Anxiety is a frequently used term to express worry and concern about things that might happen. Although, in most cases, this is a normal biological response, too much anxiety for too long can be bad for us.
In the longer term, this can impact our health and well-being. If we become overly anxious over, this can result in a diagnosable anxiety disorder. One of the main features of an anxiety disorder is changes in sleep.
As such, the question remains: What is the real relationship between sleep and anxiety? We will also discuss some of the best ways to manage anxiety.
What is Anxiety?
Broadly, anxiety can be described as an anticipatory response to a perceived or real threat. This response results in increased vigilance and physical tension. We also engage in behaviors aimed towards avoiding or minimizing the perceived threat. While there is overlap, we tend to differentiate fear from anxiety. Fear usually comes from a known threat, whereas anxiety comes from an unknown threat or outcome.
Anxiety occurs when the individual identifies a potential threat. This is then weighed up as the difference between the importance/severity of the threat and the perceived ability to cope with that threat. If there is a discordance (i.e., too big a threat or not enough resources to cope with that threat), uncertainty increases, resulting in high anxiety levels. From a biological perspective, this anxiety activates the fight-or-flight response. The concept of the flight-or-fight response was first outlined by Cannon.
He suggested that when under threat, we maximize our resources to either challenge it or run away. Either way, this results in the production of adrenalin and cortisol. Adrenalin is a fast-acting but short-term chemical hormone. Adrenalin affects the nervous system by increasing blood flow throughout the body. This, in turn, makes the heart beat faster and our breathing shallow while increasing oxygen to the muscles. The extra oxygen produced results in increased power and clarity. This occurs in our main physical systems to provide a boost to the existing resources we have. The result is the optimization of our immediate response to the threat (e.g., running speed, strength, enhanced senses).
Cortisol is a slower-acting but longer-lasting chemical hormone. It boosts blood sugar levels, resulting in a higher prolonged state of physical and mental arousal. The cost of producing adrenalin and cortisol in this context, however, can be significant. To harness this additional energy, a temporary reduction in the capacity of other biological systems occurs. For example, the immune system’s ability, digestive system, and reproductive system to self-regulate reduces.
When too much adrenalin or cortisol is produced, or the response is prolonged, this can damage the body. This is due to the ongoing dysregulation of those systems not involved in an immediate response. As we can see, in the main, anxiety is a normal adaptive response. It prompts us to action and promotes survival. That said, anxiety should be seen on a continuum from normal to pathological, with anxiety disorders being at the opposite end to normal.
What Are Anxiety Disorders?
All anxiety disorders are characterized by excessive fear and anxiety. Behavioral disturbances usually accompany these. In other words, the anxiety is not proportional to the perceived or actual threat.
Moreover, it results in behaviors specifically aimed to avoid the threat. According to the Diagnostic and Statistical Manual of Mental Disorders (DSM-5 – American Psychiatric Association, 2013), there are currently 12 diagnoses under the main category of ‘Anxiety Disorders.’ Each of which has a different set of symptoms associated. For the present discussion purposes, we will focus on the most common of these; Generalized Anxiety Disorder (GAD).
GAD is defined on the basis of this excessive fear, worry, and anxiety over several events or situations. It should exist for a period of six months or longer. Moreover, the individual with GAD finds it challenging to control these thoughts and feelings. This results in experiencing at least three related symptoms.
- feelings of restlessness or being ‘on edge,’
- being easily fatigued
- difficulties concentrating
- muscle tension
- and/or sleep disturbance
For a diagnosis of GAD, the anxiety must also cause clinically significant distress or dysfunction. This can be reported as anything that interferes with normal day-to-day functioning. Finally, the anxiety should not be better explained by or could be attributed to something else. In this case, it could be the impact of a mental or medical condition (e.g., Post Traumatic Sleep Disorder) or a substance, including a medication (DSM-5, 2013).
How do we measure Anxiety?
There is no single standard biological test for ‘anxiety, although many have been suggested over the years. As such, several different self-report measures exist which measure anxiety.
The most common measure of the symptoms of GAD is the seven-item Generalized Anxiety Disorder scale (GAD-7: Spitzer et al., 2006). The GAD-7 asks a series of questions about how frequently symptoms of anxiety have been experienced over the previous two weeks. Scores are summed, resulting in a score between 0 and 21. Scores at 5, 10, and 15 suggest the presence of mild, moderate, and severe symptoms of anxiety.
Furthermore, a score above 10 is related to a diagnosis of GAD. An alternative is the State and Trait Anxiety Inventory. Unlike the GAD-7, the STAI differentiates between state (present levels) and trait (proneness under general conditions) anxiety. As such, it can be used to determine how anxious someone is presently from how worried they are as a person. This scale uses 40 questions, 20 related to each construct, creating two separate scores.
How common is Anxiety?
In terms of symptoms of anxiety, one recent survey in the US reported approximately 8.2% of the population reported symptoms of anxiety. Of note, this figure more than tripled between 2019 and the early part of 2020, to 30.8%, in the context of COVID-19.
The diagnosis of GAD is lower, with a prevalence of around 3.7% across the globe. The first onset of GAD generally occurs in those in their early 30s. Unlike the other anxiety disorders, however, the prevalence of GAD tends to increase with age.
Several risk factors which increase an individual’s vulnerability for GAD have been identified. These include being female, white, low-income, and/or divorced, separated, or widowed. GAD is also a persistent disorder, with one study showing 40% of individuals with GAD still experiencing symptoms 5 years later.
One of the striking things about anxiety disorders, such as GAD, is the number of people who delay or do not seek treatment. Up to 75% of people with anxiety disorder do not seek treatment at all.
What is the Relationship Between Anxiety and Sleep?
There is evidence that sleep and anxiety can be independent (i.e., sleep can be disturbed in non-anxious people. Conversely, some people experience anxiety but do not have a problem sleeping.
However, these two issues appear to be intimately related, especially within the context of sleep disorders. Between 24-26% of individuals with insomnia also meet criteria for an anxiety disorder. Additionally, between 27-42% of individuals with hypersomnia (an excessive sleep duration) also meet the anxiety disorder criteria. It also appears that GAD is the most frequently observed mental health condition reported by those with insomnia. One study showed an overlap between the two conditions between 60-70%.
Interestingly, another study suggested a 100% genetic overlap between insomnia and GAD. The evidence that subjective sleep (self-reported) is disturbed in those with GAD is quite clear. Whether specific aspects of objectively-defined disturbed sleep are impacted, however, is less well understood. For example, in one review, subjective reports of sleep disturbance (e.g., time awake in bed at night) were associated with GAD diagnosis.
However, the same study observed minimal differences in sleep architecture (the percentages and characteristics of different sleep stages). So, while we can conclude that sleep and GAD are related, the question remains, which comes first?
One of the main challenges when examining the relationship between sleep and GAD is that sleep difficulties are defining features. This is no surprise considering the prominent role of similar neurotransmitters (e.g., GABAergic) in regulating sleep and their dysregulation in anxiety disorders such as GAD. Few studies have examined the causal relationship between sleep and anxiety (generally defined).
In one review, the authors concluded that there were bi-directional relationships between insomnia and anxiety in adults. However, the same review found that childhood sleep problems predicted future anxiety but not vice versa, suggesting problems sleeping come first.
One issue to consider is that although this two-way relationship is observed in adults, few studies account for factors that may influence both sleep and anxiety. This can include depression, caffeine intake, alcohol and substance use, medical conditions, and medication use. For example, the dysregulation of inflammatory processes, commonly observed in those with sleep disorders, can also influence anxiety levels and vice versa.
A significant issue here is the interplay between being awake in a sleeping brain. When we sleep, certain parts of the brain downregulate (go into a standby mode). This is good for us by having a certain amount of time to refresh, repair, and ready our physical, psychological, and emotional systems. However, if we are physically awake at that time, we haven’t got full access to those parts of the brain. This is important when we consider that these parts of the brain include rational thought and problem-solving. As such, anxiety can result through increased catastrophic worrisome thinking at night, cauisng poor sleep.
Moreover, there is a complex relationship between the amygdala, the part of the brain responsible for experiencing emotions, and the medial prefrontal cortex, which is responsible for regulating our emotions during sleep. This is specific to Rapid Eye Movement (REM) sleep.
Studies have shown REM sleep deprivation results in a heightened experience of emotions. This occurs alongside a dampening in the capacity to regulate emotions. Together resulting in an increased anxious response.
How to Reduce Anxiety and Get Better Sleep
There are a wide variety of pharmaceutical options for treating anxiety. While many have been shown to reduce anxiety symptoms, their impact on sleep is more complicated. In many instances, insomnia remains (known as residual insomnia).
One non-pharmacological strategy to decrease anxiety is Progressive Muscle Relaxation (PMR). PMR is a technique whereby an individual tenses the muscles in a particular part of the body, holds the tension for a short duration, and then releases. The individual then moves to the next part of the body, usually in an ascending (head to foot) or descending fashion. Another non-pharmacological method often used to reduce anxiety is cognitive therapy. This is either used alone or within the wider management protocol framework (e.g., Cognitive Behavioral Therapy).
While cognitive therapy might sound expensive, here, the term ‘therapy’ can be thought of as a series of techniques. Many of these techniques can be safely and effectively deployed by the individual. While not an exclusive list, two commonly used cognitive techniques for anxiety are cognitive restructuring and constructive worry time.
Cognitive restructuring involves the individual identifying irrational or unhelpful thoughts or beliefs related to their anxiety. They then challenge the validity of those thoughts, using their own experiences and knowledge. Constructive worry time is a technique whereby individuals give themselves an amount of time to express their worries and concerns. This is usually done by writing them down. The individual then identifies the extent to which each worry and concern can be managed. These three non-pharmacological techniques have been shown to be helpful in the context of anxiety in several studies.
However, their incorporation into Cognitive Behavioral Therapy for Insomnia (CBT-I) is where we see a combined impact on both anxiety and sleep. CBT-I is a multi-component treatment strategy aimed at individuals with insomnia. It is usually delivered over a short period of time (six to eight weeks). It targets dysfunctional attitudes and beliefs but also the behaviors related to those worries and concerns.
CBT-I is now endorsed as the first-line treatment for insomnia. This is whether insomnia exists alone or when it exists with another physical or psychological condition. Data on the outcomes of CBT-I shows not only significant reductions in the symptoms of insomnia but also in symptoms of anxiety. For example, in a recent study, a brief CBT-I treatment resulted in a 50% reduction in anxiety. This was in addition to improvements in insomnia symptoms, sleep, and depression.
Tip’s for a good night’s sleep
- Practicing sleep hygiene– Generally, your bedroom should be dark, cool, and most definitely quiet. Light tells your brain that it’s time to wake up. So to get uninterrupted sleep, set your lights as low as possible. As for the temperature, sleep specialists say that having a cool room (around 65°F or 18°C) is best.
- Be mindful of what you eat and drink– Having a large meal for dinner makes it uncomfortable to sleep. Dinner, ideally, should be taken at least two hours before going to bed. Alcohol should be avoided as it can affect sleep patterns and result in sleep disruption.
- Limit the use of electronics– To get a good sleep, you should stay away from bright screens at least an hour before you go to sleep. The blue light coming from the screen suppresses melatonin, a hormone that helps control one’s sleeping patterns.
- Set your body clock– As much as possible, go to sleep at the same time every night. If you do this regularly, your body clock will adapt to it, helping to establish a sleep cycle.
Unfortunately, sleep and anxiety are uncomfortable bedfellows that often find themselves spending the night together. The evidence shows that having an anxiety disorder impacts your sleep. Conversely, having a sleep problem can impact your symptoms of anxiety. This relationship is most clear in insomnia.
The theories on why anxiety and sleep are so related generally fall in the biological/hormonal domain. This is because many of the same hormones and neurotransmitters affect both sleep and emotion regulation. Whilst there are many different management strategies for anxiety, Cognitive Behavioral Therapy for Insomnia appears to be the most robust when both anxiety and insomnia exist. You can also practice some of the other tips we have mentioned to enjoy a restful sleep.