Tag Archives: depression

Neural Pathway Linked to Addiction and Depression

New research conducted by a team at the University of Maryland School of Medicine in Baltimore has identified a neural pathway that is linked to addiction and depression. Their findings, which were recently published in the journal Nature, found an increased intensity of signals passing between the hippocampus and the nucleus accumbens.

Pleasure and Reward System Governed by the Brain

The pleasure and reward system is one of the most important systems that the brain regulates in humans. It gives us the “nudge” we need to eat, drink and be sexually active. All these activities are needed to ensure the continued survival of our species.

The way the reward system operates is also an important factor in many types of addictive behavior.

Professor Scott Thompson, Ph.D., the leader of the research team, stated that the two parts of the brain (the hippocampus and the nucleus accumbens) are known to be important in processing rewarding experiences for humans. He went on to say that the communication between the two is stronger in a case of addiction, although the underlying mechanisms were unknown to the team.

Team Tests Depression Hypothesis

The research team tested a new hypothesis: whether the same signals became weaker in people living with depression. Since one symptom of depression is anhedonia (a loss of pleasure in usually pleasurable activities), the researchers wanted to discover whether weakening signals in the neural pathways could be the underlying cause of depressed patients.

Using mice, the team focused on brain circuitry that plays an important role in goal-oriented behavior. They wanted to see if they could change the animals’ activity. They added light-sensitive proteins into the neurons forming the brain’s circuitry. Once this step was completed, the researchers hoped to control the signals by blocking or boosting the levels between the hippocampus and the nucleus.

The researchers created a false reward memory in the mice that received the light-sensitive protein by exposing them to light during a four second period. This meant the mice learned to associate pleasure with the location where they felt light exposure.

After a day, the researchers took the mice back to the place where they had received the false memory of associating pleasure with light and exposed them to light again. The goal was to shut down the signal between the hippocampus and the nucleus accumbens this time, however.

They confirmed this pathway is critical to the way the brain is wired for reward association. Once the pathway is shut down, the mice stopped liking the location where they originally received the reward memory.

Next, the researchers looked at depression. They tried to boost brain activity in depressed mice but this part of the experiment wasn’t successful. The researchers had to administer antidepressants to the mice before they could imprint any artificial reward memories in the brain of depressed mice.

Dr. E. Albert Reece, the dean of the University of Maryland School of Medicine, said these are exciting results that will bring us closer to understanding what’s happening in the brains of clinically depressed patients.

Income Bracket Can be Affected by Substance Abuse and Depression

Many people set the course of their lives when they are in their early twenties. That is the time when they decide to complete college, gain valuable knowledge in internships and first real-world jobs, start learning the importance of networking and making good connections. Hopefully somewhere in there they start earning a decent living and begin saving money as well. However, a new study shows that those who suffer from an addiction and mental health issues during their early twenties have a much more difficult time securing their future and are more likely to end up in lower income brackets by the time they are middle-aged.

“In the United States, co-occurring substance use and mental health disorders impact around nine million people each year, yet these disorders are still generally treated separately. How we treat these dual disorders can have a significant impact on people’s ability to earn a livelihood,” explained Dr. Dagher, the author on the study that was conducted at the University of Maryland School of Public Health.

This information is important because many people who are suffering from an addiction to drugs also display symptoms of depression and other behavioral disorders. In a society where the economy is constantly in question, and in an age where employers are having a harder time finding qualified employees, it is necessary to isolate any potential problems in the future workforce. Additionally, for those who are struggling with substance abuse it is important to be aware of yet another reason to handle their addiction.

The authors of the study, which appeared in the journal Psychiatry Research, state that those who address their co-occurring issues of addiction and depression generally do not experience the same difficulty regarding income bracket as those who never seek help for their problems. The researchers found that there were more periods of unemployment as well as a greater likelihood of lower income jobs.

The authors of the study hope that this information will push policymakers to allot more funds for treatment so as to stop potential socioeconomic problems in the future.