This effect has been widely studied, especially due to Attention Deficit Disorder-related treatments.
This is meant to be a research topic, to dump various notes.. until I figure out what things are called and get some decent research done.
Some people are influenced the opposite way by a medication. Research this effect. Check for applicability to becoming tired from caffeine, and such.
Stimulants work by increasing both blood flow and the levels of Dopamine in the Brain, especially the frontal lobes where the brain's Executive Functions take place. They also increase the inhibitory systems of the brain by enhancing Serotonin and Norepinepherine levels. They do not work by having some mystical "opposite effect" on children.
regarding caffeine ∞
Opposite effects ∞
regarding alcohol ∞
An opposite effect is caused by chronic, or long-term, alcohol use. The alcohol in the system may activate enzymes which metabolize a medication faster or sooner than intended, thus lessening the medication's beneficial effects. The enzymes then remain activated, continuing to affect the metabolism of certain medications for several weeks, even after drinking has stopped.
Another risk: enzymes activated by chronic alcohol consumption transform some medications into toxic chemicals that can damage the liver or other organs. Alcohol can also magnify the effects of sedative and narcotic drugs; in other words, if you take a sedative and then drink alcohol, you might get dizzy or drowsy or experience impaired mental skills - adverse effects the medication was not intended to produce.
Ativan Oral ∞
The elderly may be more sensitive to the effects of this drug, especially drowsiness and unsteadiness. Also, the elderly may not experience relief of anxiety with lorazepam. It may have the opposite effect on the elderly, causing mental/mood changes, sleeping problems, increase in sexual interest, or hallucinations.
Like many other drugs, it is possible to build up a tolerance to cocaine, which means people need to take larger and larger doses to achieve the same high. Some people may actually experience the opposite effect - a sensitivity to cocaine - where even tiny amounts are enough to prompt a rush.
Some users find that the drug helps them perform simple physical and intellectual tasks more quickly, while others experience the opposite effect.
https://www.drugabuse.gov/publications/research-reports/cocaine/what-cocaine [ 3 ] was http://www.nida.nih.gov/researchreports/cocaine/cocaine.html