Drugs of abuse have in common the ability to alter our level of consciousness. Could altered consciousness be rewarding enough to lead to substance abuse without euphoria/elevated mood, and how would you test this hypothesis?
Humans begin altering their minds and reality from an early age. An example of this is a child on a tire swing, who wants more, more, more, throws up, and then gets back on the swing. The reward center in the brain is activated enough that the pleasure of the altered state is greater than the consequence of riding on the swing again.
Addiction may be defined as a habit that has gotten out of control. When obtaining a substance becomes so important that one begins to have negative consequences in their life, physically, emotionally, legally, or socially, one must rule out substance abuse from substance dependency.
“After chronic alcohol consumption, the drinker often develops tolerance to at least some of alcohol's effects. Tolerance means that after continued drinking, consumption of a constant amount of alcohol produces a lesser effect or increasing amounts of alcohol are necessary to produce the same effect”
Many chemical substances act on the pleasure pathways in the brain such that they require more and more of the same substance to reach an altered state. This is an example of tolerance. There can become the situation where the individual no longer, becomes altered or high from a substance, but rather will become sick if they do not ingest the addictive substance.
There are numerous studies available about the pleasure pathways and how alcohol works in this area. There are studies using other drugs as well (cigarettes).One could do a replication study using the same controls as one of these studies and test the strength and validity of the study.