by affecting the brains chemical messenger system. The brain uses neurotransmitters to transmit messages through nerve cells to the rest of the body. These communicate exterior reality to the brain and determine interpretation. However, with LSD, the chemical changes the functioning of the neurotransmitters so that the brain receives inaccurate information in some instances (hallucinations) and also responds to information inappropriately. Thus, paranoia is a common result of the use of LSD in which the individual may be afraid of something that would not normally arouse fear, like a tree. The brain would be processing information incorrectly and communicating a message of fear (Hallucinogens, 1999).
There are other physiological effects of hallucinogens like LSD. For example, it raises heart rate, blood pressure, and body temperature. It causes sleeplessness, agitation, and sometimes convulsions or seizures. It may block important feelings so that individuals are not aware that they have hurt themselves.
Erdtmann-Vourliotis et al. (1999) conducted a study comparing the activation of pleasure centers and other areas in the limbic region of the brain by drugs with high and low addictive potential. Interestingly enough, they learned that LSD and Ecstasy actually activated more of these regions than the drugs with higher addictive potential, such as cocaine and morphine. For LSD, the regions activated included the lateral septum, large parts of the striatum, including the nucleus accumbens
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