Final answer:
Your friend is likely experiencing caffeine withdrawal option a is correct, a common reaction to the reduction in caffeine intake for those who previously consumed it regularly. Caffeine affects the central nervous system by blocking adenosine receptors, leading to increased alertness. Withdrawal symptoms include headaches, fatigue, and irritability as the body adapts to the lower caffeine levels.
Step-by-step explanation:
Your friend is experiencing symptoms such as headaches, fatigue, and irritability due to caffeine withdrawal. When a habitual caffeine consumer significantly reduces their intake, they may experience a number of withdrawal symptoms. Caffeine, being the world's most widely consumed psychoactive drug, has notable effects on the central nervous system, including increased alertness and delay of fatigue.
However, when the body becomes accustomed to a certain level of caffeine and then the intake is decreased, withdrawal symptoms can occur.
This is because caffeine blocks the action of a brain chemical called adenosine, which promotes sleep and relaxation, and regular consumption can lead to changes in brain chemistry.
As described in the case study mentioned, excessive consumption of caffeine can lead to dependence and health issues, both physical and mental. Once caffeine intake is reduced, as in the case study of the woman who was advised to decrease her consumption, health improvements can be observed over time. The symptoms your friend is experiencing are consistent with what is known about caffeine withdrawal, a phenomenon that has been documented in the scientific literature and is characterized by symptoms like headaches, anxiety, irritability, and more.