During use

During use, the person usually feels a sense of wellbeing or euphoria and is alert, energetic, wakeful, extremely confident — sometimes even feeling invincible — with a sense of heightened awareness and increased concentration. Libido (sex drive) and blood pressure often increase. The person may be talkative and fidgety or restless, and will have large (dilated) pupils. Appetite is reduced and wakefulness varies, but might continue for 12 hours or more.

At higher doses

At higher doses, the person might experience tremors, anxiety, sweating and overheating, a racing heart, dizziness, tension, irritability, confusion, teeth grinding, jaw clenching, increased breathing; auditory (hearing), visual or tactile (touch) illusions; paranoia and panic state; loss of behavioural control; or aggression.

In overdose

In overdose (toxicity), the person can experience intense paranoia involving hallucinations (hearing or seeing things that are not there) and delusions (e.g. having a fixed false belief that people or things mean the person harm).

The person can also experience chest pain and shortness of breath; severe headache; tremors; hot and cold flushes; dangerously increased body temperature; muscle spasms; brain haemorrhage (stroke); heart attack and other heart problems; or seizures (fits).

After use (crash period)

A meth binge depletes the chemicals in the brain associated with pleasure, motivation, memory, mood and ability to deal with stressful situations (dopamine, serotonin, noradrenalin). Combined with lack of sleep and inadequate nutrition, irritability, hunger, tiredness, paranoia, anxiety, and depression are common during the crash period.

Long-term use of methamphetamine can result in a number of physical and psychological effects, which are often related to poor diet, lack of sleep, dehydration and ongoing changes to the chemical messengers including:

• weight loss and dehydration relating to poor nutrition or malnutrition; irregular or absent menstrual periods; renal (kidney) problems caused by inadequate fluid intake; chronic sleeping problems; and meth dependence.

• extreme mood swings including depression and possibly suicidal feelings; anxiety; paranoia; and psychotic symptoms including hallucinations and delusions.

• cognitive thinking changes including memory loss, difficulty concentrating, and impaired decision-making abilities.

Other potential harms that could occur as a result of using meth include:

• blood-borne viruses, including hepatitis B and C and human immunodeficiency virus (HIV) from sharing injection equipment.

• infections and damage to veins (cellulitis), if injecting meth.

• heart problems such as irregular heartbeat, weakened heart muscle (cardiomyopathy), bacterial infections of the lining of the heart (endocarditis), and heart attack (myocardial infarction).

• burst blood vessels in the brain (stroke, ruptured aneurysm, brain haemorrhage).

• shortness of breath and dizziness in smokers of ice.

• transmitting a sexually transmitted disease linked to sexual risk taking.

• poor oral health such as gum inflammation (gingivitis) and cavities caused by methamphetamine-induced dry mouth, and damaged teeth due to grinding and jaw clenching.

• feelings that ‘bugs’ are crawling under the skin (tactile hallucinations).

• compulsive skin picking and scratching, particularly on the face and arms, which can increase vulnerability to skin and other infections.

• family and other relationship breakdown; financial problems; loss of employment; and legal problems related to drug driving, dealing, or engaging in other crimes to support continued use.

Methamphetamine users who use several times per week are likely to manifest at least some symptoms of dependence, which is characterised by the following:

• A strong desire or need to take meth.

• Difficulties in controlling when you use, how long you use for and how much you use.

• Using increased doses to achieve the same effects originally produced by a lower dose.

• Important social, occupational or recreational activities are reduced or given up because of meth use, and an increased amount of time is needed to obtain or take meth or recover from its effects.

• Continued use of meth despite clear evidence of harmful consequences. For example, depressive moods after use.

• Experiencing withdrawal symptoms if not using meth.

• Feeling flat or joyless (anhedonia) after stopping use. This is caused by an imbalance in levels of dopamine and can take some time for the balance to be restored.

Physical health

Signs that someone may be experiencing meth toxicity (overdose) include:

• Agitation.
• Overheating and severe fever.
• Disorientation.
• Severe persistent headache.
• Uncoordinated movements.
• Rapid breathing or difficulty breathing.
• Chest pain or heart palpitations.
• Muscle stiffness, tremors and spasms.
• Seizures.

If someone is experiencing these symptoms call an ambulance on 000 (Triple Zero) immediately.

Mental health

If you’re experiencing psychosis and it isn’t subsiding, or if you’re otherwise concerned about your mental health, we recommend seeking professional help. Call the Alcohol Drug Support Line on (08) 9442 5000 or 1800 198 024 (country callers).

If you’ve noticed changes in your physical or mental health and want some advice or support about your meth use contact:

• the Alcohol and Drug Support Line for free non-judgemental telephone counselling on (08) 9442 5000 or 1800 198 024 (country callers).
• visit your local GP.