Role of Caffeine in Inducing Anxiety by Reducing Brain Serotonin Synthesis Blocking Adenosine Receptors (A1, A2A, A2B, and A3)

Caffeine is well-known for its stimulant characteristics and is included in a wide variety of foods, drinks, and pharmaceutical formulations worldwide. However, the methods by which caffeine exerts its effects on the brain were unknown until the past decade, when the development of strong research tools enabled scientists to explore the drug's neuropharmacological and biochemical characteristics. Serotonin, especially in sensitive people, also tends to decrease anxiety. Most of their biological effects are caused by antagonising all kinds of adenosine receptors (ARs): A1, A2A, A2B, and A3. Serotonin is a key Central Nervous System (CNS) neurotransmitter. The deregulation of the transmission of serotonin in the CNS is known to be associated with many human mental illnesses, including impulsive aggressiveness, depression, and anxiety disorders.