Methamphetamine is a powerful, highly addictive stimulant that affects the central nervous system. It can come in several different forms, including tablets, powder, or crystals (often called crystal meth or ice).

Methamphetamine can be taken in several ways:

  • Smoking
  • Swallowing (a pill)
  • Snorting
  • Injecting the powder that has been dissolved in water/alcohol

The ‘high’ from methamphetamine starts and fades quickly, so people often take repeated doses, sometimes for several days at a time.


Like many drugs, methamphetamine increases the amount of the natural chemical dopamine in the brain. Dopamine is involved in motivation and creating a feel-good sensation, rewarding behaviour that stimulates this area of the brain. Methamphetamine rapidly releases high levels of dopamine, which reinforces drug-taking behaviour so that the user wants to repeat the experience, which leads to addiction.

In low to moderate doses, methamphetamine can elevate the user’s mood, increase wakefulness and physical activity, and decrease appetite. It can also cause faster breathing, a rapid or irregular heartbeat and increase blood pressure and body temperature.

At very high doses, it can cause psychosis, muscle breakdown, seizures and bleeding on the brain. Chronic high-dose use can lead to unpredictable and rapid mood swings, stimulant psychosis (such as paranoia, hallucinations and delirium) and violent behaviour.

Methamphetamine addiction, and addiction in general, is a disease of the brain that is not caused by a single factor. It is believed that addiction to methamphetamine and other drugs is caused by a number of factors, such as environment, psychology, genetics and brain chemistry. The most common causes and risk factors associated with methamphetamine addiction include:


Being exposed to addiction as part of daily life at a young age and having easy access to methamphetamine may make someone more likely to develop an addiction. Abuse, stress or trauma may also lead an individual to methamphetamine addiction.

People who are susceptible to peer pressure may be more likely to develop a methamphetamine addiction, alongside individuals who engage in risk-taking behaviour.

A family history of drug abuse and/or addiction increases the chances of developing a methamphetamine addiction. In addition, a family history of mental health disorders is known to heighten someone’s risk of developing addictions.

Addiction is a disorder of the brain’s reward system and illness or injury can affect this area of the brain. Mental health issues linked to brain chemistry can also impact on someone’s chances of developing a methamphetamine addiction.

Drug abuse is different to drug addiction. Drug abuse is often the first step on the road to addiction, and methamphetamine abuse can make it difficult for people to handle their usual responsibilities at work and at home. It may also lead people to behave in a way they wouldn’t usually and develop physical side effects.

Addiction means the user has a strong urge to take a drug, regardless of the consequences. An addiction develops once someone becomes more tolerant of the drug and needs to take more to achieve the same results and/or suffers from withdrawal symptoms without it. Methamphetamine is a highly addictive stimulant, and its use can lead to very strong psychological and physical dependence, especially if it is injected or smoked.

Methamphetamine addiction usually causes cravings, which means that, despite understanding that a drug has harmful effects, the person continues to take it.