Nicotine - Dependence and Withdrawal

Dependence and Withdrawal

Modern research shows that nicotine acts on the brain to produce a number of effects. Specifically, research examining its addictive nature has been found to show that nicotine activates the mesolimbic pathway ("reward system") – the circuitry within the brain that regulates feelings of pleasure and euphoria.

Dopamine is one of the key neurotransmitters actively involved in the brain. Research shows that by increasing the levels of dopamine within the reward circuits in the brain, nicotine acts as a chemical with intense addictive qualities. In many studies it has been shown to be more addictive than cocaine and heroin. Like other physically addictive drugs, nicotine withdrawal causes down-regulation of the production of dopamine and other stimulatory neurotransmitters as the brain attempts to compensate for artificial stimulation. As dopamine regulates the sensitivity of nicotinic acetylcholine receptors decreases. To compensate for this compensatory mechanism, the brain in turn upregulates the number of receptors, convoluting its regulatory effects with compensatory mechanisms meant to counteract other compensatory mechanisms. An example is the increase in norepinephrine, one of the successors to dopamine, which inhibit reuptake of the glutamate receptors, in charge of memory and cognition. The net effect is an increase in reward pathway sensitivity, the opposite of other addictive drugs such as cocaine and heroin, which reduce reward pathway sensitivity. This neuronal brain alteration can persist for months after administration ceases.

A study found that nicotine exposure in adolescent mice retards the growth of the dopamine system, thus increasing the risk of substance abuse during adolescence.

Some have been able to re-start their natural dopamine production and bypass months or years of depression caused by nicotine withdrawal by using a combination of 2 over-the-counter supplements: 5-HTP (5-Hydroxytryptophan also known as oxitriptan) and L-Tyrosine (para-hydroxyphenylalanine). Studies of the combination have been conducted only on general depression and no one has yet measured the effects specifically on nicotine withdrawal-related depression. However, anecdotal evidence suggests that the combination can be effective. In addition to being a natural and low-cost alternative to prescription anti-depressants, this protocol also has the benefit of being short-term in that the treatment is only necessary for a few months after nicotine abatement. Certain side effects, especially negative drug interactions, have been found with 5-HTP, so this treatment should not be undertaken in combination with any prescription medication or without specific approval from a doctor.