Category Archives: Depression

Depression

How the brain manages stress suggests new model of depression

From Medical News Today

Discovery of new molecular and behavioral connections may provide a foundation for the development of new treatments to combat some forms of depression

The brain’s ability to effectively deal with stress or to lack that ability and be more susceptible to depression, depends on a single protein type in each person’s brain, according to a study conducted at the Icahn School of Medicine at Mount Sinai and published n the journal Nature.

The Mount Sinai study findings challenge the current thinking about depression and the drugs currently used to treat the disorder.

“Our findings are distinct from serotonin and other neurotransmitters previously implicated in depression or resilience against it,” says the study’s lead investigator, Eric J. Nestler, MD, PhD, Nash Family Professor, Chair of the Department of Neuroscience and Director of the Friedman Brain Institute at the Icahn School of Medicine at Mount Sinai. “These data provide a new pathway to find novel and potentially more effective antidepressants.”

The protein involved in this new model of depression is beta-catenin (B-catenin), which is expressed throughout the brain and is known to have many biological roles. Using mouse models exposed to chronic social stress, Mount Sinai investigators discovered that it is the activity of the protein in the D2 neurons, a specific set of nerve cells (neurons) in the nucleus accumbens (NAc), the brain’s reward and motivation center, which drives resiliency.

Specifically, the research team found that animals whose brains activated B-catenin were protected against stress, while those with inactive B-catenin developed signs of depression in their behavior. The study also showed suppression of this protein in brain tissue of depressed patients examined post mortem.

“Our human data are notable in that we show decreased activation of B-catenin in depressed humans, regardless of whether these individuals were on or off antidepressants at the time of death,” says the study’s co-lead investigator, Caroline Dias, an MD-PhD student at the Icahn School of Medicine at Mount Sinai. “This implies that the antidepressants were not adequately targeting this brain system.”

In the study, researchers blocked B-catenin in the D2 brain cells in mice that had previously shown resilience to depression and found the animals became susceptible to stress. Conversely, activating B-catenin in stress mice bolstered their resilience to stress.

Nearly all nerve cells in the NAc brain region are called medium spiny neurons. These cells are divided into two types based on how they detect the neurotransmitter dopamine, which is important in regulating reward and motivation. One type of neuron detects dopamine with D1 receptors and the other with D2 receptors. The Mount Sinai data specifically implicate the D2 neurons in mediating deficits in reward and motivation that contribute to depression or enhancements that mediate resilience.

Examining the genes regulated by B-catenin, the team then traced the pathway that was engaged when B-catenin was activated in the D2 neurons and discovered a novel connection between the protein and Dicer1, an enzyme important in making microRNAs, small molecules which control gene expression.

“While we have identified some of the genes that are targeted, future studies will be key to see how these genes affect depression. Presumably, they are important in mediating the pro-resilient effects of the B-catenin-Dicer cascade,” says Dr. Dias.

While the molecular underpinnings of depression have remained elusive despite decades of research, the new Mount Sinai study breaks new ground in understanding depression in three important ways. It is the first report that B-catenin is deficient in nucleus accumbens in human depression and mouse depression models; it is the first study to show that higher activity of B-catenin drives resilience and the first report demonstrating a strong connection between B-catenin and control of microRNA synthesis.

The findings also suggest that future therapy for depression could be aimed at bolstering resilience against stress.

“While most prior efforts in antidepressant drug discovery have focused on ways to undo the bad effects of stress, our findings provide a pathway to generate novel antidepressants that instead activate mechanisms of natural resilience,” says Dr. Nestler.

Adapted by MNT from original media release

 

Depression, Lifestyle, Psychology

The Psychological Comforts of Storytelling

The Atlantic:

When an English archaeologist named George Smith was 31 years old, he became enchanted with an ancient tablet in the British Museum. Years earlier, in 1845, when Smith was only a five-year-old boy, Austen Henry Layard, Henry Rawlinson, and Hormuzd Rassam began excavations across what is now Syria and Iraq. In the subsequent years they discovered thousands of stone fragments, which they later discovered made up 12 ancient tablets. But even after the tablet fragments had been pieced together, little had been translated. The 3,000-year-old tablets remained nearly as mysterious as when they had been buried in the ruins of Mesopotamian palaces.

An alphabet, not a language, cuneiform is incredibly difficult to translate, especially when it is on tablets that have been hidden in Middle Eastern sands for three millennia. The script is shaped triangularly (cuneus means “wedge” in Latin) and the alphabet consists of more than 100 letters. It is used to write in Sumerian, Akkadian, Urartian, or Hittite, depending on where, when, and by whom it was written. It is also an alphabet void of vowels, punctuation, and spaces between words.

Even so, Smith decided he would be the man to crack the code. Propelled by his interests in Assyriology and biblical archaeology, Smith, who was employed as a classifier by the British Museum, taught himself Sumerian and literary Akkadian.

Read the whole story: The Atlantic

Depression, Parenting, Psychology, PTSD

Childhood psychological abuse as harmful as sexual or physical abuse

From Medical News Today 10/10/2014

Children who are emotionally abused and neglected face similar and sometimes worse mental health problems as children who are physically or sexually abused, yet psychological abuse is rarely addressed in prevention programs or in treating victims, according to a new study published by the American Psychological Association.

“Given the prevalence of childhood psychological abuse and the severity of harm to young victims, it should be at the forefront of mental health and social service training,” said study lead author Joseph Spinazzola, PhD, of The Trauma Center at Justice Resource Institute, Brookline, Massachusetts. The article appears in a special online issue of the APA journal Psychological Trauma: Theory, Research, Practice, and Policy.

Researchers used the National Child Traumatic Stress Network Core Data Set to analyze data from 5,616 youths with lifetime histories of one or more of three types of abuse: psychological maltreatment (emotional abuse or emotional neglect), physical abuse and sexual abuse. The majority (62 percent) had a history of psychological maltreatment, and nearly a quarter (24 percent) of all the cases were exclusively psychological maltreatment, which the study defined as care-giver inflicted bullying, terrorizing, coercive control, severe insults, debasement, threats, overwhelming demands, shunning and/or isolation.

Children who had been psychologically abused suffered from anxiety,depression low self-esteem, symptoms of post-traumatic and suicidality at the same rate and, in some cases, at a greater rate than children who were physically or sexually abused. Among the three types of abuse, psychological maltreatment was most strongly associated with depression, general anxiety disorder,social anxiety disorder>, attachment problems and substance abuse. Psychological maltreatment that occurred alongside physical or sexual abuse was associated with significantly more severe and far-ranging negative outcomes than when children were sexually and physically abused and not psychologically abused, the study found. Moreover, sexual and physical abuse had to occur at the same time to have the same effect as psychological abuse alone on behavioral issues at school, attachment problems and self-injurious behaviors, the research found.

“Child protective service case workers may have a harder time recognizing and substantiating emotional neglect and abuse because there are no physical wounds,” said Spinazzola. “Also, psychological abuse isn’t considered a serious social taboo like physical and sexual child abuse. We need public awareness initiatives to help people understand just how harmful psychological maltreatment is for children and adolescents.”

Nearly 3 million U.S. children experience some form of maltreatment annually, predominantly by a parent, family member or other adult caregiver, according to the U.S. Children’s Bureau. The American Academy of Pediatrics in 2012 identified psychological maltreatment as “the most challenging and prevalent form of child abuse and neglect.”

For the current study, the sample was 42 percent boys and was 38 percent white; 21 percent African-American; 30 percent Hispanic; 7 percent other; and 4 percent unknown. The data were collected between 2004 and 2010 with the average age of the children at the beginning of the collection between 10 and 12 years. Clinicians interviewed the children, who also answered questionnaires to determine behavioral health symptoms and the traumatic events they had experienced. In addition, caregivers responded to a questionnaire with 113 items pertaining to the child’s behavior. Various sources, including clinicians’ reports, provided each child’s trauma history involving psychological maltreatment, physical abuse or sexual abuse.