Psychoactive Drugs: An Overview



Psychoactive Drugs: An Overview

Psychoactive drugs affect communication within the Central Nervous System (CNS, Brain and Spinal Cord) and between the CNS and the body. There is two-way communication between the CNS and the motor system (musculature), the endocrine system (the collection of glands within the body which release hormones into the blood supply) the sensory systems, and all of the internal organs.

As you can see, this inter-communication within the brain and between the brain and the rest of the body makes specific psycho-pharmacologic interventions nearly impossible. To prescribe a drug to alter communication in one area, can alter communication throughout the body; hence, the potential for side-effects is immense, and response to medication can vary widely across individuals.

Within the central nervous system, communication within nerve cells (neurons) is mediated electrically, while communication between neurons is mediated chemically. The purpose of the electrical communication within neurons is to regulate the release of chemicals which the neuron uses to communicate with other neurons. The purpose of the chemical communication between neurons is to influence the electrical excitability of the receiving cell. As you can see, this relationship is circular.

The chemicals which the neurons use to communicate with each other are referred to, collectively, as neurotransmitters. Many of these neurotransmitters you may have heard of. Serotonin is the neurotransmitter which is enhanced by Prozac, Paxil, Zoloft, and several other antidepressants. Dopamine is the neurotransmitter which is deficient in Parkinson’s disease, due to the selective death of dopamine releasing neurons. The L-DOPA medication which Parkinson’s patients take elevates dopamine levels in the brain. On the other hand, if the brain is excessively sensitive to dopamine, schizophrenia will result. Antischizophrenic drugs, such as thorazine, reduce dopamine communication in the brain. It should not be surprising that if antischizophrenic treatment is overly aggressive (as to dose) the psychiatric patient can become Parkinsonian. Conversely, if a Parkinson’s Disease patient is over-medicated, he or she can suffer the symptoms of schizophrenia, such as hallucinations. The neurotransmitter, acetylcholine is released by neurons in the base of the brain which degenerate in Alzheimer’s disease.

................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download