Drug addiction and abuse

Addiction and abuse can happen when you use an illegal drug, or a prescribed medication in a harmful way. Different drugs give different pleasurable effects. People use many substances casually or more regularly to get a high, or to make them feel good. Drug-induced experiences can come at a high price.

Causes of drug addiction

Most prescribed medications do not cause addiction and do not result in highs. Drugs that do cause addiction (drugs of abuse or controlled drugs) are quite different. Most are illegal, but healthcare providers can legally prescribe some of them in controlled ways.

You can inherit a tendency towards addiction, which means it is passed down in families. But stressful life circumstances and personality may also play a role.

  • This information is not about medicinal cannabis.

    There are 3 common forms of cannabis, depending on what part of the plant is used. These are marijuana, hashish and hash oil.

    Cannabis can be smoked:

    • as joints
    • in a pipe
    • in a vaporiser
    • using a water pipe or bong
    • using knives on a stove element

    It can also be eaten in foods. Some people also mix cannabis with tobacco when they smoke it.

    Most people who use cannabis do not use it often. They never develop problems in their lives from its use, and do not have withdrawal symptoms.

    Driving while high (stoned) is dangerous and illegal. If the police pull you over while driving after taking drugs, you may lose your license or face a criminal conviction.

    Mental symptoms

    Some people who use cannabis regularly find that they struggle with poor mood or mood swings. They also have poor motivation, irritability, and poor sleep.

    Physical symptoms

    People who use cannabis can become physically addicted, especially people who use it every day.

    These people may develop unpleasant withdrawal symptoms if they have a day without cannabis or try to cut down or quit. Heavy users of cannabis can become paranoid and fearful. This usually settles down when the drug effect wears off.

  • Hallucinogens or psychedelic drugs can change the way you see the world. They affect your senses, so you might hear or see things that are not there, or feel things differently. This is called tripping.

    More than any other drug, the effects of hallucinogens vary from person to person. The effects also depend on your size, your mood and other things in the environment. You cannot know if you will have a good trip or a bad trip. The effects of the drug usually last between 3 and 5 hours, but can last as long as 12 hours.

    Long term, you may have flashbacks. These can happen at any time after taking the drug. Taking other drugs can trigger them, as well as fatigue or heavy exercise.

    Heavy use of LSD can affect your memory. It may also increase your risk of serious mental disturbance.

    Taking these drugs in an unsafe environment can cause accidents or death. This includes driving, or if you are near a hazard such as water, a high ledge or fire. If someone is putting themselves or others in danger while taking these drugs, you should call 111 and ask for the police.
  • Healthcare providers prescribe opioids to treat strong pain. They are most often used:

    • in hospitals or hospices
    • after operations
    • when a person has a terminal illness like cancer.

    In these cases, taking opioids is completely appropriate.

    People can also use opioids as drugs of abuse because they can give a feeling of pleasure.

    Sometimes a person is introduced to opioids in a social situation. Other times they step up to opioids after getting comfortable using a less dangerous drug. They can also get hooked after using opioids for pain relief. However they started, if a person misuses opioids, they are likely to become addicted to them.

    Getting opioids

    Some people with opioid addictions get opioids from their healthcare provider under false pretences. This is called drug-seeking. Other people get them through a friend or by buying them on the street.

    Buying or selling opioids is illegal. So is prescribing opioids for a person who is addicted. 

    Types of opioids

    There are many different types of opioids. The most common ones are:

    • oxycodone
    • codeine
    • DHC
    • heroin
    • fentanyl
    • pethidine
    • morphine
    • methadone.

    When a person is in pain, these drugs stop them experiencing the pain. They work by blocking the pain message in their brains. When they are not in pain, the opioids give them a feeling of pleasure, or a high.

    Taking opioids

    Opioids can be swallowed, sniffed (snorted), smoked, injected or applied as patches. Different ways of taking the drugs give different effects. For example, injecting or snorting gives an intense high. Swallowing tablets like morphine give a less intense high.

    Opioids are very addictive. If they are not managed carefully, the person taking them rapidly starts to develop a tolerance and to crave more. They find they cannot quit or reduce the amount they are taking and get bad withdrawal symptoms if they try.

    People often make increasingly extreme efforts to get the drug. This often results in crime, poverty and physical injury. It also often leads to loss of relationships and loss of employment.

    You have a higher risk of having an accident while driving. Driving while high is dangerous and illegal. You could lose your licence or face a criminal conviction.

    While high you could be physically or sexually assaulted.

    If you inject drugs, you have a high risk of contracting blood-borne diseases like hepatitis B and C, and HIV and AIDS.


    Withdrawing from an opioid is usually extremely unpleasant. People addicted to opioids tend to use the drug to avoid the withdrawal symptoms rather than to get a high. It can be very hard to get control of an opioid addiction.

  • Stimulant drugs turn the brain on, giving the user a good feeling and intense energy.

    A person using stimulants may feel sexier, stronger, more courageous and more capable. They may need less food or sleep. They may be frenetically active for days on end, and do far more than they are normally capable of doing.

    When a drug experience goes bad, a person using stimulants may collapse in exhaustion. They may also become aggressive, agitated or even psychotic.

    Driving while high is dangerous and illegal. If the police pull you over while driving and you are high on a stimulant, you may lose your licence or face a criminal conviction.

    It is easy to take too much of a stimulant, and overdoses are common. Overdoses can result in heart pain or palpitations, seizures, psychosis or death. If you think you or someone else may have overdosed, call an ambulance on 111.

    Types of stimulants

    Common stimulants are those based on amphetamines like methamphetamine (ice, crystal meth, P). These are very different from the prescribed amphetamine Ritalin, which healthcare providers use to treat ADHD.

    Other stimulants that people can abuse are cocaine and ecstasy (MDMA). These work differently from amphetamines.

    Stimulant drugs come in many different forms and people can take them in different ways. They can be swallowed as tablets, sniffed as powder (snorted), injected or smoked in a pipe. Most stimulants are highly addictive.

    People who are addicted to stimulants may lose their jobs, or lose their families. They can damage their health and reputation. They may start committing crimes to get access to more drugs.

  • Synthetic drugs are made in a laboratory. They are designed to give similar effects to other chemicals that give highs.

    Synthetic cannabinoids are made to be like cannabis and give similar effects.

    Synthetic stimulants are similar to amphetamines. They try to give effects similar to drugs like methamphetamine (P) or cocaine.

    The effect that these drugs give depends on the particular batch. It also depends on:

    • what drug they are based on
    • the amount of the drug taken
    • how pure the drug is.

    The drugs can come in different forms, including:

    • tablets or capsules
    • powder
    • crystal
    • liquid.

    They have many different brand names, or street names.

    Synthetic drugs can be very toxic as you cannot know what is gone into the drug or how pure it is. The drug's effects can also be very unpredictable and quite dangerous. If you think you or someone else is having a bad reaction to synthetic drugs, call an ambulance on 111.

    While it was once possible to buy them in shops, synthetic drugs are now illegal due to the harm they can cause. Many people were becoming very sick and even dying, after using these drugs.

    Synthetic drugs are very addictive. They cause a lot of problems for people in Aotearoa New Zealand.

  • A tranquilliser makes a person feel calm and relaxed. If it is used in higher doses, it makes them fall asleep.

    A healthcare provider may prescribe a tranquilliser to help someone with certain difficulties, including:

    • going through a very stressful time
    • getting panic attacks
    • feeling tense
    • struggling with sleep.

    Tranquillisers are only meant to be used for a short time. But for some people, they can become a daily habit and they can get hooked.

    The most commonly abused tranquillisers are benzodiazepines and sleeping tablets. People can abuse them deliberately, or accidentally. They might be prescribed them by a healthcare provider, buy them off the street or get them from a friend.

    Signs of addiction

    Long term use and doses gradually increasing are signs of addiction. If you cannot easily stop taking the drug, or get withdrawal symptoms when you stop, this could also indicate addiction.

    People who abuse these drugs do not always realise that their drug use is harmful. They may feel that they simply cannot sleep or manage their worries without these tablets. They may think they have no choice about taking them. But using drugs to make problems go away does not solve the problems in the long term. Drug taking brings with it a new set of problems.

    Benzodiazepines and sleeping tablets can be very dangerous — especially if you combine them with other drugs or use them at high doses. In these cases, the drugs can cause an overdose. An overdose can lead to hospital admission and sometimes death. If you think you or someone else may have overdosed, call an ambulance on 111.

    Other serious consequences include:

    • difficulty with work performance leading to losing your job
    • difficulty operating machinery resulting in an accident
    • difficulty driving resulting in an accident or losing your licence
    • difficulty managing household and parenting duties.

    If you use the drugs while pregnant or while breastfeeding, they can harm your pēpi (baby).

    Getting tranquillisers

    It is illegal to buy or sell these drugs, and to get them from a healthcare provider under false pretences. It is also illegal for a healthcare provider to prescribe these drugs to an addicted person. If your healthcare provider suspects that your tranquilliser use is harmful, they may refuse to give you further prescriptions. They may also try to support you to withdraw from taking them.


    Withdrawing from a tranquilliser usually happens slowly. It is likely to need medical and nursing support and intensive therapy.

Getting free of drug addiction

Treatment is available if you abuse drugs or are addicted to them. If you are willing to change, your healthcare provider will encourage you to try self help programmes and join community support groups. They may refer you to a support agency that specialises in addiction.

Getting help with alcohol or drug addiction

Alcohol Drug Helpline

Information about addiction, and publicly funded alcohol, drug and gambling treatment agencies in your region.

The Level

Learn from other New Zealanders' experiences, gain insights into your own use and access support to get your life under control.

New Zealand Drug Foundation

Information and advice about sorting out your or someone else's drug or alcohol use. It has information about specific drugs and videos for young people.

Clinical review

This content was written by HealthInfo clinical advisers. It has been adapted for Health Information and Services.

Clinical advisers — HealthInfo (external link)

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