurobiological Assessments/Diagnosis 

Doctors will first run tests to ensure other health complications are not at play, such as heart problems which may display similar symptoms. You should undergo a background evaluation to determine if you experience risk factors that put you at a greater risk of NPAs, such as intensely stressful situations during one's life, anxiety disorders, depression, or substance use disorder. It may be necessary to conduct blood tests to measure components indicative of stress such as stress hormones.⁹ 

Therapeutic Interventions

Many struggle to find methods to provide relief during an NPA, such as breathing exercises, and therefore, it is common that you would be prescribed medication (which are similar to those used for daytime panic attacks). Antidepressants, often referred to as selective serotonin reuptake inhibitors, can show benefit and in some cases may resolve the attacks, but this may take a few months of use. Benzodiazepines are used in response to severe forms of NPAs since they are stronger, but there is the risk of forming a tolerance to the medication. As a result, their prescription is only permitted when really necessary.⁹ 

Cognitive behavioural therapy is an alternative method of treatment showing great promise. This is a relaxed approach in which discussions with psychologists allow them to identify modes of thinking you may carry out in response to a certain stimulus which essentially promotes the likelihood of an attack happening. It is thought this change in thinking subsequently allows for changes in the neurobiology which may promote a balance and completely resolve NPAs.¹⁰ 

Summary 

Nocturnal panic attacks are defined as a sudden emergence from sleep with intense feelings of anxiety, a racing heart, and often profuse sweating and chest pains. There are a variety of impacted processes within the brain which are considered to promote panic attacks during the night. Chemical messengers, such as serotonin, noradrenaline, and GABA, essential for regulating mood, anxiety, the fight or flight response, and general communication across the brain appear to be disrupted promoting the likelihood of a panicked state emerging at night. This can be caused by a mixture of the genes you have inherited which are important for anxiety regulation and environmental factors such as long term stress which may unbalance systems in the brain. Thankfully, there is medication to resolve NPAs, such as antidepressants to re-balance the system, for instance by increasing serotonin levels, along with therapy methods to implement healthy thinking patterns which may benefit biological processes in the brain.