Methylphenidate (MPH) is the most commonly prescribed psychostimulant and is indicated in the treatment of attention-deficit hyperactivity disorder, Postural Orthostatic Tachycardia Syndrome and narcolepsy, although off-label uses include treating lethargy, depression, neural insult, and obesity. In North America it is most commonly known as the brand name Ritalin, which is an instant-release racemic mixture, although a variety of brand names and formulations exist. Methylphenidate is a potent central nervous system stimulant derived from amphetamine thought to exert its effect by enhancing dopaminergic transmission in the brain.
Ritalin, the trade name for methylphenidate, is a medication prescribed for children with an abnormally high level of activity or with attention-deficit hyperactivity disorder (ADHD) and is also occasionally prescribed for treating narcolepsy. It stimulates the central nervous system, with effects similar to but less potent than amphetamines and more potent than caffeine. Ritalin has a notably calming effect on hyperactive children and a “focusing” effect on those with ADHD. When taken as prescribed, Ritalin is a valuable medicine. Further, research funded by the National Institute of Mental Health has shown that people with ADHD do not get addicted to their stimulant medications at treatment dosages. Because of its stimulant properties, however, in recent years there have been reports of its abuse by people for whom it is not a medication. These prescription tablets can create powerful stimulant effects and serious health risks when crushed and then snorted like cocaine, or injected like heroin.

Short-term effects
Ritalin (methylphenidate) is a central nervous system stimulant, similar to amphetamines in the nature and duration of its effects. It is believed that it works by activating the brain stem arousal system and cortex. Pharmacologically, it works on the neurotransmitter dopamine, and in that respect resembles the stimulant characteristics of cocaine. Short-term effects can include nervousness and insomnia, loss of appetite, nausea and vomiting, dizziness, palpitations, headaches, changes in heart rate and blood pressure (usually elevation of both, but occasionally depression), skin rashes and itching, abdominal pain, weight loss, and digestive problems, toxic psychosis, psychotic episodes, drug dependence syndrome, and severe depression upon withdrawal.
Long-term effects
High doses of stimulants produce a predictable set of symptoms that include loss of appetite (may cause serious malnutrition), tremors and muscle twitching, fevers, convulsions, and headaches (may be severe), irregular heartbeat and respirations (may be profound and life threatening), anxiety, restlessness, paranoia, hallucinations, and delusions, excessive repetition of movements and meaningless tasks, and formicaton (sensation of bugs or worms crawling under the skin).
Tobacco is an annual or bi-annual growing 1-3 meters tall with large sticky leaves that contain nicotine. Native to the Americas, tobacco has a long history of use as a shamanic inebriant and stimulant. It is extremely popular and well-known for its addictive potential.
Nicotiana rustica leaves.
Nicotiana rustica leaves have a nicotine content as high as 9%, whereas Nicotiana tabacum (common tobacco) leaves contain about 1 to 3%
A cigar is a tightly rolled bundle of dried and fermented tobacco which is ignited so that its smoke may be drawn into the mouth. Cigar tobacco is grown in significant quantities in Brazil, Cameroon, Cuba, Dominican Republic, Honduras, Indonesia, Mexico, Nicaragua, Sumatra, Philippines, and the Eastern United States.
Tobacco is an agricultural product processed from the fresh leaves of plants in the genus Nicotiana. It can be consumed, used as an organic pesticide, and in the form of nicotine tartrate it is used in some medicines. In consumption it may be in the form of cigarettes smoking, snuffing, chewing, dipping tobacco, or snus.