It has long been known that trauma at a young age can make a person vulnerable to a number of mental illnesses as well as addiction. Recently, however, researchers have made advances into understanding exactly why this is and specifically how trauma is linked to depression and addiction. Traumatic events during childhood actually change the brain and its neural pathways, which leads to addiction and depression. The researchers from the University of Texas who made these findings started with a group of 32 teenagers. Of that group, 19 had been maltreated during childhood, but were not diagnosed with a psychiatric disorder at the time of the study. The maltreatment was defined by the study organizers as either abuse or neglect that was significant and that lasted for a minimum of six months. It is important to note that neglect counts as trauma, although it is often overlooked as such. Some of the 19 participants experienced trauma as a single event, such as having a life-threatening illness or losing a parent while under the age of ten. The remaining teenagers acted as a control group and had experienced no major trauma or maltreatment during childhood. The teenagers in the study checked in with researchers every six months for about three and a half years. Nearly half of the children who had experienced trauma developed depression, an addiction, or both during the course of the study. Five of the teens had major depression, four had substance abuse disorders, and two had both depression and an addiction. One of the control teens had developed a substance abuse problem during this time. The comparison between the two groups showed that the rate of developing depression or addiction in the maltreated teens was three times higher than in the control group of teens. The above findings are not exactly surprising. That maltreatment, neglect, and trauma lead to depression and substance abuse makes sense. What the researchers did to continue the study led to new discoveries about trauma and the brain. All of the teens had their brains imaged at the beginning of the research, before any of them had developed psychiatric troubles or substance abuse. The imaging showed the white matter in the brain, which is the tissue that connects different regions. The differences in the brains of the maltreated teens and those in the control group were significant, even before addiction and depression developed. The teens experiencing trauma had problems with connections in the white matter. Specifically, connectivity was disrupted in the superior longitudinal fasciculus (SLF) region, which is responsible for language processing and planning. The right cingulum-hippocampus projection (CGH-R) was also affected in the traumatized teens. This part of the brain connects regions responsible for emotional processing with abstract thought. The connection should allow a person to make appropriate responses to emotional stresses. Furthermore, there were differences in the brains of the teens who developed depression and those who became addicted to a substance. The teens that ended up with depression had poor connections in the SLF region, while those with drug addictions had more poor connections in the CGH-R. The differences led researchers to speculate on the causes of both depression and addiction. The failed connections in the SLF area suggest that depression is linked to the processing of language, while changes in the CGH-R may mean that addiction is connected to poor emotional responses and an inability to regulate those responses. Understanding the areas of the brain involved in addiction and depression is very promising to the future of treatment. Although the study was small, involving only 32 teenagers, the results are intriguing and show that trauma physically changes the brain. Furthermore, the connection between those physical changes and the resulting emotional, psychiatric, and addictive behaviors and disorders is a new distinction. Other studies have shown changes in white matter in maltreated children and there were some differences between that study and this new research. This just means that more research is needed and larger groups of children who have unfortunately experienced trauma need to be studied. Even though this group was small, it adds important information to the body of research into trauma, addiction, and mental illness and offers very promising avenues for future study and for potentially effective treatments.