More importantly, greater reductions in discounting predict a greater likelihood of protracted abstinence among cocaine users and smokers . Thus, if a causative link between D2 /D3 receptor availability and temporal discounting is established, it may lead to the development of novel D2 /D3 -targeted interventions which could be used to more effectively treat a variety of disorders. In conclusion, the results of this study indicate that low D2 / D3 receptor availability is associated with steep temporal discounting. This link may explain why some individuals choose to continue using drugs despite knowledge of their future negative consequences, and could help to guide strategies for treating substance abuse and other psychiatric disorders.Dissociation, which involves detachment from one’s physical and emotional experiences and is associated with symptoms such as depersonalization , de-realization , and other amnesic/ fugue states, is generally understood to be a psychological defense in the face of current and past trauma . There is some evidence that dissociation is linked to genetic factors within the context of early trauma exposure . Furthermore, childhood physical and sexual abuse are associated with elevated dissociative symptoms in homeless veteran populations and younger populations including homeless teens . In fact, child abuse appears to be one of the more robust predictors of dissociation in adulthood . Adult survivors of childhood abuse are more likely to experience dissociative symptoms than individuals who are not survivors of childhood abuse in both clinical and non-clinical populations . Several studies across a variety of cultures and populations have demonstrated that survivors of childhood sexual abuse are more likely to develop dissociative symptoms than those who have experienced other types of childhood abuse . Furthermore,4×8 grow table with wheels numerous studies have noted that individuals who are victims of childhood abuse are more likely to become victims of violence in adulthood .
Given that survivors of childhood abuse are at increased risk of exposure to other traumas across the lifespan , Chu has suggested that dissociation experienced after childhood sexual abuse may mediate the influence of childhood sexual abuse on future increased risk for adult violent victimization . Although the mechanisms behind violent victimization remain varied and unclear, it is suggested that elevated dissociative symptoms may be linked to a suppressed anticipatory anxiety response, which increases the likelihood that individuals with a history of childhood abuse may put themselves in potentially dangerous situations . One study that investigated the relationship between post traumatic stress disorder and dissociative symptoms in a sample of college women found no evidence that dissociative symptoms mediated violent victimization . However, other studies have found evidence that dissociation may be associated with an increased likelihood of violent physical and sexual victimization in both clinical and non-clinical adult samples . Whether differences in results are due to different populations, different research questions, or other factors is unclear. Few investigations have directly assessed the relationship between violence and dissociation among homeless and unstably housed women and none have attempted to establish a causal or directional relationship between child abuse, dissociation, and recent adult violent victimization. The dearth of relevant research leaves a notable gap in our understanding of how childhood abuse and dissociation may lead to violent victimization, especially for particularly vulnerable populations such as homeless and unstably housed women. Our prior work among homeless and unstably housed women found extremely high levels of childhood abuse , as well as recent violent victimization . Within the same sample of homeless and unstably housed women, we have also shown that recent sexual violence is strongly associated with other subsequent negative outcomes such as the increased likelihood of stimulant use initiation .
The disproportionately common occurrence of violence against unstably housed women, and the strong influence of violence on a variety of other mental health conditions, makes these critical issues to address in this population . The current study aimed to increase our understanding of the relationships between childhood abuse, dissociation, and violent victimization in the same population of homeless and unstably housed adult women. Using the Chu model, which hypothesizes that dissociation resulting from childhood sexual abuse increases risk for future sexual violence, as a frame we asked women to report any violent victimization six months prior to an initial assessment and in the intervening six months prior to a followup assessment. Our hypothesis was that after accounting for psychiatric comorbidity and other sociocultural factors unique to homeless persons, childhood physical abuse, childhood sexual abuse and dissociation would still predict both physical and sexual violence between the initial assessment and the six-month follow-up interview. We also hypothesized that dissociation would mediate the influence of childhood physical abuse and sexual abuse on physical and sexual violence. This prospective analysis was conducted within the Shelter, Health, and Drug Outcomes among Women Study, a community-based observational cohort study designed to understand risks for poor health and victimization among homeless and unstably housed women. As we have described elsewhere , a mobile outreach team used systematic probability sampling to recruit a cohort reflective of the larger San Francisco homeless and unstably housed female population. Details regarding recruitment have been previously published . In brief, study participants were recruited from homeless shelters, free meal programs and low-income single room occupancy hotels. Eligibility was limited to biological females who were ≥ 18 years old and who had a history of housing instability .
Three-hundred homelessness or unstably housed women were enrolled in the cohort between 2008 and 2010, and followed every six months for a total of 7 time points ranging for a follow-up period of up to 3 years from recruitment date. In accordance with the aims of the parent study, HIV-positive women were over sampled so that they comprised 50% of the total cohort. The two-hundred-eighty-one participants who completed enrollment and 6- month follow-up interviews were included in the current study. Participants engaged in check-in visits with study staff between semi-annual study visits to update contact information and to ensure they remained engaged in study activities. All participants provided written informed consent. Upon enrollment, structured interviews were conducted in a private space at a community-based field site. Study questionnaires were interviewer administered. Socially sensitive questions, including those regarding violent victimization and drug use, were administered via an audio computer-assisted self-interviewing approach in which participants listened to questions through headphones and entered responses into a computer. All questionnaires and study procedures were pilot tested to ensure appropriateness for the target population. Reimbursement of $15 was given for each study interview. Study procedures were approved by the Institutional Review Board at the University of California, San Francisco.Measurement of violent victimization—Violent victimization was assessed using questions based on the Severity of Violence Against Women Scales ,grow tray stand which were tested previously in this cohort . Physical violence was defined as being hit, slapped, kicked, bitten, choked, shot, stabbed, or struck with an object. Sexual violence was defined as being forced to have sex of any kind. Physical and sexual violence occurring before age 18 were classified as childhood abuse. Adult violent victimization occurring in the preceding six months was assessed at the baseline and at the six-month follow-up. Dissociative Experiences Scale—Dissociation was assessed at the initial assessment using the Dissociative Experiences Scale , a 28 item scale where items related to dissociative experiences are rated on a 10-point scale. Items assess feelings of depersonalization they actually see themselves as if they were looking at another person. What percentage of the time do you have the experience?”, de-realization , and other dissociative experiences . The DES demonstrates excellent convergent and predictive validity in clinical and non-clinical populations . Higher scores on the DES indicate more self-reported dissociative experiences. The DES total score was computed as the sum of the 28 items. The DES does not provide a diagnosis of a dissociative disorder; however, for the purposes of this study it was defined as a score > 45 . Individual characteristics—Demographic, social, structural, and behavioral characteristics previously associated with health and violence among low-income women were used to describe the cohort.
Socioeconomic status was measured in terms of dichotomous indicators of low income , any unmet subsistence needs Gelberg, Gallagher, Andersen, & Koegel, , and homelessness . Substance use was measured by dichotomous indicators of any current cocaine use, any current methamphetamine use, any current opiate use, and current at-risk alcohol use . Mental health diagnoses were assessed at the initial assessment by the computerized Diagnostic Interview Schedule for the DSM-IV . Thirty-nine psychiatric diagnoses were assessed, including anxiety disorders , mood disorders , psychotic disorders , substance use disorders associated with alcohol, amphetamines, cocaine, opiates, and sedatives; abuse and dependence associated with hallucinogens, inhalants, marijuana, and phencyclidine; and dependence on other drugs, as well as somatization disorder, pain disorder, and dementia. All diagnoses assessed the presence versus absence of disorders. STATA Statistical Software: Release 13.1 was used to conduct all statistical analyses . Descriptive statistics were first generated for the variables described above. We then employed two separate hierarchical logistic regression models to understand the effects of four main characteristics on physical violence and sexual violence at the six-month follow up. The four main effects were childhood physical abuse, childhood sexual abuse, violent victimization during the six months prior to the initial assessment, and dissociation reported at the initial assessment. Specifically, physical violence in the six months prior to initial assessment was used to predict physical violence in the six months after initial assessment. Similarly, sexual violence in the six months prior to initial assessment was used to predict sexual violence in the six months after initial assessment. Main effects were estimated controlling for age, race, and, in accordance with our prior work regarding significant correlates of violence in this cohort , whether participants had recently experienced unmet subsistence needs. Ten theoretically and diagnostically relevant psychiatric diagnosis variables were created from the thirty-nine diagnoses assessed by the DIS. Related diagnoses were grouped into categories reflecting depressive, anxiety, bipolar, psychotic, alcohol, cannabis, amphetamine, cocaine, and opiate disorders, while uncommon diagnoses, such as dementia, were not included. We then used the Variance Inflation Factor to evaluate multicollinearity. Out of the ten psychiatric diagnoses, two highly dependent variables, any anxiety disorder; VIF = 13.02 and any bipolar disorder; VIF = 12.56 were dropped from the final list of variables that were included in the final analyses due to multicollinearity . Hierarchical modeling included four steps. The initial model included age in years, race, and dichotomous indicators of unmet subsistence needs, and violent victimization in the six months prior to initial assessment. The second step of the model included childhood physical abuse and childhood sexual abuse. The third step included mental health and substance use diagnoses. The final step included dissociation as measured by the DES total score. Interactions between dissociation and relevant covariates such as the presence of a substance use disorder were also tested because substance use is associated with symptoms similar to dissociation. Omnibus χ2 tests were used to assess model fit in predicting either physical violence or sexual violence at each step of analysis. McFadden’s R2 was used to assess proportion of model variance explained. Wald χ2 tests used to assess whether each subsequent model was incrementally more predictive of violent victimization from the previous one. Mediation analyses were based on significant relationships between childhood physical and sexual abuse, dissociation, and physical and sexual violence identified in the logistic regression analyses. Bootstrapping was used to assess whether dissociation mediated childhood abuse and violent victimization. Bootstrap estimates on 10,000 replications were obtained using a user written binary mediation ado program in conjunction with STATA’s native bootstrap code. Bootstrapping is generally recommended over other methods of testing indirect effects because it does not assume normality and has greater power while maintaining control over Type I error rates . Compared to the entire cohort , a lower proportion of study participants included in follow-up analyses were homeless at baseline ; no statistically significant differences existed between excluded and included participants according to drug use or mental health variables. Among those enrolled, 93% completed a six-month followup and were included in the current analysis . Approximately 70% of study participants included in the current analysis were women of color. The mean age was 47 years .