Our nervous system controls how we move, sense, think, and respond to the world. It controls all our functions and how we learn. It includes the brain, spinal cord, and a large network of nerves that run throughout the body.

In the short term, many drugs change how our nervous system works to produce their effects. But over time, especially if we’re using a lot or using when we’re young, these changes can cause long-lasting damage to our nervous system increasing our risk of problems. Preventing damage to our brain is important, because damage can take a long time to heal and some damage cannot be reversed.

Some substances, like alcohol, methamphetamine, cocaine, and nicotine, are toxic to the brain and long term use can cause inflammation and damage that can increase the chances of dementia. Alzheimers New Zealand have summarised ten warning signs of dementia. Long term and heavy use of alcohol can cause damage to the brain, leading to problems with eye movements, difficulty with balance and coordination, confusion and memory loss, difficulty making decisions, and loss of brain function.

Drugs, such as cocaine, methamphetamine, and MDMA can cause seizures. Hato Hone St John have information on how to respond to seizures. Other drugs, such as alcohol, benzodiazepines, tramadol, and GHB/GBL/1,4-BD can also cause seizures during withdrawal if it isn’t managed safely. If we have a seizure, we’re more likely to have another one, especially in the next few months. That’s why, in New Zealand, people who’ve had a seizure usually aren’t allowed to drive for at least a year.

Some drugs, such as alcohol and nitrous oxide, can cause nerve damage (in this case it’s called peripheral neuropathy). Peripheral neuropathy is where nerves around the body are damaged, which can affect our senses (whether we can feel touch, pain, and temperature), our movement, and control of our internal organs like our bladder or heart.

Always see a health professional to get checked if you have had a head injury. This is likely to be covered under ACC. The effects of head injuries can affect you for a long time.

Some useful checks are:

  • Noting if you’re finding daily tasks harder than usual. Track if you are:
    • Finding it hard to balance or co-ordinate your movements. These could be things like feeling clumsy, weak, or off-balanced.
    • Forgetting things more often or finding it difficult to concentrate.
    • Experiencing mood swings.
    • Feeling confused.
  • Tracking your sleep. Are you sleeping too much, too little, or waking up often?
  • Changes in the self-checks outlined above.
  • Tingling or numbness in parts of your body.
  • Slurring your speech or trouble finding the right words.
  • Sudden changes in vision (blurry, double, or loss of vision).
  • Feeling faint or dizzy that doesn’t go away.
  • Losing track of where you are or what day or approximate time of day it is.
  • Muscle weakness or tremors (shaking).
  • Extreme moods or seeing, feeling, or hearing things that aren’t there. Check out the mental and emotional health section for more symptoms.  

It can help to take note of these if these symptoms stick around or get worse, as that’s a sign to investigate further.

Doctors are likely to talk with you about your symptoms and lifestyle. If you feel comfortable, sharing what drugs you have used with them can help them provide better care. Consider requesting thiamine from your doctor if you are drinking a lot of alcohol or drinking alcohol daily.

They may:

  • Check your reflexes. Reflexes are reactions from your body in response to something like light or touch without you having to think about it.
  • Check your co-ordination and balance.
  • Ask questions or give you some simple tasks to check how your brain is functioning.
  • Ask you to get blood tests to look for toxins or vitamin deficiencies.
  • Ask you to get a brain scan to check for damage or changes.