Dopamine is neurotransmitter in the brain that plays vital roles in a variety of different behaviors. The major behaviors dopamine affects are movement, cognition, pleasure, and motivation.
Cocaine is by far the more severe of the two in terms of addiction. Cocaine chemically inhibits the natural dopamine cycle. Normally, after dopamine is released, it is recycled back into a dopamine transmitting neuron. However, cocaine binds to the dopamine, and does not allow it to be recycled. Thus there is a buildup of dopamine, and it floods certain neural areas (3). The flood ends after about 30 minutes, and the person is left yearning to feel as he or she once did (3). That is how the addiction begins. Progressively a tolerance builds up due to the fact that the person is constantly trying to repeat the feeling that he or she had the first time (2). However, the person cannot, because dopamine is also released when something pleasurable yet unexpected occurs (4). After the first time, the person expects the effect, thus less dopamine is released, and the experience is less satisfying. This principal is the foundation of why gambling releases dopamine.
Interestingly, bliss experienced in meditation is also caused by Dopamine. Read on:
Finally I would like to mention an interesting PET scan study, which to my knowledge is the first study to examine dopamine levels during meditation using the radioactive dopamine ligand C-Ralopride. The meditation in this study, Nidra Yoga meditation, involves giving up personal goals and loss of executive control, while attending to internal sensations and withdrawing from action. This study found that there was an increase in dopamine during the meditation sessions, particularly prominent in the ventral striatum. The subjective accounts correlated with a decrease in readiness for action and an increase in visual imagery. They also noted that there was an increase in EEG power in the theta band, which correlated with the increase in dopamine. This paper confirms the widespread effects of meditation, and suggests that subcortical structures such as the thalamus are significantly involved. This change in dopamine levels in those structures that are related to movement is of particular interest, as there are many subjective reports of an improvement in movement after meditation sessions.
The more recent imaging studies show a further indication of the specific brain areas and the electrical changes that are involved in meditation. The attention mechanisms of the DLPC are prominent as are parietal lobe changes which relate to the body image in space. Feelings of bliss and emotional changes certainly correlate with frontal theta activity, some of which will be arising from the anterior cingulate gyrus. Frontal theta also links in with specific attentional frontal lobe mechanisms. The studies relating to changes in dopamine are interesting, as dopamine is also involved in the reward system. It would be interesting to speculate that some of the dopamine changes may be related to the positive affect that flows from meditation sessions. Finally, the relationship of changes in dopamine levels to motor activity is also important and interesting.
Source: The Neuro Science of Spirituality: The Neuroscience of Spirituality (PDF File)
I don’t know if I am on to something here or even if what I am saying makes sense: Do we use meditation in rehab centers? If not can we use meditation to tackle addiction and alcoholism? All ye docs out there, please respond.