Amphetamines reverse some of these symptoms and have been shown to improve brain development and nerve growth in children with ADHD.

Long-term treatment with amphetamine-based medication in children appears to prevent unwanted changes in brain function and structure.

Scientists carrying out a review of 20 studies concluded that stimulants are probably helpful for people with ADHD.

They found that the brain structures of people who took stimulants for ADHD were more likely to resemble the brain structures of people without the condition than to resemble those with ADHD who did not use the drugs.

A review published in Cochrane in 2011 suggested that adults with ADHD might benefit from short-term use of amphetamines, but that they were unlikely to persist with the treatment because of adverse effects. Those who use mixed amphetamine salts, however, were more likely to continue with the treatment.

Narcolepsy

A person with narcolepsy will experience excessive daytime sleepiness and irresistible sleep episodes, called “sleep attacks.”

In a person with this condition, strong emotions can trigger a sudden loss of muscle tone, or cataplexy, which causes a person to collapse and possibly fall down. It also involves frequent and unexpected bouts of sleep.

Amphetamines and amphetamine derivatives have been used in the past to treat narcolepsy.

Due to concerns over their side effects, however, amphetamines are increasingly being replaced by modafinil, a medication that promotes wakefulness.

Obesity

Under the name Benzedrine, amphetamines were first used to treat obesity in the 1930s, due to their appetite-suppressing capabilities.

Fears of the drug’s side effects and its potential for addiction and abuse caused them to fall out of favor for this purpose. In the 1950s, reports of malnutrition, psychosis, and depression on withdrawal caused doctors to stop prescribing amphetamines for weight loss.

Currently, medical professionals do not recommend using amphetamines and their derivatives to help reduce obesity.

However, in 2015, after carrying out a small study, researchers suggested that dexamphetamine might be a safe and effective way of boosting people’s motivation for lifestyle changes that can lead to weight loss.

They proposed a 6-month use of the drug to help people who have not responded to other treatment to improve their diet and increase exercise levels. This, they say, could help curb obesity and related complications, such as diabetes and cardiovascular disease.

Depression

From the 1930s, amphetamine was used to treat affective disorders, obsessive-compulsive disorder (OCD), and schizophrenia.

However, in the 1950s and 1960s, amid growing concern about its adverse effects, it was replaced by newly available antidepressants.

In rare cases, amphetamines are used alongside standard antidepressants to treat some types of depression that do not respond to other treatments, especially in people who also experience fatigue and apathy.

In a study that followed 65 patients taking amphetamines alongside normal medication, 38 “showed significant improvement, in particular with respect to energy, mood, and psychomotor activity.”

According to the authors, side effects were minimal, and no drug dependency was seen.

Risks

Amphetamine can produce many side effects, ranging from mild to severe.

Physical side effects include:

  • low or high blood pressure
  • Raynaud’s phenomenon, where there is reduced blood flow to the extremities
  • erectile dysfunction, and especially frequent or persistent erections
  • rapid heart rate
  • abdominal pain
  • loss of appetite, nausea, and weight loss
  • acne, rash, hives
  • blurred vision
  • dry mouth
  • teeth grinding
  • nosebleed
  • profuse sweating
  • nasal congestion
  • increased likelihood of seizures for susceptible individuals
  • tics
  • faster, deeper breaths, especially in those with other lung conditions
  • difficulty urinating

There may also be psychological effects.

These include:

  • increased alertness and focus
  • apprehension, anxiety, irritability, and restlessness
  • mood swings
  • insomnia
  • changes in libido
  • grandiosity, or an exaggerated sense of one’s own importance
  • obsessive behaviors

In rare cases, psychosis may occur

People who follow the prescribed, therapeutic dose are unlikely to experience severe adverse effects.

There have been fears that long-term use of amphetamines for ADHD could affect brain development, prevent physical growth, and increase the risk of drug abuse later in life. However, animal studies have suggested that this is unlikely.