08/19/2011 08:23 am ET Updated Oct 19, 2011

Is it an Addiction? 7 Telltale Signs

Two friends with similar backgrounds both drink heavily while in their 20s, but one eventually cuts down and moves on, while the other's drinking progresses into full-blown alcoholism. While science is still unable to distinguish between these two individuals before they start drinking, recent advances in addiction research show promise in explaining why some people can engage in potentially addictive activities in moderation while others cannot.

Most of us can relate to the experience of wanting to do some pleasurable thing we know is bad for us -- mentally struggling for a few moments over what to do, and then giving into the urge. From a neurological perspective, this is our cortex (the part of our brain that makes complex decisions) losing an argument with our reward system (a more primitive set of brain structures). Over hundreds of thousands of years, evolution has fine-tuned the connection between these systems to create the right balance between drive and restraint. Scientists believe that addiction may be the result of the connections between these areas of our brain becoming imbalanced.

Just as we differ from one another in physical characteristics, we also differ in neurological ones. For example, John and David both have eyes, but John's are brown and David's are blue. Similarly, both John and David have short-term memory, but John may recall information more rapidly than David. When neurological characteristics such as these are associated with a disorder and are determined by our genes, neurobiologists call them "endophenotypes."

Predisposition to addiction is likely the result of several interacting endophenotypes. For example, difficulty controlling one's impulses may be an endophenotype that increases the likelihood of someone becoming addicted. In these individuals, the connections between the cortex and reward system may be weighted in such a way that drive is favored over restraint in situations where it would be the opposite for others.

Addiction is also the result of environmental exposure; no one becomes an alcoholic without exposure to alcohol. In this respect, addiction is a disorder of the modern world. It has resulted from access to substances and technologies that engage our reward system unlike anything that existed when our brains first evolved. Even the oldest drugs, such as alcohol, opium and marijuana, were not discovered until long after the arrival of biologically modern humans. So, when our brains are exposed to modern substances, like crack cocaine or the instant and nearly infinite sexual imagery available on the Internet, the power of our reward system may grow out of control.

Other environmental factors associated with the development of addiction include a history of trauma, childhood adversity and stress. It is perhaps not surprising that these factors are also associated with the development of depressive and anxiety disorders, which themselves are linked to an increased risk of addiction. For those suffering from longstanding emotional pain, engaging in an addictive behavior may be experienced more as a relief from misery than getting high. In such cases, it's not hard to understand why someone might continue using even in the face of significant consequences.

While an advanced addiction is easy to identify, less severe forms may appear differently in different people, and even addiction specialists cannot predict which individuals with early signs of a problem will go on to develop an addictive disorder. Nonetheless, the following seven signs are core features of the addictive process and, if present, suggest an addiction may be at play.

Do you have a question about anxiety or addiction for Dr. Schiffman? Email them to: jschiffman@ANXIETY.ORG. Dr. Schiffman will answer as many questions as possible in upcoming posts.

7 Signs Of Addiction