We used to claim that addiction is only an effect of improper lifestyle, or just a loss of morality, a sin. However, addiction can be seen on many levels. We can distinguish two types of addiction: psychological addiction and physical addiction.
The first one is connected with a presence of memories including e.g. happiness and blissful atmosphere acquired during the administration of a particular drug. Such kind of addiction is often based on our cultural and ethnic conditioning. In many cultures, alcohol is a sine qua non for existence at every party or, for example, family event. It may be a very strong baseline for running into addiction by reaching for a narcotic.
The second type of addiction is more complicated and more difficult to understand and treat because it is always associated with physiological and biochemical changes in functioning and structure of our central nervous system.
Addiction Reward system: Sex, drugs and Rock N’ Roll
Our brain contains a variety of neuronal pathways, which connect cerebral structures. One of such is the mesolimbic pathway, exhibiting a high concentration of a neurotransmitter dopamine (DA). There are also many other structures engaged with Reward System, our cingulate cortex and amygdala.
Reward system also works in a physiological stadium and is responsible for e.g. our sexual contact, food searching, i.e. all activities which facilitate survival of our species.
Is every reward good for us?
The Reward System is a very complicated structure, and we believe that clou of addiction development lies here, especially in dopaminergic transmission. This kind of synaptic junctions connects brain structures referred to as Ventral Tegmental Area in midbrain and Nucleus Accumbens in the forebrain.
This connection is a grip point for the majority of hard psychostimulants, like amphetamine, MDMA and opiates. Every reward we get is always stimulating this pathway via dopamine.
But not every reward is desired- drugs tend to be a reason of loss of our aurea mediocritas in the reward system. Why?
Chemistry of addiction
DA, like other neurotransmitters, has special receptors intended for itself. When a molecule of DA connects with such receptor, it leads to stimulation of mesolimbic tract and Nucleus Accumbens. After this event, DA is coming back to the cell, and we call it “reuptake”. Common drugs interfere with this process and lead to increased number of DA particles in synapse cleft. It may cause, in consequence, the up-regulation (also increased number) of DA- receptors in compensation mechanism. During drug withdrawal, receptors in make cell transmission increasingly difficult.
However, it is a a very simplified model of addiction. At the molecular level, drug administration leads to overexpression of delta-FosB protein.
What is the role of this process? We still don’t know.
We can also identify genes associated with increased risk of being addicted for example DRD2- gene, PAX-6, or COMT.
Disease needs treatment
We can use a variety of drugs for the the treatment of addiction and withdrawal syndrome. The second condition appears, as a consequence of resignation of drug administering. We can treat symptoms of this and protect a patient before its occurrence. A particular treatment method depends on a substance- object of addiction. E.g. for ethanol we can use: disulphirame, naltrexone, and for heroine, methadone can be efficiently used. Addiction treatment is very chronic and difficult, often subject to failure.