Unravelling Addictions: How Do They Develop, and Why Are They So Difficult to Overcome?

Opioids, cocaine, and nicotine are the substances that most quickly lead to addiction. Valentina Vengelienė, Professor from the Life Sciences Center of Vilnius University (VU), warns that it is best not to dabble with these substances at all, not even trying them once, even if we know we have no genetic predisposition to addiction.

According to the researcher, addiction to a particular substance develops when the brain’s function undergoes irreversible changes, resulting in the loss of behavioural control. Addiction is diagnosed when at least three out of a dozen or so recognised symptoms are present. The main signs include an intense craving for the substance, trouble staying away from it, ignoring social responsibilities, and losing interest in other activities.

Why do people constantly seek pleasure?

Prof. Vengelienė, who has been researching addiction to psychoactive drugs for over 25 years, explains that it is natural and instinctive – not only for humans but also for many animals – to enjoy pleasurable experiences and seek to repeat them.

The only difference is that, in their natural environment, animals cannot pursue additional pleasures, as they must spend most of their lives searching for food and watching out for predators. ‘For humans, it’s the opposite: they don’t need to spend the whole day looking for food or hiding from enemies, so they can allow themselves to get intoxicated. Although specific plants in nature produce alcohol and may form part of some animals’ diets, animal bodies can break down such naturally occurring alcohol extremely quickly,’ said the VU scientist.

According to her, throughout evolution, our brains have developed so that specific subcortical structures activate automatically in response to environmental stimuli that are essential for survival (such as food) or associated with danger (such as predators). ‘We automatically react to internal signals like hunger and thirst, as well as external stimuli like cold, heat, enemies, or danger. All of these are perceived as threats to life and trigger automatic and uncontrollable responses. In other words, natural rewards and threats control us, not vice versa,’ explained the neurobiologist.

The brain builds connections (i.e. associations) between a beneficial (or harmful) stimulus and related ‘cues’, such as sights, sounds, or smells that remind us of the reward (or punishment). This is why simply walking past a restaurant can trigger a specific craving.

Certain brain areas across all living organisms have a reward system linked to the perception of pleasure. When we engage in activities that promote survival and well-being, neurons release special chemical messengers called neurotransmitters. There are many types of them, each acting differently, but some (e.g. endogenous opioids) directly affect the brain’s reward system. When their concentration increases in these reward areas, we feel pleasure. This is like the brain’s way of signalling: ‘Yes, this action is beneficial, do it more often!’ That is why we enjoy eating our favourite food or hugging a loved one – these are examples of natural rewards.

‘This brain reward system is designed to reinforce behaviours necessary for our survival, like eating. The neural reward pathways are activated when we see food-related ‘cues’. One of the neurotransmitters involved in this process is dopamine. The release of dopamine stimulates the learning process (meaning that stronger associations are formed), ensuring that eating-related actions will be repeated in the future,’ noted the addiction researcher.

The effect of psychoactive substances is several times stronger

The Professor explains that a similar principle applies to psychoactive substances – they are environmental stimuli that control us. And there are both positive and negative stimuli. ‘Negative stimuli make us protect ourselves (for example, run or avoid danger or pain), while positive stimuli encourage us to meet our basic survival needs (consume, eat, reproduce, communicate). Psychoactive substances act specifically on the brain areas that respond to positive environmental stimuli and push us to consume.’

Psychoactive drugs imitate the natural activation of the brain’s reward system, which is associated with the feeling of pleasure, and stimulate the learning process that ensures that the actions linked to their use are repeated. The only difference is that the effect of psychoactive substances is incomparably stronger than the reward we get from satisfying our survival needs.

‘This is why it’s so hard for us to stick to diets – natural rewards control us rather than the other way round. For the same reason, it is challenging for a person with a genetic predisposition to addiction to give up psychoactive drugs, as the same brain areas are activated several times more strongly than they would be by natural rewards. All this explains why willpower mechanisms often don’t work when it comes to avoiding sweets, alcohol, or other substances,’ explicated the researcher.

A glass of alcohol or a dose of some drug becomes the only source of ‘real’ pleasure, while the parts of the brain that would normally warn us of danger seem to switch off. We lose our natural self-preservation instincts; health risks, financial situation, or even family no longer seem relevant to us. Interestingly, some substances, like nicotine, do not even produce a strong sense of pleasure, and once a person becomes addicted, that pleasurable feeling becomes significantly weaker. Still, the ability of psychoactive substances to control our behaviour remains just as strong.

What determines whether a person will become addicted?

Whether someone becomes addicted after using a particular psychoactive substance depends roughly 50% on genetic predisposition and 50% on environmental factors. If someone tries a ‘strong’ substance, it quickly becomes clear whether they have a genetic predisposition or not. However, according to the researcher, it is possible to figure this out even without experimenting with substances. She suggests thinking about how many aunts and uncles in your family tend to use psychoactive substances. If there are any, and especially if at least one of your parents also uses them, it can be assumed that there is a significant likelihood of a genetic predisposition.

Moreover, Prof. Vengelienė explains that certain environmental factors can also increase the likelihood of developing an addiction; these include growing up in an environment where psychoactive drugs are used, experiencing psychological trauma, or using such substances at an early age.

‘For instance, psychological trauma experienced in childhood can significantly alter the neural networks that shape behaviour and reactions to environmental stimuli. Or if someone grows up in an environment where most of the closest people used psychoactive substances, they may come to see such behaviour as completely normal and start using drugs early. In such a case, their brain networks develop very differently compared to someone who has never seen or used drugs. Neural networks can even be affected before birth – in the womb; high levels of stress experienced by the mother or the use of brain-altering medications during pregnancy may also cause changes in the child’s brain activity.’

Still, the neurobiologist points out that no substance causes 100% of users to become addicted. Some psychoactive substances have a stronger and more immediate effect, while others act less intensely, resulting in a weaker effect. Therefore, addiction to one substance can develop faster and affect a larger percentage of people, while addiction to another may develop more slowly and affect fewer individuals. Usually, about 10–15% of people who try psychoactive substances end up becoming addicted, which is one or two out of every ten drug users.

‘For example, if there are 24 students in the classroom and all of them try vaping electronic cigarettes containing psychoactive substances, at least two of them might already be on a dangerous path that could seriously impact their future. Young people who decide to try these substances just for fun need to understand that they may be making a decision that affects the rest of their lives because overcoming addiction is incredibly difficult,’ stated the VU Professor.

The greatest danger comes from mixing substances

When asked which substances should be particularly avoided, the researcher lists some that can cause addiction very quickly: ‘Cocaine, all opioids, nicotine, and all substances belonging to the group of psychostimulants have strong effects and can trigger addiction in a very short time. Alcohol, marijuana, cannabis, and hallucinogens (such as magic mushrooms) have weaker effects – with these, a larger quantity and longer period of use are usually needed for addiction to develop.’

However, according to the scientist, the most dangerous practice is mixing substances. She emphasises that electronic cigarettes are a major issue because, at times, no one knows precisely what is actually in them. Thus, young people who smoke electronic cigarettes of unknown composition are seriously risking their health and even lives.

‘Mixing multiple psychoactive substances – and not just in electronic cigarettes – is extremely dangerous because they affect different neurons, but the same liver enzymes are needed to break them down. When those enzymes are busy processing one harmful substance, they cannot simultaneously neutralise another toxic one. As a result, the body can’t cope with such a load and becomes overwhelmed, leading to poisoning or overdose,’ said Prof. Vengelienė.

Three symptoms that indicate addiction

A key sign that someone is addicted to psychoactive substances is, first of all, a loss of control over use. This means that a person has such a strong urge to use the substance that they cannot resist and end up consuming too much, for instance, starting to drink and being unable to stop. Another thing commonly seen in addicted individuals is the inability to postpone consumption for a later time. For example, a student may have an important exam the next day and should refrain from consuming alcohol today, but is unable to delay it until after the exam.

The third sign of addiction is neglecting social obligations or losing interest in alternative activities. The individual becomes indifferent to their social environment: family, work, or the harm they cause to others.

‘When a person abandons all social commitments and alternative interests because the substance is stronger than natural rewards, it means they have succumbed to its control – the stronger reward has overpowered the weaker natural one,’ explained the expert.

Long-term use of psychoactive substances causes structural changes in the brain (e.g. neuronal death), especially in the areas responsible for decision-making, learning, memory, and behavioural control. Because of these changes, it becomes increasingly difficult for people to control their addiction despite the negative consequences.

 

Support from the social environment is the best treatment

According to the scientist, overcoming addictions has little to do with willpower or inner strength but rather depends on a person’s willingness to seek treatment and the application of a combined treatment approach.

The main challenge in treating addiction is helping the individual regain control over their behaviour, as this ability is severely impaired in people with a substance use disorder.

‘For example, for someone struggling with addiction, it is several times harder to resist alcohol than it is for a healthy person to stick to a diet. Saying to such a person, ‘just stop drinking’, is like telling someone living in a war zone, where they could be shot at any moment, ‘don’t be afraid’. It’s impossible, as they will still be afraid because fear is a natural response to a real threat. The same principle applies to addiction to psychoactive substances,’ stated Prof. Vengelienė.

For this reason, she considers people who have a genetic predisposition to addiction but manage to stop using alcohol or other intoxicants true heroes. These are individuals who require tremendous support from those around them. The expert claims that the most effective help for someone struggling with addiction is social support (from family, colleagues, and friends).

‘Social interaction is a natural reward for us humans because we are a species that lives in social groups. Therefore, this is perhaps the only natural reward that has a real chance of outweighing the reward provided by psychoactive substances. However, to recover, a person must radically change their daily routine. They cannot stay in the same place, continue the same activities, and simply stop using psychoactive substances. Because this life routine of ‘acquiring the substance, using it, and chasing the next dose again’ fundamentally alters the brain’s structure: some neurons die, neuroplasticity – the brain’s ability to change – greatly diminishes, and the search for the substance becomes a deeply ingrained daily habit tied to structural changes in neural networks. Trying to change this altered brain network and daily behaviour while continuing to live under the same conditions would be incredibly difficult, if not impossible,’ noted the VU scientist.

Thus, she recommends fundamentally changing one’s lifestyle by pursuing new interests – taking up new activities, seeking intense experiences, or embracing new challenges (e.g. climbing a tough mountain peak, building a house, or volunteering abroad).

Unfortunately, a ‘magic pill’ for addiction is unlikely to be developed anytime soon. However, Prof. Vengelienė is contributing to the search for more effective mechanisms for treating addiction. According to her, treatment should combine three components: self-help, psychotherapy, and medication.

‘I would like to contribute to a successful combination of treatments – either by developing a new medication or a new strategy, and to propose trying innovative addiction therapy methods. Every individual is unique – what works for one person might not work for another. That’s why we must seek innovative, more diverse, and more effective treatment methods and medications,’ concluded Prof. Vengelienė.