Addictions are phenomena whose roots have a neurological basis Studies on this issue agree that the brain is the axis around which their clinical expression orbits, so it is concluded that some organic nuance always lies behind it.
However, those with an addiction have traditionally suffered from social ostracism and rejection, when it was understood that their problem was the result of personal weakness or even plain and simple evil. This is why they have been singled out and blamed for their situation on countless occasions, while at the same time denying them any option for reintegration.
Nowadays it is known that consumption begins as an unfortunate decision, motivated and supported by personal or social circumstances; but in its “maintenance” various forces participate that are not easy to deal with (anatomical/functional changes in the neurology itself).
In this article we will explore how consumption affects the brain and behavior, so that both its causes and consequences can be detailed in depth. It is from this that we will be able to better understand the “how and why” of a health problem of enormous human and social importance. The goal is to answer this question: How does addiction affect the brain?
The word “addiction” comes from classical languages, and more specifically from the Latin term “addictio”, which literally translates as “slavery”. From the very beginning, therefore, it is inferred that those who fall into its clutches are deprived of the freedom to think and act freely.
Drug dependence constitutes a chronic disorder due to structural and functional modifications in brain tissues whose etiology has two possible sources of identical contribution: genetics and learning (biology can explain 40%-60% of the variance according to comparative studies carried out with monozygotic twins).
There are a series of symptoms that allow the precise detection of addiction: craving (an irresistible desire to consume where it used to be done), tolerance (the need to use an increasingly higher dose of a drug in order to experience the same effect than in its beginnings), the withdrawal syndrome (strong discomfort when the administration of the substance is stopped), the loss of control (excess time allocated to consume and recover from its effects) and the difficulty in stopping the habit despite its negative impact about everyday life.
All of these phenomena can be explained in a simple way by resorting to changes in the brain systems involved. Let’s see it in detail.
The effects of addiction on the brain
All the behavioral/attitudinal symptoms that are evident in people who suffer from addiction have a clear correlate in their brain. And it is that Drug abuse has the capacity to promote neural adaptations that underlie the cognitive and affective experience of those who present it, and that should never be perceived or interpreted as a “pitiful” or “harmful” attitude. Such a judgment is unfair and imprecise, reductionist in every sense, and not at all in line with current knowledge on the issue.
Let’s look at the addictive process from its very beginning, and as in all its phases, a neurological mechanism can be found that gives a good account of it.
1. Home: the hedonic principle
Pleasure is one of the essential drivers of human behavior. It is the spring that triggers the desire to approach a stimulus in the environment, or to repeat a particular adaptive behavior for life. Among them are sex, eating or recreational activity; for which a common brain mechanism is known that promotes their search and achievement. Specifically, in the deepest abysses of this organ you can find a neural network that is “activated” when we experience a pleasant event (or we subjectively perceive as positive): the reward system.
Everything that people can do that generates pleasure inexcusably involves their stimulation. When we eat what we like the most, have sexual relations or simply share happy moments in the company of a loved one; This set of structures is responsible for us feeling positive emotions that encourage us to repeat these behaviors and/or activities on successive occasions For these cases, a discrete rebound in the regional production of the neurotransmitter dopamine would be observed, although within the healthy physiological threshold.
However, when we observe in detail the functioning of the brain while using a substance (any of them), we can see that in this neuronal complex (formed by the nucleus accumbens, the ventral tegmental area and its specific projections to the prefrontal cortex) produces a “massive” discharge of the aforementioned neurotransmitter (dopamine). This activation is analogous to that evident in natural reinforcers, but with one exception: the amount secreted is between two and ten times higher than that motivated by them, as well as much more immediate and clear in the experience.
The result of this process is that the person feels intoxicated by a great sensation of pleasure just after consuming the drug (although the time it takes to break out depends on its chemical properties and the route chosen for its administration), to such an extent that it exceeds that of any reinforcer available in the natural environment. The main problem underlying all of this is that, with the passage of time, what was rewarding would no longer be so; being replaced by the drugs on which one depends. The result is often the loss of very important relationships and the deterioration of work or academic responsibilities.
2. Maintenance: learning
Hyperactivation of the reward system and the associated experience of pleasure is only a first step toward chemical addiction, but not the only one Otherwise, anyone who consumes a substance would become addicted to it from the precise moment it entered the body, which does not happen. This process requires time, and depends on the network of learning that the individual manages to weave with the stimuli and sensations associated with the objective consumption situation. Thus, there is a psychological component that would contribute to forging dependence, along with the neurological and chemical ones.
Dopamine, the neurotransmitter that coordinates the pleasure response, also has a role in memory and learning among its many attributes This happens especially in collaboration with glutamate, which helps trace the functional relationship between drug consumption and its consequences or environmental cues. Thus, the person will not only feel pleasure after using the substance, but will proceed to create a complete map of the environmental and experiential topography of the same moment (what happens and what they feel), which will help them understand their experience and orient yourself when you crave those sensations again (find out how to acquire and administer the drug).
This neurological process forges a cause-effect relationship that constitutes the foundation of addictions, and that is basic in explaining the link between subjective sensations and their connection with the drug used, which will subsequently articulate a motor behavior directed at its search and its consumption (addictive habit). As the person repeats the association, its intensity will progressively strengthen (closer connections between the nucleus accumbens and the prefrontal cortex). These brain changes ultimately translate into the deformation of the original pleasure, which would become a pressing and extremely invasive need
At this point, the person has usually lost motivation for what was once the very center of their life (from social relationships to personal projects), and focuses their efforts solely on consumption. Contributing to all this is the fact that structures of the primitive brain coordinate with those of more recent appearance (neocortex), giving shape to a pernicious alliance that deteriorates a large part of what was left in the past.
3. Abandonment: tolerance and craving
The brain changes associated with consumption on the reward system involve an artificial modification of its natural function, in such a way that the organ tries to adapt to it by generating compensation that reverses it (with the ultimate objective of recovering homeostasis). Thus, when addiction has finally set in, it takes an inevitable toll: each time the drug causes minor effects, so the person is forced to increase the dose to perceive sensations comparable to that of the beginning (tolerance).
Such attenuation effect can be explained as follows: the substance promotes an increase in “dopaminergic availability” in the cleft of the synapses of the reward system, saturating the receptors for it located in the region. In order to correct this functional aberration, there would be a “downward” regulation of them, the result of which would be the reduction of their presence and the psychotropic effect on the way of feeling and thinking. The substance would thus lose its impact on the inner life, and a battle would begin to be fought between the individual (which would increase consumption) and his or her brain (which would compensate for all that “effort”).
At this point in the process, the subject (who is already deeply affected by the neurological changes of the addictive process) would incur a compulsive search for the substance that would displace everything else When this is not available, an intense physical/emotional discomfort would arise, which is called withdrawal syndrome (and which is expressed in a way opposite to the effect that the drug elicits during intoxication). All of this can be even more difficult when the person suffering from dependence does not make changes in the dynamics of their day-to-day life, and continues to live with the same stimuli that they did when they were in the active phase of consumption.
These difficulties result from the participation of two very specific brain structures: the hippocampus and the amygdala. While the first of them makes it possible to create new content in memory, the second is responsible for processing the emotions that arise from our experiences. When fused together, they facilitate craving, that is, an irresistible desire to consume during exposure to environmental cues related to it. This phenomenon would be the result of addictive history, and could be explained simply through classical conditioning (syringes in injecting heroin users, or the simple presence of people who used to accompany her during the acute effect, eg).
Conclusions: a complex process
The process through which an addiction is shaped is usually slow and insidious. In the first months or years, its use is based on the pleasurable sensations secondary to it (reward system), but these soon give way to a reduction in its effects and an impossible battle to relive them (as a result of neuroadaptation). ) in which biology ends up prevailing. Such a process leads to a loss of motivation for everything that was previously enjoyable with a progressive withdrawal from social life and/or from one’s own responsibilities or hobbies.
When this happens (through the network of connections between the nucleus accumbens and the prefrontal cortex), the person may try to leave the cycle. To do this, he must face the general deterioration of his life, as well as the impulses to consume when he is close to discriminating stimuli (related to his personal experience of addiction). It is this last phenomenon that triggers craving, one of the reasons why relapses or slippages occur most commonly. Its effects are due to the action of the hippocampus and the amygdala.
Definitely, Addiction should never be explained by referring solely to the will, since underlying it are neural dimensions that must be addressed The stigma and rejection that many people face when trying to recover from this problem is a dam to their motivation to live a full and happy life again.
