Dopamine: The Secret to Addiction

Have you been wondering why people get hooked on cigarettes, durgs, and other substances even if they know that it is really bad for their health? And no matter how they try to stop they can't seem to stay away from it? It's because of our brain's pleasure center, the hypothalamus.

We all know that the hypothalamus controls body temperature, hunger, thirst, fatigue, anger, and our circadian rhythm. The hypothalamus also releases the neurohormone dopamine which is generally responsible for our pleasure seeking behaviors.
According to Wikipedia, "dopamine is commonly associated with the pleasure system of the brain, providing feelings of enjoyment and reinforcement to motivate a person proactively to perform certain activities. Dopamine is released by naturally rewarding experiences such as food, sex, some drugs, and neutral stimuli that become associated with them. This theory is often discussed in terms of drugs such as cocaine, nicotine, and amphetamines, which seem to directly or indirectly lead to an increase of dopamine in these areas, and in relation to neurobiological theories of chemical addiction.” This basically answers why people succumb to different forms of addiction.
Based on my readings and what I have learned in school, our body needs dopamine. When dopamine levels increase significantly, our pleasure seeking behaviors are triggered causing us to act upon and fulfill our pleasures and/or desires. Let's take cigarette smoking, for example. Our body produces enough dopamine for it to be used by our body. Monoamine Oxidase B (MAO B) regulates the production of dopamine in our body. However, when a person smokes, MAO B is inhibited which results in a significant increase in our body's dopamine levels. When the dopamine levels are increased, there would be increased stimulation leading to pleasure. This explains why the more a person smokes, the more pleasure is derived from it. However, a decrease in our body's dopamine levels cause Parkinson's Disease. For those of you who don't know, Parkinson's disease is a degenerative disease characterized by muscle rigidity, tremors, slowing of physical movement (bradykinesia) and, in extreme cases, a loss of physical movement (akinesia). A very popular person currently suffering from this condition is Michael J. Fox.
Remember, our body is a homeostatic system. This means that it must always be in balance, just like yin and yang. If our body is not balanced, then our our body cannot function to it's utmost level of functioning.