The biology of addiction

biology of addiction

Seldom do we realize that all our beliefs, perceptions and behaviors are gradually hardwired into the brain. Addictions are also encoded into our brains, with certain structures playing an important role in the genesis of addictive behavior. Below we try to simplify and understand the biology of addiction. It is a great challenge to beat addictive behavior, the knowledge you gain through this article is vital for your fight!

If one were making a list of all the  things that could be addictive, the list would contain mostly rewarding experiences. Alcohol, cocaine, caffeine, nicotine, social network likes, PUBG head shots, kisses and BF1 kills are all intensely rewarding. Despite having varied mechanisms of action and different effects, all rewarding behavior follow a common pathway in producing addiction and dependence. This applies to some some “positive addictions” too, like exercise, reading etc.

Anything that is rewarding has the potential to become addictive. Exposure to novel rewards and drugs of abuse usually begins in adolescence. The brain is primed to receive rewards and modify itself to keep the rewards coming. Most people who abuse drugs or are addicted to technology believe they are in complete control, however, in reality, the opposite is usually true. As the rewards are reinforced, addictive behaviours change neural networks and alter gene expression in ways that make quitting very difficult!

Addictive behavior can be broken down into 3 states

  • The intoxication state – When one is high on a substance, or indulging in a pleasurable activity (playing a computer game, or receiving a like on a photo)
  • The withdrawal state – The immediate period post the high or pleasurable activity.
  • The Anticipation or preoccupation state – Time spent expecting the pleasurable effects of drugs or other pleasurable activities.

During the intoxication stage, there is a robust release of dopamine ( the pleasure hormone) in the nucleus accumbens ( a region of the brain responsible for reward), giving the user intense pleasure, proportional to the subjective “high”. The search for this pleasure now begins, with parts of the fore brain such the orbitofrontal cortex ( usually responsible for civil behavior) urging the user to go to any extent to obtain more of the drug(or more points on a video game) to experience another dopamine rush. All of us have seen people drinking till the time they pass out and people refreshing their page every few seconds for hours on end.

Following the high, comes the low. When the pleasurable effects fade away as the drug washes out of the body, and levels of dopamine fall, leaving the user in a state of negativity. Remember that hangover, or that time when no body liked your photo?

A few hours after the negative affect stage, as the user walks by a bar, or sees someone smoking, or gets a like on a picture, there is a rapid increase in dopamine levels in response to anticipation of drug use which again motivates procuring behavior and use. This the preoccupation stage. In addicted states, the dopamine release during the anticipation and preoccupations states of use exceeds dopamine release during drug use making it impossible for them to find the high they are looking for,  thereby leading to a never-ending search for pleasure!

Regions of the brain such as the insula (craving for food, cocaine, cigarettes) connect bodily sensations to emotions, increasing the subjective emotional significance of drug procurement and use.

Everyone searches for that effect they had from their first cigarette, or their first drink or their first whiff of the magic green. It is sad that this search often ends in a never-ending spiral of disappointment.

Thus continues a vicious circle wherein severe craving and intense anticipation of pleasurable effects, leads to drug use, and intoxication (which can never be as pleasurable as the time before), followed by withdrawal and negative affect, till an environmental or personal cue triggers the anticipation phase again! Even after a period of abstinence from the offending substance or activity the risk of falling back into the bottomless ravine of addiction remains! The brain takes quite some time to rewire itself to a non-addicted state, sometimes years and sometimes more.

Those who are stuck in the cycle of addiction need to be aware of it. Awareness may be the first step in waging war against addictions. This cycle can be beaten only via proactive action directed at disrupting in. Several medications can help break the addiction cycle.


Screaming at someone who drinks a lot, or spends too much time on the internet isn’t going to work! It only makes it easier for the brain to convince them to slip back into the cycle. Those who are addicted require empathy and support. They do not require sympathy and instruction. Being addicted does not make one a bad person, be supportive and seek help. With appropriate behavioral intervention and medications (if necessary), all addictions can be won over. If you are worried about a friend, family or loved one? Please seek help!