Throughout the tumultuous relationship between society and drug addiction, myths have long overshadowed the facts. For much of the last century, people living with addiction were not deemed worthy of the same attention as those with other medical needs. Their condition was seen as a decision, and their character “morally flawed”.
Addiction is a disease. It affects the chemistry of our brain and body, and the solution to recovery is healthcare, not willpower.
Drug addiction: understanding the basics
Before we delve in, let’s clear up some of the terminology surrounding addiction. Substance abuse, dependence, and addiction are three terms often used interchangeably in drug discourse, but there are actually some subtle but important differences between them, as detailed by the National Institute on Drug Abuse (NIDA).
- Substance abuse is a pattern of drug use that harms the mental and physical wellbeing of the user.
- Dependence is the physical aspect of addiction, characterised by tolerance and withdrawal symptoms.
- Addiction is a marked change in behaviour, characterised by compulsive drug seeking and use, which is caused by drug-induced biochemical changes.
- Substance use disorder is the preferred term in the scientific community. It is a chronic, relapsing brain disease, and typically encompasses both dependence and addiction.
The repeating cycle of addiction can be split into three distinct biological stages:
- The binge and intoxication phase, where the user experiences the drug’s pleasurable effects.
- The withdrawal and negative affect phase, where the user experiences a negative emotional state in the absence of the drug.
- The preoccupation and anticipation phase, where the user seeks the drug again after a period of abstinence.
The cycle can vary in duration, spanning months for some users and repeating multiple times a day for others. One consistency, however, is the cycle tends to intensify over time – and, with this, addiction changes both the structure and function of the brain.
Addiction in the brain
The ins and outs of how drugs interact with the brain are still being investigated, with much of our existing knowledge based on findings from animal studies. Scientists’ current model of addiction largely focuses on one particular chemical system in the brain – the dopamine system.
Drugs are very good at mimicking the brain’s own chemicals. They can activate certain receptors which tell specific brain regions to amp up the release of dopamine. Being the major neurotransmitter involved in regulating feelings of pleasure, overstimulating the dopamine system with mood-altering drugs can cause a euphoric “high”.
But dopamine isn’t just involved in emotion; messing with this system can have a big impact on our sense of motivation and reward – two factors which play a major role in drug abuse.
The brain is programmed to keep us alive; it rewards life-sustaining behaviours, such as eating and having sex. Shopping, scrolling on Instagram, and eating cake all give us a natural dopamine rush, so we continue to seek out these behaviours in day-to-day life. But common drugs of abuse – nicotine, alcohol, and cocaine among them – trigger a much larger release of dopamine than natural rewards, between 2 and 10 times more.
Not only does this dopamine surge strongly reinforce the behaviour of drug use, but it can also hijack the brain’s reward circuit. With continued drug use, the brain struggles to function at a baseline level and requires more and more of the drug just to feel “normal”. Natural rewards soon become far less pleasurable, and the user will likely feel flat or depressed when not under the drug’s influence.
With this warped sense of motivation, the brain is trained into seeking drugs at the expense of other basic needs. Over time, the user’s sense of pleasure will diminish, but the feeling of “wanting” grows – and the cycle of drug use continues.
No single factor causes addiction
Society is always trying to find something to blame for the prevalence of addiction, whether that be the drug or the user. But if we look at the statistics, it’s clear not every drug user will develop a form of dependence or addiction. It is estimated that over 3 million adults use drugs per year in England and Wales alone, but less than 300,000 UK adults were in contact with drug services between 2020 and 2021. Other research suggests that 10-20% of all drug users never become addicted.
Drug addiction is very real, but it’s not quite as simple as the anti-drug messaging we have been fed since our youth, which implies that any interaction with any illegal substance will send us into an inevitable spiral of drug abuse. The truth is, no single factor can predict whether a person will develop an addiction. There is a complex and often unpredictable interplay of nature and nature at force. Our unique biology versus our lived experiences.
Genetic factors are believed to account for between 40% and 60% of a person’s risk of developing an addiction. There isn’t necessarily an “addiction gene” where substance abuse is a certain trait for those who possess it, but there are a fair few high-risk gene variations. These gene expressions are even being treated as potential drug targets for new therapies.
Another known risk factor for addiction is exposure to traumatic experiences. Either as a coping mechanism or as a form of escapism, it is not uncommon for trauma to lead a person to drugs or alcohol. There is also evidence to suggest that chronic stress disrupts biological pathways involved in impulse control and other addiction behaviours. As one study found, participants exposed to childhood trauma displayed significantly higher levels of dependence on substances such as alcohol, cocaine, and opioids.
What makes a drug addictive?
Although only a small aspect of addiction is about the substance itself, it is important to note that some drugs – namely nicotine, alcohol, cocaine, opioids, and amphetamines – do have a higher potential for abuse than others; it’s not entirely due to the predisposition of the user.
If we compare the prevalence of abuse of cannabis and opioids, data shows that over 20% of heroin users will go on to develop an addiction whereas, for cannabis users, this figure is believed to be less than 10%. Both drugs are believed to activate the reward system and trigger a release of dopamine, but why are opioids so much more addictive?
Ian Hamilton, a senior lecturer in addiction and mental health at the University of York, tells leafie that the route of drug delivery is likely the reason. Opioids are commonly used intravenously (IV), meaning they are injected into the bloodstream, whereas cannabis is typically smoked or vaporised. “Any drug taken IV will have an effect more quickly,” he shares, which has a higher risk of creating dependency. It makes sense; the harder and faster you come up, the more intense the crash – and you’re likely to want to take it again.
That’s not to say cannabis can’t be abused. Cannabis abuse can destroy lives in the same way any other addiction does, but unlike opioids, cannabis dependence and tolerance are much less likely. Cannabis withdrawals are also far milder and more treatable than the withdrawal effects of opioids.
Hamilton also makes the point that cannabis is often combined with tobacco, meaning that “when [users] try to cut down on using cannabis, they experience withdrawal symptoms that they attribute to cannabis, but are likely to be due to tobacco,” he explains. “Although it can be difficult in reality to distinguish which withdrawal symptom is related to which drug.”
Despite the misinformation that continues to circulate, the biological effects of addiction cannot be undone through willpower alone. Effective treatment and management are crucial, but recovery is possible – even at a physiological level.
In one study, published in the Journal of Neuroscience, researchers imaged the brains of five participants with methamphetamine use disorder before and after 14 months of abstinence from the drug. They found that the drug-induced damage to dopamine transporters was reversed, with levels reaching a near-normal value.
In the UK, medical practices and drug services offer a number of different rehabilitative treatments, which often comprise pharmacological and behavioural approaches to recovery. There are a number of known pharmacotherapies, such as methadone, a substitute used to prevent opioid withdrawals and reduce cravings.
Talking therapies have also been shown to effectively manage substance use disorders. Cognitive behavioural therapy (CBT), in particular, is also one of the most common forms of evidence-based treatment used for the treatment of addiction, with evidence suggesting that CBT can improve emotion regulation and reduce addiction behaviours.
There is even accumulating evidence to support the use of psychedelic-assisted psychotherapy in the treatment of substance use disorder. Trials of psilocybin therapy, in particular, have yielded positive results in patients living with alcohol use disorder and nicotine dependence. There are still many legal and clinical obstacles for psychedelic therapy to jump, but some experts believe that this novel approach to addiction treatment could surpass existing interventions.
Where to get help
If you feel that your relationship with drugs is having a negative impact on your life, professional support is available. The NHS has a guide to treatment for drug addiction, with links to drug services local to you.
UK-based mental health charity, Mind, also has a detailed list of useful services for addiction and dependency, which can be viewed here.
If you believe that someone close to you is struggling with substance abuse, there are ways in which you can help. Although it can be incredibly difficult to intervene with someone’s drug use, the NHS has advice for loved ones of people with problems related to substance use.