The cause of addiction has been a mystery since time immemorial. Even certified and experienced researchers and medical practitioners fail to understand the driving force behind this dependence. Researches are being conducted to discover and understand people’s incessant craving for certain things, their failure in gaining control over the use and their unrelenting involvement in it to the point of it turning lethal.
Addiction in adolescents
Though scientists have been unable to comprehend the trigger behind enslavement to drugs, they agree to the fact that young adults are at a heightened risk of being dependent on drugs, despite having no evidence to assert their views.
Two recent studies, conducted on mice and humans, have revealed the possible reasons for teenagers’ increased susceptibility to addiction and the biological basis that adds to their chance of dependence to certain things.
One study, titled “Translational control by eIF2α phosphorylation regulates vulnerability to the synaptic and behavioral effects of cocaine,” revealed that a decrease in the phosphorylation of the translation initiation factor eIF2α (p-eIF2α) protein explains adolescents’ susceptibility to the synaptic and behavioral effects of cocaine.
In the study, published in the journal eLife in March 2016, the scientists observed that in young mice, a low dose of cocaine reduced p-eIF2α in the ventral tegmental area (VTA), potentiated synaptic inputs to VTA dopaminergic neurons and induced drug-reinforced behavior.
Scientists also observed that adult mice with reduced p-eIF2α-mediated translational control had more chance to be affected by cocaine-induced synaptic potentiation and behavior and those with the increased amount of protein showed strong resistance to the impact of cocaine.
The same effect was noticed for other forms of addictive substances like alcohol, methamphetamine and nicotine, suggesting that protein eIF2α is the common target of various substances of abuse. The researchers said, “Reduced eIF2α activity accounts for why adolescents are particularly vulnerable to the synaptic and behavioral effects of cocaine.”
In another study, titled “Translational control of nicotine-evoked synaptic potentiation in mice and neuronal responses in human smokers by eIF2α,” scientists observed that nicotine heightens the probability of excitatory synaptic transmission in ventral tegmental area dopaminergic neurons in young mice compared with their adult counterparts. The study was published in the journal eLife in March 2016.
Nicotine, the main addictive ingredient, leads people to smoke more. During the study, the researchers also observed that adult mice with decrease in p-eIF2α-mediated translation (whether due to genetic variations or the effect of drugs) are at an increased risk of falling to the synaptic effects of nicotine, like the young mice.
When scientists examined the impact of allelic variability of the Eif2s1 gene (encoding eIF2α) on reward-related neuronal responses in human smokers, they found that a single nucleotide polymorphism in the Eif2s1 gene modulates mesolimbic neuronal reward responses in human smokers.
The findings pointed to the possibility of protein p-eIF2α controlling synaptic actions of nicotine in both mice and humans giving way to the possible conclusion that diminishing levels of p-eIF2α intensify vulnerability to nicotine and other substances of abuse during the adolescent phase.
Significance of the study
Though the first study could not explain how cocaine abuse reduces p-eIF2α activity, it paved the way for further researches to be conducted about probable causes of drug dependence, along with new hopes for further treatment.
The second study raises an important question – whether changes in levels of eIF2α can give way to uncontrollable urge to use nicotine.
Though further researches are needed to further understand the cause of addiction, observations of both the studies coerce scientists to study and understand if targeting parts of the eIF2α pathway can lead to important breakthroughs in the treatment of addiction.
Addiction to any substance can only harm in the long run. But addiction is treatable even though the road to recovery is not easy. If you or your loved one is trying to overcome an addiction, call the California Drug Abuse Helpline. The experts available at the 24/7 helpline number 855-980-1946 or via online chat can guide you to the best treatment in your vicinity.