Dopamine is an active chemical substance produced by human brain cells and a hormone that is secreted by the adrenal glands. Dopamine is naturally released during processes from which a person derives pleasure, which is why the brain uses this hormone to evaluate and reinforce important actions for further life.

Dopamine receptor agonists – substances that stimulate the work of dopamine receptors and increase hormone production – are used to facilitate certain conditions such as Parkinson’s disease. Scientists conduct many studies aimed at discovering the role of dopamine in other processes such as addiction formation, cancer treatment, and even smoking cessation.

Stopping smoking

Stopping smoking can be influenced by genes. The presence of a specific variant of the Taq1A gene in human DNA, called Taq1A A2/A2, may directly affect a person’s ability to quit smoking. An international group of scientists led by Ma Jün-lun from the Medical Faculty of Jiangxi University in China published their study on Tuesday evening in the Translational Psychiatry and Nature journals.

The Taq1A A2/A2 gene codes for the function of dopamine receptors, thereby altering their level of activity. An excess of dopamine in a person’s brain subsequently contributes to the formation of nicotine addiction – the brain begins to “perceive” smoking as pleasurable, and thus it becomes an activity that needs to be repeated.

The researchers analyzed the results of 22 studies, which included data on 11,075 individuals, of which 9,487 were of European descent. The authors of the study claim that they have discovered a certain correlation:

People of European descent who had a specific variant of the Taq1A gene in their DNA (Taq1A A2/A2) were much more likely to successfully manage nicotine addiction and refuse smoking than those who had Taq1A A1/A1 or Taq1A A1/A2 genes.

The researchers emphasize that their work requires further verification, and the use of the conclusions obtained in medical practice is premature at this point.

Gaming addiction – a side effect of treatment

Another group of researchers found that doctors have overestimated the effectiveness of dopamine receptor agonists, which have been used to treat Parkinson’s disease and mental disorders.

Agonist drugs affect dopamine receptors, increasing their activity. Excessive amounts of hormones have caused various mental disorders and addictions.

Over the course of ten years, 1580 cases of addiction as a side effect of medication were reported in 21 countries around the world. These cases included 628 cases of gambling addiction, 465 cases of hypersexuality, and 202 cases of compulsive buying. Of the 1580 diagnosed cases, 710 were caused by dopamine receptor agonists, and the remaining 870 were caused by all other types of hormone-altering medications. More information about the research can be found in the JAMA Internal Medicine journal.

Dopamine against cancer

Researchers at Ohio State University led by Sudjit Basu, however, propose the use of dopamine as a drug for cancer treatment. The relevant article was published in the International Journal of Cancer.

Scientists claim that the use of dopamine significantly slows down the growth of blood vessels in malignant tumors, which is one of the key factors in its growth because blood vessels provide nourishment to cancer.

In addition, researchers claim that the use of dopamine reduces the negative impact of 5-fluorouracil (an anti-cancer drug used in chemotherapy) on the patient’s blood count.

If you don’t have enough dopamine, your eyesight can worsen

This summer, scientists announced that they had discovered the real cause of myopia in today’s teenagers. An article about the work of researchers was published in the journal Nature.

In recent decades, myopia has become an epidemic: the number of people with myopia in Europe and the USA has more than doubled over the past century, and the situation is even worse in Asian countries. If 60 years ago only 10-20% of Chinese people suffered from myopia, now 90% of them do. In Seoul, 95.6% of 19-year-old young people have myopia.

For many years, doctors have studied the causes of myopia, which is caused by the elongation of the eye and the focusing of the image in front of the retina, not on it. During the research, it was found that genetics or the habit of current people to spend a lot of time reading and in front of electronic devices are not decisive causes of the disease: the authors of the research claim that myopia is caused by a lack of daylight.

Modern people spend much less time outdoors, and this is precisely what causes myopia to develop, because under the influence of bright daylight, the retina of the eye produces dopamine, and its lack causes elongation of the eye.

Doctors estimated that to maintain good eyesight, a person must spend at least three hours a day in light with an intensity of 10,000 lux (the brightness of sunlight), while the highest indoor lighting usually does not exceed 5,000 lux.