The Impact of Child Sexual Abuse on Addiction: An Analysis of Trauma Processing

Molecular and genetic substrates linking stress and addiction

Drug addiction is one of the top three health concerns in the United States in terms of economic and health care costs. Despite this, there are very few effective treatment options available. Therefore, understanding the causes and molecular mechanisms underlying the transition from casual drug use to compulsive drug addiction could aid in the development of treatment options. Studies in humans and animal models indicate that stress can lead to both vulnerability to develop addiction, and increased drug taking and relapse in addicted individuals. Exposure to stress or drugs of abuse results in long-term adaptations in the brain that are likely to involve persistent alterations in gene expression or activation of transcription factors, such as the cAMP Response Element Binding (CREB) protein. The signaling pathways controlled by CREB have been strongly implicated in drug addiction and stress. Many potential CREB target genes have been identified based on the presence of a CRE element in promoter DNA sequences. These include, but are not limited to CRF, BDNF, and dynorphin. These genes have been associated with initiation or reinstatement of drug reward and are altered in one direction or the other following stress. While many reviews have examined the interactions between stress and addiction, the goal of this review was to focus on specific molecules that play key roles in both stress and addiction and are therefore posed to mediate the interaction between the two. Focus on these molecules could provide us with new targets for pharmacological treatments for addiction.

The impact of stress on addiction

This article will review data obtained from both clinical and preclinical investigations demonstrating that exposure to stress has a significant impact on drug addiction. The preclinical literature suggests that stress increases reward associated with psychomotor stimulants, possibly through a process similar to sensitization. While it is not conclusive that a similar process occurs in humans, a growing clinical literature indicates that there is a link between substance abuse and stress. One explanation for the high concordance between stress-related disorders and drug addiction is the self-medication hypothesis, which suggests that a dually diagnosed person often uses the abused substance to cope with tension associated with life stressors or to relieve symptoms of anxiety and depression resulting from a traumatic event. However, another characteristic of self-administration is that drug delivery and its subsequent effects on the hypothalamo-pituitary-adrenal (HPA) axis are under the direct control of the individual. This controlled activation of the HPA axis may result in the production of an internal state of arousal or stimulation that is actually sought by the individual (i.e., the sensation-seeking hypothesis). During abstinence, exposure to stressors or drug-associated cues can stimulate the HPA axis to remind the individual about the effects of the abused substance, thus producing craving and promoting relapse. Continued investigations into how stress and the subsequent activation of the HPA axis impact addiction will result in the identification of more effective and efficient treatment for substance abuse in humans. Stress reduction, either alone or in combination with pharmacotherapies targeting the HPA axis may prove beneficial in reducing cravings and promoting abstinence in individuals seeking treatment for addiction.

Drug treatment outcomes: investigating the long-term effects of sexual and physical abuse histories

Individuals in drug treatment, particularly women, generally report high levels of past sexual and physical abuse. Although histories of sexual and physical abuse are associated with greater prevalence and severity of depression, anxiety, phobias, and interpersonal difficulties for individuals seeking substance-related treatment, several recent studies failed to show that prior sexual or physical abuse compromised short-term drug treatment outcomes. This study examined the possible effects of sexual and physical abuse on a wide array of behavioral domains over a two-year posttreatment period. The findings indicate few differences between those with and without past histories of such abuse in terms of drug use, drug treatment and 12-Step program participation, criminality, income sources, intimate relationships, family functioning, and psychiatric symptoms. There are specific exceptions, but they apply only to men. Overall, the findings indicate that the impact of sexual and physical abuse histories on relatively long-term treatment outcomes is minimal. Addressing the sexual and physical abuse histories of those seeking treatment for drug abuse may be justified on humanistic grounds, but it will not significantly improve the long-term effectiveness of drug treatment, nor will it substantially enhance the lives of those with histories of abuse.