# Motivation and emotion/Book/2015/Caffeine and anxiety

* Multimedia presentation (3 min)
* Key questions answered within this chapter:
* What are the immediate physiological responses caffeine has on the human body?
* What are the symptoms of caffeine withdrawal?
* What is the Attentional Control Theory of anxiety?
* What is Suffocation False Alarm Theory?
* What are the empirical effects of caffeine and caffeine withdrawal on an individuals level of anxiety?
* How do these effects relate to theory?
* What importance does this research have in the real world?

## Overview

Caffeine is an incredibly popular psychoactive substance typically consumed as a beverage within Western society (Yang, Palmer, & de Wit, 2010). Caffeine has numerous physiological and psychological effects when introduced or removed from the human diet. As such, the effect of caffeine usage on anxiety is an important topic in the field of motivation and emotion.
In living a more effective motivational and emotional life, it is important to make informed decisions when consuming psychoactive substances. In doing so, individuals can minimise the effects that anxiety has on their life. This is particularly important to individuals with existing anxiety sensitivities, as they may not know the negative effects caffeine usage may produce (Pané-Farré, et al., 2015). Additionally, those who are regularly required to participate in cognitive and attentional based tasks should investigate optimal caffeine consumption in regards to their workload (Eysneck, Derakshan, Santos & Calvo, 2007). Many theorists believe it is import to take sensitivities and degree of usage into consideration when discussing the effects of caffeine use and withdrawal on humans (Smith, 2002). Due to this, caffeine along with its effects on anxiety symptoms will be discussed in regards to the general population, addicted users, and individuals whom experience anxiety sensitivity.

## What is caffeine?

Caffeine is a popular psychoactive substance most commonly consumed via coffee, tea or energy drinks within contemporary Western society (Yang, Palmer, & de Wit, 2010). It has a bitter taste and, in its simplest form, is white in colour (Torres, 2009). Chemically, it is considered an alkaloid and has been discovered as a natural component of a multitude of substances including: tea leaves, cocoa beans and coffee beans (Penolazzi, Natale, Leone, & Russo, 2012). When taken in smaller doses caffeine can induce positive effects for the individual (Penolazzi, et al, 2012).
Caffeine has a known ability to restore alertness, improve performance on simple tasks, as well as improve mood and cognition due to it's stimulating effects the central nervous system (Penolazze et al., 2012; Yang, Palmer, & de Wit, 2010). However, like many psychoactive substances, prolonged and high usage of caffeine is addictive and physiological dependence can ensue (Yang, Palmer, & de Wit, 2010). This type of usage can reduce psychological health (particularly in relation to anxiety) and lead to withdrawal effects when regular users discontinue, or miss habitual doses of caffeine (Penolazzi et al., 2012; Yang, Palmer & de Wit, 2010).
A process of physiological changes occur when a person consumes a product containing caffeine. Although differing doses and sensitivities lead to varied physiological and psychological consequences; the initial process is typically as follows. When an individual consumes caffeine, their central nervous system (including the brain and spinal cord) is chemically stimulated (Penolazzi et al., 2012). As a result, activity in the cardio-respiratory system (the heart and lungs) increases (Paton & Beer, 2001). The smooth muscles in the body become relaxed, and production of gastric acid increases; Subsequently, further stimulation of the central nervous system occurs (Paton & Beer, 2001). This can lead to positive and negative consequences depending on the amount consumed, the individual, and their usual caffeine habits.
A positive effect that caffeine can induce is an analgesic effect on the human body; it has the ability to reduce pain (Keogh & Chaloner, 2002). Due to this, caffeine is utilised in some anti-inflammatory medications and is not merely a product for consumption (Keogh & Chaloner, 2002). In relation to this, it has also been noted by research, that caffeine has the ability to increase an individual's pain tolerance and heighten the pain threshold of humans, provided it is utilised in small doses (Keogh & Chaloner, 2002; Paton & Beer, 2001). However, research has yet to broach whether medicinal use of caffeine affects anxiety levels, or if anxiety is only effected via the usually route of consumption.
Further, as a result of caffeine's stimulation of the central nervous system, long term use has been associated with a reduced risk of developing neurodegenerative disorders[factual?]. In contrast, the increased arousal of the cardio-respiratory system is also associated with increased risk of cardiovascular disease (Yang, Palmer, & de Wit, 2010). In light of the short and long term effects of caffeine, as well as its easy accessibility, the effects of usage has stimulated much research.

### What is caffeine withdrawal?

Similar to many other pharmacological agents, prolonged and regular caffeine usage can produce effects of tolerance (Dews, O'Brien, & Bergman, 2002). For some individuals, the typical effects of caffeine would be reduced in comparison to the norm, due to that individual's higher usage and dosage intake (Dews et al., 2002). Thus, if an individual is consuming the caffeine to ascertain a certain effect such as alertness, they have to increase the amount of caffeine to reach the same effect (Dews, et al, 2002). If this cycle continues and a usual dose of caffeine is missed, withdrawal effects become apparent (Dews, et al, 2002).
Withdrawing from an addictive substance, even when as common as caffeine, can be an uncomfortable process (Dews, et al, 2002). Due to this, some individuals consume coffee to alleviate the withdrawal effects; consequently, dependence can occur (Dews, et al, 2002). Caffeine withdrawal can manifest itself in many ways. To classify these withdrawal effects, Ozsungur, Brenner and, El-Sohemy (2009) created a three factor model. This model broke down the fourteen most common manifestations in three catergories: Flu-like Somatic; Fatigue and Headache; and Dysphoric Mood (Ozsungur, et al, 2009). This chapter will only focus on withdrawal specific to dysphoric mood and anxiety.

## What is anxiety?

Anxiety is an uncomfortable emotional and motivational experience (Eysneck, Derakshan, Santos & Calvo, 2007). This typically arises within the general population when a person perceives a threat, most commonly thought of as the fight or flight response (Eysneck, Derakshan, Santos, & Calvo, 2007). It has been theorised by Eysneck and his collogues (2007) that in modern life the stressor triggering the fight or flight response no longer require direct physical threat, it may be anything in which jeopardises the individual's goal. This generally presents as worry or preoccupation about the stressor and if the person is able to still achieve their goal (Eysneck, et al, 2007). As such, an anxious state occurs when the individual is unable to methodically remove the stressor (Eysneck, et al, 2007).

### Theoretical underpinnings of anxiety

[Provide more detail]

#### Attentional Control Theory (Eysneck, Derakshan, Santos & Calvo, 2007)

Several theories have broached the emotional experience of human anxiety, however amongst the most prominent is Attentional Control Theory. Attentional Control Theory focuses on anxiety experienced by the general population and not merely those effected by varying anxiety disorders seen at clinical levels (Eysneck, et al, 2007). This theory focuses on the effects anxiety places on cognitive performance, thus is more central to the effects anxiety has on processing and executive function (Eysneck et al., 2007). The central concept to Attentional Control Theory is that impaired attentional control can generate experiences of anxiety (Coombes, Higgins, Gamble, Cauraugh, & Janelle, 2009).
In accordance with this theory and general consensus, anxiety is an uncomfortable emotional and motivational condition which typically arises in the general population when the individual perceives a threat to his or her person, or an underlying goal (Eysneck, et al, 2007). The current state of anxiety an individual experiences is influenced by a combination of several variables including the situational stressors as well as trait anxiety (Eysneck, et al, 2007). Eysneck and his collogues (2007) theorised that state anxiety is perpetuated by the stressor. The stressor can be considered anything which jeopardises the individual's goal (Eysneck, et al., 2007). Thus, an anxious state occurs when the individual is unable to formulate a effective method to remove the stressor (Eysneck, et al, 2007). When in this position, state anxiety is elevated as individuals have a tendency to consistently worry about the perceived stressor, typically employing mental strategies aimed at reducing anxiety feelings and reaching their goal (Eysneck, et al, 2007).

#### Suffocation False Alarm Theory

This theory is most commonly associated with Panic Disorder, but can easily be extended to anxiety symptoms incurred by caffeine consumption (Preter & Klein, 2007). This theory considers the concept of an over sensitive fight or flight alarm system, which is easily triggered by physiological experiences (Rosenbaum, Pollock, Otto, & Pollack, 1995). Essentially, this theory addresses a number of concepts which temporarily reduce the flow of oxygen into the body (Preter & Klein, 2007). Some ways in which the oxygen absorption is temporarily compromised include: carbon dioxide inhalation; air hunger (usually present individuals with lung diseases such as asthma); smoking; and general disruptions to normal respiratory function (yawning, sighing etc) (Preter & Klein, 2007). In accordance to this theory, these physiological experiences can result in an over sensitive alarm perceiving this as indicative of suffocation, triggering the fight or flight response (Preter & Klein, 2007). In many cases where the alarm should not have been triggered, this results in what is commonly referred to as a panic attack (Preter & Kein, 2007).

### Anxiety sensitivity

Anxiety sensitivity is a trait characteristic which correlates with the fear of physiological arousal sensations (Pané-Farré et al, 2015). This trait is most typically associated with individuals living with an existing anxiety type psychopathology (Pané-Farré, et al., 2015). However the direct relationship between the two is unknown (Pané-Farré et al., 2015). Granted, as caffeine causes physiological changes to the body, individuals whom experience anxiety sensitivity, particularly those with psychopathology such panic disorder have thus been found to have exacerbated anxiety when caffeine has been consumed (Pané-Farré, et al., 2015).

### What effect does caffeine have on anxiety levels?

Heavily noted in research is the production of anxiety-type symptoms which occur amongst many individuals whom consume caffeine (Rogers, et al, 2006). As indicated by the current state of research, for caffeine to raise state anxiety it needs to be consumed at at least a moderate level (Rogers et al., 2006). Rogers et al., (2006), found that moderate intake of caffeine only increases the anxiety levels of individuals whom did not usually consume caffeine (see Table 1). It is generally only when caffeine has been consumed in high dosages of 500-600mgs and above the following concerns are ensued: anxiety; tension; shaking; nausea; and psycho-motor agitation (Paton & Beer, 2001; Yang, Palmer, & de Wit, 2010).
The expression of these symptoms with the consumption of high rates of caffeine is sometimes referred to as caffeine intoxication, particularly when prominent with the additional symptoms of: Insomnia; diuresis; tachycardia; and rambling (Torres, 2009). This most commonly occurs when exceedingly high dosages of caffeine are taken in short periods of time (Torres, 2009). Nevertheless, for some individuals believed to have existing anxiety sensitivity, as little as the consumption of 200mgs can result in these types of symptoms (Torres, 2009). Caffeine intoxication in anxiety sufferers can cause some individuals to experience even more prominent symptoms of psychosis or delirium (Paton & Beer, 2001).
| Categorical Level of Consumption | Low | Moderate | High |
| Caffeine Amount in mg/day | 0-99 | 100-250 | 251-350 or greater |
Caffeine intoxication also relates to another phenomena more relevant to individuals susceptible to anxiety known as Caffeine-Induced Anxiety Disorder (Torres, 2009). This disorder is diagnosed in individuals from the general population whom routinely consume does of caffeine exceeding 200mg per day and subsequently display anxiety related symptoms (Torres, 2009). These individuals contextually have increases in their self-report and observable anxiety symptoms on days in which they consume the caffeine (Torres, 2009). This may present in a number of ways, often similar to the typical cases of clinical anxiety disorders such as: generalised anxiety, panic attacks and obsessive-compulsive features (Torres, 2009).
As such, it is easily understood why anxiety and panic disorder suffers experience flare ups of their condition when consuming copious amounts of caffeine (Yang, Palmer, & de Wit, 2010). Although, large quanities are not always required to induce negative consequences (Pané-Farré, et al., 2015). In fact, individuals prone to experience anxiety sensitivity report drastic increases in anxiety despite consuming small amounts of caffeine (Pané-Farré et al, 2015). As individuals with anxiety sensitivity are more responsive to physiological experiences, it has been theorised that this response is due to the increases of the central lactate that is metabolised into carbon dioxide which caffeine consumption causes (Pané-Farré et al, 2015). Thus, this increase in carbon dioxide within the body could elicit an alarm response if the suffocation alarm within the brain stem in a person with anxiety sensitivity (Pané-Farré et al., 2015). Theoretically, the predicted reaction to this alarm would be similar to what many individuals living with anxiety experience: a panic attack (Pané-Farré et al., 2015). Therefore, for these individuals sensitive to this type of bodily response, small amounts of caffeine may in fact trigger a drastic anxiety related response (Pané-Farré et al., 2015).
In contrast, not all research has been indicative of caffeine consumption resulting in increased anxiety levels (Smith, 2002). Some research from the early 1990s indicated that for most individuals within the general population, caffeine administered in very small amounts can actually reduced the levels of anxiety those individuals were experiencing (Smith, 2002). Although, that being said minimal evidence since the 1990's supports reductions in anxiety due to caffeine. To further that, little research has been conducted to build upon these findings at all. Therefore further experimental research into this area is required to determine the efficacy of these findings.
| Product | Caffeine Mg per Serving |
| Coffee (Brewed) | 135 |
| Coffee (Instant) | 95 |
| Tea (bag) | 50 |
| Lipton Ice Tea (Various Flavours) | 18-40 |
| Mountain Dew | 55 |
| Coca-Cola | 45 |
| Hershey Milk Chocolate Bar | 10 |
| Hershey's Dark Chocolate Bar | 31 |

### What effect does caffeine withdrawal have on anxiety levels?

The withdrawal effects which caffeine can produce are of wide variety in terms of the responses which occur in humans (Dews, et al., 2002). Some caffeine withdrawal effects include the following: headache; fatigue; depressed mood; anxiety; nausea; irritability; jitters; nervousness; craving; psycho-motor disturbance; tension; delirium; vomiting; and impaired performance (Dews, et al, 2002; Paton & Beer, 2001). Due to varsity of the potential withdrawal symptoms, Ozsungur and colleagues (2009) created a three factor model to simplify research. The factor focused on here is the dysphoric mood and anxiety factor which included symptoms such as: foggy cognition; poor concentration; depressed mood; anxiety; nervousness; irritability; and decreases in the perception of well-being.
Due to the uncomfortable psychological effects of caffeine withdrawal on regular users, this area has stimulated an abundance of research along with that of Ozsungur et al. (2009). Past research from as early as the 1990s indicates during this time 10% moderate level caffeine consumers who participated in withdrawal experiments depicted increases of anxiety and depression symptoms when caffeine was removed from their diet (Smith, 2002). Even earlier research conducted in 1969 by Goldstein & Kaizer (Reported in Dews, et al., 2002), found a much higher proportion of caffeine users experienced anxiety upon withdrawal, in this case 76% of the participants. However, this particular study had only 183 participants whom were all female, thus at any level is not generalisable (Dews, et al., 2002). To further this, several studies utilising placebos have displayed only a small percent of the participants actually experienced withdrawal if they utilised caffeine moderately, although increases in the number of individuals experiencing and the severity of withdrawal symptoms appear to increase with amount if caffeine usually consumed (Dews, et al., 2002).
Research has indicated at lower levels of consumption, withdrawal symptoms are usually in relation to caffeine dependence (Dews, et al., 2002). As not all individuals experience withdrawal at the same rate, all studies in the future on the effects of caffeine on anxiety should account for individual differences in sensitivities. Future research should consider if individuals who regularly consume moderate levels of caffeine and still experience withdrawal also have anxiety sensitivity, and thus are more responsive to bodily sensations.

## How does caffeine usage relate to theories of anxiety?
### Attentional control theory (Eysneck, Derakshan, Santos & Calvo, 2007)

In applying Attentional Control Theory to the aforementioned research in regards to caffeine and anxiety, the relationship can appear somewhat circular. Attentional Control Theory depicts that anxiety may arise in response to situational stressers in context with trait anxiety, more specifically in relation with cognitive performance and attentional control (Eysneck, et al, 2007). As this theory hypothesises that impaired attentional control and poorer cognitive performance results in the experience of anxiety, it can be hypothesised that small amounts of caffeine reduce anxiety symptoms as it increases attention and improves cognitive performance (Eysneck, et al, 2007; Smith, 2002).
To further this, anxiety symptoms which co-occur with caffeine withdrawal may also be addressed by this theoretical construct. Withdrawal from caffeine has been noted to impede performance, and its long list of unpleasant physiological responses can only be assumed to negatively effect attentional abilities, particularly individuals whom score highest in Ozsunger and colleague (2009) dysphoric mood factor. Due to this, it may interfere in goals in which require cognitive ability and attention, thus the state of caffeine withdrawal can be considered a threat and increase anxiety symptoms (Eysneck, et al, 2007). However, further research is required as there was internal validity threats in the construction of Ozsunger and Colleague's (2009) model. The most prominent threat is that many individuals believing they are withdrawing from caffeine do not realise they consume small amounts in their diet excluding the main source of caffeine they are removing (Ozsungur et al, 2009). As such, the extent of withdrawal symptoms and the factors these symptoms can be divided into may differ in the general population (Ozsungur, et al, 2009).

### Suffocation False Alarm Theory

Some anxiety induced by caffeine and appearing in the form of a panic attack is believed to occur in response to the increase in central lactate production (Pané-Farré et al., 2015). Simultaneously, carbon-dioxide levels are elevated and trigger an over sensitive suffocation alarm (Preter & Kein, 2007). Individuals whom this theoretical explanation would apply best too, would be those with anxiety sensitivity (Pané-Farré et al., 2015). This is because individuals with anxiety sensitivity tend to fear such physiological changes, and therefore would be more likely to notice even the most subtle increases in carbon dioxide (Pané-Farré et al., 2015; Preter & Kein, 2007).

## Conclusions

In conclusion, it is clear that including caffeine within one's diet is a motivational and emotional dilemma because it makes anxiety symptoms more likely. Caffeine consumption has a variety of effects on individuals depending based upon their personal level of sensitivity, usage frequency and dose (Pané-Farré et al., 2015; Paton & Beer, 2001; Torres, 2009). People with anxiety sensitivity should avoid more than low level caffeine use because caffeine can increase the severity of anxiety symptoms and can induce panic attacks in some individuals (Pané-Farré et al., 2015; Preter & Kein, 2007; Torres, 2009). Individuals experiencing some stress in relation to attentional control and cognition may find ingesting up to a moderate level of caffeine helpful in reducing their anxiety symptoms, a finding which may be particularly relevant to students (Eysneck, et al., 2007; Smith, 2002). It is clear that consuming high levels of caffeine can have negative effects on the human body but can also impact psychological health in the form of anxiety symptoms and disorders (Paton & Beer, 2001; Torres, 2009). Thus, high consumption of caffeine is not recommended. People who are dependent on caffeine and believe that it is elevating their anxiety levels, should consider reducing their intake slowly rather than inducing an immediate withdrawal (Dews, et al., 2002). This will assist in preventing any uncomfortable withdrawal symptoms including anxiety from incurring (Dews, et al., 2002).