Methylphenidate is a drug that stimulates the central nervous system (CNS). It is used to treat people (usually children) who are diagnosed with attention-deficit hyperactivity disorder (ADHD) . About 3% to 5% of the general population has this disorder, which is characterized by agitated, hyperactive, and impulsive behavior as well as an inability to focus on tasks. Methylphenidate increases activity in parts of the brain that appear to be underactive in children with ADHD. When used properly to treat ADHD, this drug produces a calming effect that promotes concentration, rather than a stimulating effect. Researchers believe that methylphenidate increases release of the brain chemical dopamine.

Methylphenidate is also occasionally prescribed to treat narcolepsy .

Health Effects

As a CNS stimulant, methylphenidate has effects similar to, but more potent than, caffeine, and less potent than amphetamines and cocaine .

When taken as prescribed, methylphenidate is a valuable medicine. Research shows that people with ADHD do not become addicted to stimulant medications when taken in the form prescribed and at treatment dosages. Another study found that ADHD boys treated with stimulants such as methylphenidate are significantly less likely to abuse drugs and alcohol when they are older than are boys with ADHD who are not treated with this drug.

In people who do not have hyperactivity or ADHD, methylphenidate produces stimulant effects that some people may find desirable. The desire for these effects has led to abuse of this drug by people who are not prescribed it for a medical reason. The desirable stimulant effects include:

  • Appetite suppression
  • Decreased sleepiness and increased alertness
  • Increased focus and concentration
  • Euphoria

However, methylphenidate can also cause negative side effects, including:

  • Nervousness
  • Insomnia
  • Loss of appetite
  • Nausea and vomiting
  • Dizziness
  • Palpitations
  • Headache
  • Changes in heart rate and blood pressure
  • Skin rashes
  • Itching
  • Abdominal pain
  • Weight loss
  • Digestive problems
  • Toxic psychosis and psychotic episodes
  • Drug dependence syndrome and severe depression with withdrawal

Long-term Effects

When any stimulant, including methylphenidate, is abused for a long period of time, the following health effects can occur:

  • Loss of appetite leading to malnutrition
  • Tremors and muscle twitching
  • Fevers, convulsions, and headaches
  • Irregular heart beats and breathing (may be life-threatening)
  • Anxiety, restlessness, paranoia, hallucinations, and delusions
  • Excessive repetition of movements and meaningless tasks
  • The sensation of bugs or worms crawling under the skin (formicaton)

How Methylphenidate Is Taken

As a prescription drug, methylphenidate is taken as a pill or tablet. When it is abused, the tablets are either taken orally or crushed and snorted. Some abusers dissolve the tablets in water and inject the mixture. Complications can arise from injection because insoluble fillers in the tablets can block small blood vessels, which can cause serious damage to the lungs and retina of the eye.