NEUROBIOLOGY OF ADDICTION

What happenes the brain when we are addicted to drugs? And what is the basic mechanisms involved in addictive drugs and addictive behaviours? What we are looking for is the molecular and neurobiological basis of addiction and how does a person gets addicted to illicit drugs?

First thing that we all should know that everything is in our brain. Like Dr. Paul Bloom says; 
'There are many significant pleasures and universal habits that every human enjoys. Because we all like stimulation..’ What we like and why we like it is the main question here. We will draw insight from child development, philosophy, neuroscience, and behavioral economics to reveal the unknowns about our brain.

There is over increase in illicit drug usage in population especially in adolascence and there is no radical treatment for that. All these drugs effect the brain reward system .This statement is not related to moral disorders it is just a brain ilness.To prevent and understand the mechanism we will get a deeper look.

There are two imporatant parts; Lymbic system and Frontal cortex .In past decades scientists did multiple experiments to understand the working principle of brain regions like in James Olds and Peter Milner’s Skinner Box experiment.They introduced a new term ‘Reinforcement’. It is a type of behavior which is reinforced tends to be repeated (strengthened); behavior which is not reinforced tends to be weakened.  
We all as a child tried out a number of behaviors and learned from their consequences. For example, if when you were younger you tried smoking at school, and the chief consequence was that you got in with the crowd you always wanted to hang out with, you would have been positively reinforced (i.e. rewarded) and would be likely to repeat the behavior.

If, however, the main consequence was that you were caught and suspended from school and your parents became involved you would most certainly have been punished, and you would consequently be much less likely to smoke now. Its all about motivational process which occurs in our reward system.

When a desirable stimulus comes up, it stimulates the ventral tegmental area which is in mesoscorticolimbic dopamine system,  it gives output to the amygdala where it may also play a role in avoidance and fear-conditioning.

Here you see that dopamine is the key neurotransmitter and the activator for reward system. It all effects the ventral tegmental area and hippocampus amygdala and ventral pallidium by dopaminergic inputs. At the end using those addictive drugs, projects the limbic brain with dopamine. 

By taking it up to as much as than the normal level. With these levels elevated, patients brain begins to associate the drug with an neurochemical reward. Over time, by artificially raising the amount of dopamine our brains think that it is "normal," the drugs create a need that only they can meet. Dr. Nora Volkow, the director of the National Institute on Drug Abuse says that if a drug produces increases in dopamine in these limbic areas of the brain, then your brain is going to understand that signal as something that is very reinforcing, and will learn it very rapidly. And so that the next time you get exposed to that stimuli, your brain already has learned that that's reinforcing, and you immediately what we call a type of memory that's conditioning, will desire that particular drug.

In adolescence the prefrontal cortex is not connected well thats why tendency of taking risk and illict drug experince gets higher.

From now on we now that why and how it happens. Its in our hands to prevent it...

NAZLI SERIN