Why is tolerance to the drug dangerous?
As the user needs more and more drug to achieve the same pleasurable effect as before, and slips into addiction, the brain is fooled into thinking a certain amount of drug is needed to feel normal. At some point, overdose is possible, if not probable. Lets say a person goes into treatment and the brains natural chemical balance is restored, then he/she uses again at the same level they did before, the results can be overwhelming. Overdose occurs, even though they could tolerate the same amount before. What chemistry changes in the brain? When people become drug dependent it is because the reward circuits in the brain have been altered. Neurotransmitter glutamate impacts the reward system and the brains ability to learn. When glutamate levels are manipulated, the brain wants to make an adjustment and this can effect its ability to learn. Cognitive function is lessened by drugs of abuse, which cause a decline in unconscious learning. This unconscious learning, such as the need to eat whe
