Rehab 4 Addiction

The effects of cocaine on the brain

With the intense, pleasurable rush that takes place, and onward effects of repeated cocaine use, the brain undergoes changes.

In this article, we will look at what happens at a molecular and whole-brain level and show why these behaviours take place.

There is evidence that stopping cocaine can allow you to recover, and we will look at this at the end.

Feelings From a Cocaine Hit

If cocaine wasn’t so pleasurable it wouldn’t be one of the most popular recreational illegal drugs in the world.

When smoked, snorted, injected or ingested the substance gives an intense rush of pleasure and for a while after, makes the user energised.

In a party situation (where it is often shared) cocaine can make the user socially confident and fun to be around.

There are negative consequences. As well as feeling high and energised, cocaine users can also feel:

  • Agitated
  • Paranoid
  • Anxious
  • Aggressive
  • Impulsive

Thanks to the great feelings that cocaine allows you to experience, people are tempted to take it again and again. This, combined with long term changes in the nervous system, make it addictive as well.

Over longer periods of repeated use, the user can experience amongst other things:

  • Mood instability
  • Hallucinations
  • Flattened mood
  • They can lose weight thanks to not being hungry
  • Deep depression, sometimes to the point of self-harm or suicide

All of these symptoms ultimately appear thanks to the mind being altered by cocaine.

This means that the brain has undergone changes over time. In the next sections, we will look at what happens when cocaine is used and what those changes are.

Intracellular Level

The grey matter of the brain contains billions of nerve cells called neurones. These connect to one another by sending chemicals between the end of one and the beginning of the next.

The gaps between them are called synapses and the chemicals are called neurotransmitters. When a neurone receives a neurotransmitter it will ‘fire’ a signal down the line to the next neurone across another synapse.

The nerve sending the neurotransmitter usually sends over a small amount and then after the message is sent across the synapse it reabsorbs the neurotransmitter in a process called ‘re-uptake’.

This means that in normal life, only a certain amount of the neurotransmitter chemicals will be in the synapse at any one time and the next neurone down will fire the signal as required.

When cocaine is involved, it prevents the re-uptake of the neurotransmitters and consequently all the nerves in a given region fire at the same time due to the flood of neurotransmitters.

This is why the cocaine user feels such a powerful rush – their brain is working at maximum capacity.

Different Neurotransmitters Do Different Things

Cocaine is known to affect the reuptake of four neurotransmitters:

  • Dopamine is part of the reward system in the body
  • Serotonin is also part of the reward system
  • Glutamate (1) is associated with learning and memory
  • Norepinephrine is too

As one can see, both the reward systems and the learning and memory systems of the nervous system are activated by cocaine.

We will discuss this later when we look at the structures of the brain and how they are affected.

Long Term Intracellular Effects of Cocaine

As we discussed earlier, over time, repeated use of cocaine can lead to symptoms associated with mental illness such as low mood and psychosis.

Research (2) has shown that over time of regular cocaine use the neurotransmitter receiving sites on nerves become fewer in number.

This is why the same hits smoked, snorted or injected result in less of an effect, and also why you need a bigger hit each time to get the same high.

Antipsychotic and antidepressant medications work on serotonin re-uptake (selective serotonin reuptake inhibitors – SSRI antidepressants) and dopamine re-uptake (most antipsychotics).

These work in a similar way to cocaine on the reward system, only to a far lesser degree.

As we will show later in this piece, these changes can be reversed with abstinence.

Brain Structures Affected by Cocaine

Given that most neurones pass dopamine, serotonin, norepinephrine and glutamate signals, you can imagine that much of the brain is affected by cocaine at some point.

In this section, we will look at a few key areas where this is known to work in particular.

1. Orbitofrontal Complex – Decision Making

This region of the brain is associated with decision making. During the high, people can be very decisive, though prone to making impulsive decisions such as risky sexual behaviour, and sometimes violence.

Prolonged use of cocaine can leave the user indecisive between hits and can find it hard to make rational decisions.

2. Hippocampus and Prefrontal Cortex – Learning

As hinted in the section above, cocaine affects the way the brain learns through the glutamate system. This is particularly the case in the hippocampus and prefrontal complex (5) regions of the brain which are the main area in which the brain learns new things.

One of the things that the brain can learn all too easily is that cocaine is better for pleasure than almost any other action. This is why the prefrontal cortex is so strongly associated with addiction.

3. Prefrontal Cortex and Amygdala – Pleasure Centres

Earlier we showed that dopamine and serotonin are left in high concentrations in the synapses when cocaine is present. The prefrontal cortex and amygdala (3) are two of those centres that give the sensation of pleasure.

The prefrontal cortex is also a learning centre and works with the hippocampus.

Until recently the amygdala was shown to be a brain region associated with fear, and this explains why the negative sensations of paranoia and anxiety emerge both during and after cocaine use.

Does Cocaine Cause Brain Damage?

Though even after long term use it can be reversed, cocaine can cause brain damage.

We have already discussed the effects at the intracellular level where the neurones have fewer sites to receive the rush of neurotransmitters. There are other effects across the whole brain too.

Glucose is the fuel that the brain uses to perform all of its complex operations and calculations. There is evidence that prolonged cocaine use results in reduced metabolism (‘burning’) of this fuel.

Starved of the fuel, neurones will fire more slowly, and in some cases without glucose can die.

Autophagy(4) is a process where a neurone will cease to work and die of its own accord. With cocaine present in the brain, another region sends signals to certain neurones to shut down and to die.

Over a long period of time this can result in measurable amounts of grey matter disappearing from the brain (5).

Even After Prolonged Use the Brain Can Recover

So, here’s the good news. Research has shown (5) that after a period of abstinence, grey matter volumes increase in the parts of the brain that have been damaged by cocaine abuse.

This research compared the brains of those who had been cocaine users with brains of those who had not used and showed non-users didn’t have the same rate of grey matter growth in the same timeframe or speed.

What was particularly interesting is that the grey matter in areas of learning regrows during the critical period of abstinence required to achieve long-term abstinence.

The authors suggested that this therefore could be a perfect time to undergo therapy to learn new ways of enjoying life without cocaine.

This adds to other research over the years that shows that in the synapses, the cells that had reduced amounts of neurotransmitter receiving sites develop more as they recover from prolonged cocaine use.

With a period of abstinence, in most cases, the user will recover their ability to think properly and regain the ability to feel pleasure from things like food, exercise and sex.

Their mental stability will improve too. This means that there is hope for the individual for a fulfilling life after their spell of addiction and despair.

Though there are not any medications licensed for cocaine withdrawal (other than symptomatic relief such as antidepressants and so on), there are well established talking therapies that can help.

Cognitive Behavioural Therapy (CBT) and couples therapy are good ways to move on from cocaine abuse and with support, the cocaine user can move on.

You can learn about cocaine rehab here.

References

[1] Cocaine-induced neuroadaptations in glutamate transmission https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5413205/

[2] How does cocaine produce its effects? https://www.drugabuse.gov/publications/research-reports/cocaine/what-are-some-ways-cocaine-changes-brain

[3] Scientists identify brain circuit that drives pleasure-inducing behavior https://news.mit.edu/2017/brain-circuit-pleasure-inducing-behavior-0322

[4] New Evidence in Mice That Cocaine Makes Brain Cells Cannibalize Themselves https://www.hopkinsmedicine.org/news/media/releases/new_evidence_in_mice_that_cocaine_makes_brain_cells_cannibalize_themselves

[5] What Happens to the Brain During Recovery from Cocaine Use Disorder? https://www.recoveryanswers.org/research-post/brain-recovery-cocaine-use-disorder/

boris

Boris is our editor-in-chief at Rehab 4 Addiction. Boris is an addiction expert with more than 20 years in the field.  His expertise covers a broad of topics relating to addiction, rehab and recovery. Boris is an addiction therapist and assists in the alcohol detox and rehab process. Boris has been featured on a variety of websites, including the BBC, Verywell Mind and Healthline.