Stimulants are substances that are used to enhance brain activity and has a host of mental and physical effects. Due to the psychoactive nature of these substances, stimulants may also have a number of effects on the emotional state.
A stimulant has pronounced effect on the central nervous system, which is the reason it is often used, and it may also influence the activity of the peripheral nervous system. In most cases, stimulants are used to increase alertness, reduce the need for sleep and give a temporary boost in energy. However, certain illicit drugs that are known stimulants are also used for the euphoria it induces due to the disruption of the brain hormones – dopamine, endorphins, norepinephrine and serotonin.
A stimulant is colloquially known as an ‘upper’. It is believed to enhance mental and physical activity, however, these effects are temporary and the following withdrawal period actually hampers functioning. In addition, large quantities and long term use of stimulants may permanently impair mental and physical activity. Stimulants are no longer used frequently in medical treatments except for conditions like depression and ADHD (attention deficit hyperactivity disorder).
Types of Stimulants
The most commonly known and easily available legal stimulants are nicotine and caffeine. The most widely used nicotine-containing product is tobacco and with caffeine, tea, coffee and certain colas are commonly ingested for the stimulant effect. Both have varying degrees of stimulatory effects on the central nervous system.
In terms of prescription and OTC (over-the-counter) drugs and narcotics (illicit substances), the following are commonly used stimulants :
The effect of stimulants are dose dependent and it is not uncommon to see the opposite effects with higher doses of these substances. Alcohol is not a stimulant but a sedative (depressant) on the central nervous system.
Effects of Stimulants
Stimulants act by increasing the secretion of neurotransmitters, particularly dopamine and norepinephrine. It may also enhance the action of neurotransmitters. It induces a heightened state and may cause a state of euphoria (“feel good”, “high” state). However, stimulants also causes restlessness, anxiety and insomnia, especially if it is used in large doses and during the withdrawal period.
Other effects that are more frequently seen in people who use and abuse stimulants include :
- Rapid breathing (tachypnea)
- Rapid heart rate (tachycardia)
- Raised blood pressure (hypertension)
- Raised body temperature (fever)
- Raise blood sugar levels
- Constricted blood vessels in the skin and piloerection (“goose bumps”)
- Muscle tremors/twitching
- Dry mouth
- Dilated pupils (mydriasis)
- Abdominal pain
Hallucinations may occur when there is a sudden and extremely high release of dopamine that is more frequently caused by illicit stimulants (narcotics).
Dangers of Stimulants
Long term and excessive use of stimulants may lead to a :
- heart attack (myocardial infarction)
- abnormal heart rhythm (dysrhythmias)
- muscle damage (rhabdomyolysis)
- kidney failure
With performance enhancing stimulants used by atheletes, death often occurs suddenly as a result of heart failure. This is caused by a combination of the action of the stimulant and action of the sympathetic nervous system during the performance period. With addiction to stimulants, personality changes may be noted. Depression, paranoia, mood swings, sleeplessness and fatigue are common when the person is not using the drug.
Article reviewed by Dr. Greg. Last updated on December 2, 2010