咖啡因中毒是一種由高劑量咖啡因所引起的中樞神經過度刺激。咖啡因，世界上消耗量最大的精神藥物，具有高成癮性且能對生理、心理、精神造成損害。咖啡是攝取高劑量咖啡因最普遍的來源，其他來源包含茶、能量飲料、蘇打飲料、巧克力、止痛藥及感冒藥。攝取咖啡因可以提振精神、專注、警覺性與認知能力。根據DSM-5(APA, 2013) 的估計，美國有85%的人會固定攝取咖啡因。儘管咖啡因中毒正常不會持續超過一天，但極高劑量會有立即急救的必要，並可以致命。咖啡因中毒最常見的反應是睡眠受到干擾，青少年和學生飲用能量飲料導致咖啡因中毒的問題在年輕族群中增加。一個人每天攝取超過250毫克的咖啡因及符合過量的標準，根據DSM-5 一罐8-6盎司的能量飲料含有70-180毫克的咖啡因，一瓶energy shot 含有171毫克，24盎司的大容量裝可以高達500毫克，一杯咖啡則含有100-200毫克(Child & de Wit, 2011)。
許多疾病的症狀與咖啡因中毒及其戒斷症狀相似，例如其他會導致身心異常的物質：菸草、酒精或藥物成癮循環中在憂鬱後的輕微興奮，因此微小的差異在診斷上十分重要。睡眠方面的疾病很容易和咖啡因中毒搞混，因為咖啡因也會導致失眠和睡眠障礙，停止攝取咖啡因可能會出現類似躁鬱症的躁動和輕躁症的症狀。焦慮不安的情形也可能因咖啡因而加重，但單靠咖啡因不會導致嚴重的不安。咖啡因中毒可以是以上這些疾病的併發症和前兆。 咖啡因可能造成家庭、社交和工作上的障礙，其症狀會比其他成癮物質來的輕微和難以發現。然而對於從事簡單而反覆的工作的人來說，在疲勞時攝取咖啡因的能獲得精力和警覺性的幫助(Childs & de Wit, 2011)，但對象從事操作儀器這種高精確度的工作的人反而會降低其工作效率，因為咖啡因會使肌肉精準度受損。當一個人咖啡因中毒時，可能會和家庭成員疏離，並在說話時會顯得過度興奮。
在年輕人中提人飲料的濫用情形最為嚴重，我們可以從癲癇、心血管疾病、代謝性酸中毒之類的酸鹼平衡疾病發生率增加來得知(Trabulo, 2011)，咖啡因攝取量的提高也常發生在致力於極限運動的身體鍛鍊者，他們為了改善並突破身體的極限而攝取咖啡因以得到體力，因為咖啡因不是世界反運動禁藥機構所禁止的物質(Poussel, 2013)。現在的研究多專注於含咖啡因產品的潛在中毒風險，很多能量飲料(e.g., taurine, niacin) 添加的咖啡因會提升中毒的風險，因為咖啡因而導致的體重下降也表現咖啡因中毒的影響。
在 DSM-5 中有個重要的改變就是咖啡因成癮及戒斷被列入疾病的一種，可能需要心理上的幫助改善。但是因為咖啡因並沒有被歸類在管制藥品中，咖啡因成癮者可能不認真看待此問題為需要戒除或推託延遲戒除。大多數會尋求降低或停止使用咖啡因的人都是在已經引發健康問題之後，在美國有一個調查針對想要克服咖啡因依賴的人，結果顯示有43% 的人是因為專業醫療人員建議他們戒除而戒除，而高達 59% 的人則是因健康上的原因而選擇戒除(Juliano, Evatt, Richards, & Griffiths, 2012) 大部分咖啡因成癮的治療過程和藥物濫用及酒精成癮相似，戒治所會提供心理和行為上的治療流程。
有些研究指出，咖啡因和降低自殺率有關係 (Lucas et al., 2013) ，此外，咖啡因也會拿來對抗潛在的心理疾病，像是憂鬱或焦慮，也有研究表示在咖啡因戒除的過程中需要輔以心理支持，以降低受治療者可能產生依賴其他上癮物質的自傷行為的風險。
翻譯完成: 2017/08/26 15:31
DSM-5 Category: Caffeine-Related Disorders
Caffeine intoxication is an over-stimulation of the central nervous system caused by a high dose of caffeine. Caffeine, the most consumed psychoactive drug in the world, is highly addictive and can cause physical, mental, and psychomotor impairments. Coffee is the most common source of a high intake of caffeine. Other sources of caffeine are tea, energy drinks, soda, chocolate, analgesics, and cold remedies. Caffeine is taken to improve mood, concentration, alertness, and cognitive function. About 85% of the US population ingests caffeine regularly, estimates the DSM-5 (APA, 2013). Although caffeine intoxication typically does not last for more than a day, very high doses can require immediate medical attention and be lethal. The most common complaint of caffeine intoxication is interference with sleep. Caffeine intoxication is a growing problem in younger age groups due to the popularity of energy drinks among adolescents and students. For an overdose, a person must ingest more than 250 mg, according to DSM-5. An 8-6 ounce energy drink has 70-180 mg, an energy shot 171 mg, and the mega 24-ounce size can have as high as 500 mg of caffeine. A cup of coffee contains 100-200 mg (Child & de Wit, 2011).
Symptoms of Caffeine Intoxication
Symptoms of caffeine intoxication can include nervousness, irritability, increased urination, stomach upset, and hypertension. For a diagnosis of caffeine intoxication under DSM-5, an individual must have consumed a high dose of caffeine in excess of 250 mg and display five or more of the following symptoms: restlessness, nervousness, excitement, insomnia, flushed face, diuresis, gastrointestinal disturbance, muscle twitching, rambling flow of thought and speech, tachycardia or cardiac arrhythmia, periods of high energy, or psychomotor agitation. These symptoms must cause distress or impairment in social, occupational and other forms of functioning, and not be associated with other substance, mental disorder or medical condition. Children or the elderly may experience caffeine intoxication at lower doses.
Risk Factors and Comorbidity of Caffeine Intoxication
Regular coffee users build up a tolerance to caffeine. Less frequent coffee users are more susceptible to caffeine intoxication. An increase in caffeine intake can also lead to intoxication. Caffeine dependence can develop with an intake of one or two cups daily. A number of disorders share similar symptoms as caffeine intoxication and withdrawal so differentiation during diagnosis is important. Other disorders involving substances such as tobacco, alcohol, and medication share symptoms related to the cycle of addiction, which involves mild excited states followed by depressive states. The symptoms of sleep disorders and caffeine can be confused since caffeine can cause insomnia and sleep disturbances. Caffeine withdrawal may appear similar to manic and hypomanic symptoms in psychotic and bipolar disorders. Symptoms of anxiety can be exacerbated by coffee, including nervousness, but caffeine alone is not likely to lead to a diagnosis of severe anxiety. Caffeine intoxication can be comorbid with any of these disorders and be a precursor of mental disorders. Caffeine can cause dysfunctions in family, social, and work life. The symptoms of caffeine intoxication may be more subtle than those of other addictions and harder to identify. While simple, repetitive tasks can benefit from the added energy boost and alertness of caffeine when one is tired (Childs & de Wit, 2011), a person in a job requiring high precision in motor skills such as a machine operator may experience lower performance due to impaired motor skills. A person with caffeine intoxication may be more withdrawn from family members and be overly excited when he/she does communicate. The increasing abuse of energy drinks especially among the young has been identified with an increase in seizures, cardiovascular events, and acid-base disorders such as metabolic acidosis (Trabulo, 2011). An increase in caffeine intake has also been reported in body-builders who often engage in extreme exercise and supplement intake to change a negative and often distorted image of their body. Caffeine is not considered a prohibited substance by the World Anti-Doping Agency (Poussel, 2013). The potential for toxicity of caffeine products is a more recent focus of research. A number of ingredients in energy drinks (e.g., taurine, niacin) present a risk of toxicity. Caffeine-based weight loss products also pose toxicity risks.
Treatment of Caffeine Intoxication
Caffeine blocks adenosine receptors that slow cellular activity while releasing adrenaline and increasing the neurotransmitter dopamine. In extreme cases, the over-stimulation of the nervous system can cause a heart attack and death. In severe caffeine intoxication cases, repeated haemodialysis may be required to reduce caffeine levels. Diuretics may be used to help flush the caffeine out of the body. In most cases, caffeine’s effects are eliminated within the day. Caffeine intoxication is more often treated as part of caffeine addiction and withdrawal. Psychotherapy, talk therapy and group therapy are used. An important change to DSM-5 is the addition of Caffeine Withdrawal as a disorder, recognizing that psychological assistance may be required. Since caffeine is not classified as a controlled substance, persons addicted to caffeine may postpone and/or not make a serious commitment to quit. A majority of persons seeking to reduce or eliminate their caffeine intake do so when it becomes a health issue. A survey of persons seeking to overcome their caffeine substance dependence in the United States found that 43% were advised to quit by a medical professional and 59% were quitting for health-related reasons (Juliano, Evatt, Richards, & Griffiths, 2012). Most people with an addiction to caffeine follow a similar course of treatment as those who suffer from drug and alcohol abuse. Addiction centres and programs provide psychotherapy and behavioral therapy. The treatment of caffeine withdrawal symptoms is part of any successful treatment program. Symptoms include depression, irritability, anxiety, headache, fatigue and difficulty concentrating. Relieving withdrawal symptoms is a primary reason for relapsing. Relapse rates decline in line with the length of abstinence. Headaches within 12-24 hours of withdraw are the major withdrawal symptom. Medication is prescribed for caffeine withdrawal headaches such as aspirin and analgesics. Several studies have made a connection between caffeine use and a lower risk of suicide (Lucas et al., 2013). Furthermore, caffeine may be taken to cope with an underlying mental disorder such as depression or anxiety. Such findings would support the need for psychotherapy support during treatment for a caffeine disorder to lower the risk of self-harm behavior, which could include increasing dependence on another addictive substitute substance.