The Neurological Effects Of Caffeine

Short-term benefits of caffeine

As mentioned, any benefits from caffeine consumption will be short lived but they can be experienced with moderate use of caffeine. That means that health disadvantages can be limited by not exceeding 300mg of caffeine intake per day.

Caffeine intake has been shown to aid in arousal due to interaction with certain neurotransmitters in the brain. Increased arousal leads to increased awareness and therefore a better ability to carry out or perform a task. It was also shown that caffeine intake can increase alertness and decrease fatigue levels when taken in moderate to large doses. This increase in alertness has also indicated the possible benefit to sleep deprived drivers' ability to perform driving tasks.

Caffeine intake has also shown to subjectively reduce stress levels, but this was also a very short lived experience since these users increased their caffeine intake to moderate and high doses.

Disadvantages of caffeine 

As mentioned, caffeine seems to increase alertness and reduce fatigue which is the main reason why it is consumed by those who need to perform tasks that need to be completed before a close deadline. The result here is that these people can start suffering from insomnia. 

Excessive or persistent intake of caffeine can lead to impaired cognition and, particularly, impairment in perceptual learning and memory. Even a moderate dose of caffeine can result in impaired motor skills.

One major issue of caffeine intake is that it was shown that high doses of caffeine exposure to developing brain tissue resulted in depressed hippocampal neurogenesis. This means that there was a disruption of neural circuits where adult-born neurons finally become integrated.

A single 300mg dose of caffeine can already cause an increase in tension and anxiety, whereas a 400mg dose increases anxiety when combined with a stressful task. Patients with anxiety related issues, such as panic disorders, were shown to be more prone to symptoms such as nervousness, anxiety, fear, tremors and palpitations when they were administered a low dose of caffeine as compared to patients with mood disorders such as depression.

Patients who consume more than 300mg of caffeine daily are more prone to experiencing auditory and/or visual hallucinations, as compared to those who only consume around 1-2 cups of coffee a day. These hallucinations can occur due to caffeine increasing the physiological effects of stress.

Caffeine can also lead to acute caffeine intoxication which is characterized symptoms of irritability, nervousness, anxiety, headaches, muscle twitching, palpitations and insomnia.

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Some caffeine users have given evidence of withdrawal symptoms caused by stopping caffeine intake, but these were reported to be mild to moderately bearable symptoms which resolved over a short period of time. Caffeine withdrawal symptoms have included anxiety, increased depression and fatigue.