Understanding the Causes and Effects of Drug Addiction and How Treatment Can Help

Biological factors are widely recognized as significant contributors to the development of addiction and nature of these biological underpinnings varies widely. According to the American Society of Addiction Medicine (ASAM) , for example, “Genetic factors account for about half of the likelihood that an individual will develop addiction.” However, there is no single gene responsible for addiction; rather, experts believe that the genetic component of addiction involves “multiple genes that control various aspects of the biological response to drugs or physiological predisposition to become an abuser.” In fact, genetic variation appears to increase or decrease addiction risk in multiple and potentially overlapping ways.

In addition to specific addiction-related genes, there are a number of other biological phenomena related to addiction risk. Researchers have found that certain structural brain abnormalities are associated with elevated risk, including “a decrease in the density of white matter in the front of the brain, which suggests a decrease in self-control, and an increase in gray matter in the middle regions of the brain, which suggests an increased ability to form habits.” Studies also reveal that variations neurotransmitter activity and reward circuitry can have a significant impact on vulnerability to addiction, as can cognitive impairment and affective distortions.

The presence of a mental health disorder is known to be one of the primary risk factors for developing drug or alcohol addiction. As the Centre for Addiction and Mental Health notes, “People with a mental illness are twice as likely to have a substance use problem compared to the general population. Similarly, people with substance use problems are up to 3 times more likely to have a mental illness.” Indeed, it is estimated that at least 20% of people with a mental health disorder also have a substance use disorder and some disorders elevate the risk even higher; approximately half of people with schizophrenia or bipolar disorder will experience a substance use disorder in their lifetime.

The reasons for this overlap are not fully understood, but researchers believe that it may be partially explained due to shared genetic vulnerabilities and the fact that mental illness and addiction involve similar areas of the brain, including potential dysfunction in dopamine pathways and other neurotransmitter activity. Additionally, people struggling with mental health disorders may seek to alleviate their emotional suffering or address their symptoms through the use of drugs or alcohol and they may be particularly susceptible to the pleasurable effects of these substances. The National Institute on Drug Abuse explains that changes in the brain associated with mental illness “may increase the vulnerability to abusing substances by enhancing their positive effects, reducing awareness of their negative effects, or alleviating the unpleasant effects associated with the mental disorder or the medication used to treat it.”

Environmental and experiential factors can affect the development of addiction in a number of critical ways. Researchers have found that ”family atmosphere, strength of family ties, sense of family happiness, structure of authority in the family, and alcoholism” can all have a significant impact on risk of addiction. More specifically, people who grow up in hostile family environments, families with weak ties, and families in which alcohol or drug abuse was present are more likely to develop addiction. Other environmental and experiential factors linked to addiction include:

• Early exposure to drugs, especially at critical developmental stages
• Childhood abuse, including physical, emotional, and sexual abuse
• Trauma, including traumas experienced in adulthood
• Lack of healthy social supports and activities
• Stress

One of the most significant risk factors for the development of addiction is exposure to a social environment in which drugs are available and acceptable. It is known that peer attitudes regarding drugs is a critical predictor of substance abuse amongst adolescents and studies have found that peers are “the most important influence with regard to initiation.” However, the impact of peer attitudes extends beyond adolescence. People whose social or professional environments encourage substance use are more likely to both use drugs and alcohol and develop substance use disorders.

It is important to note that environmental and experiential factors can interact with biological and psychological factors to elevate risk or provide a protective effect. For example, a healthy, stable, and supportive family environment can make it less likely that someone with a genetic predisposition for alcohol abuse will abuse alcohol. On the other hand, someone with the same genetic predisposition who grew up in a conflict-ridden household where they witnessed substance abuse is more likely to develop an addiction.

Within the modern medical community, drug addiction is understood to be a chronic, relapsing brain disorder. This disorder is not something people are born with. Rather, drug use itself create the structural and functional changes in the brain that characterize the disorder. With prolonged drug use, the brain comes to adapt to the presence of the drug, modifying neurotransmitter activity and reconfiguring brain regions involved in learning, memory, judgment, and decision-making. These changes mean that your loved one needs a continuous supply of drugs to maintain equilibrium while simultaneously conditioning the brain for compulsive drug-seeking, diminished impulse control, and compromised cognitive function. In other words, while environmental, psychological, environmental, and experiential factors can set the stage for addiction to take hold, addiction itself is a distinct neurological phenomenon that, if untreated, is self-perpetuating.