Andréa L. Hobkirk

Mind Your Words: Positive and Negative Items Create Method Effects on the Five Facet Mindfulness Questionnaire

Mindfulness, a construct that entails moment-to-moment effort to be aware of present experiences and positive attitudinal features, has become integrated into the sciences. The Five Facet Mindfulness Questionnaire (FFMQ), one popular measure of mindfulness, exhibits different responses to positively and negatively worded items in nonmeditating groups. The current study employed confirmatory factor analysis with a large undergraduate sample to examine the validity of a hierarchical mindfulness model and whether response patterns related to item wording arose from method effects. Results indicated that a correlated facets model better explained the data and that negative and positive wording constituted substantive method effects. This study suggests that the FFMQ measures components that may relate to, but do not seem to directly reflect, a latent variable of mindfulness. The authors recommend against the use of an FFMQ total score, favoring individual scale scores, and further examination of method effects in mindfulness scales.

Subtypes of attention deficit-hyperactivity disorder (ADHD) and cannabis use.

The current study examined the association between subtypes of attention-deficit/hyperactivity disorder (ADHD) and cannabis use within a sample of 2811 current users. Data were collected in 2012 from a national U.S. survey of cannabis users. A series of logistic regression equations and chi-squares were assessed for proportional differences between users. When asked about the ADHD symptoms they have experienced when not using cannabis, a higher proportion of daily users met symptom criteria for an ADHD diagnoses of the subtypes that include hyperactive–impulsive symptoms than the inattentive subtype. For nondaily users, the proportions of users meeting symptom criteria did not differ by subtype. These results have implications for identifying which individuals with ADHD might be more likely to self-medicate using cannabis. Furthermore, these findings indirectly support research linking relevant cannabinoid receptors to regulatory control.

Cocaine dependence modulates the effect of HIV infection on brain activation during intertemporal decision making

BACKGROUND Both HIV infection and chronic cocaine use alter the neural circuitry of decision making, but the interactive effects of these commonly comorbid conditions have not been adequately examined. This study tested how cocaine moderates HIV-related neural activation during an intertemporal decision-making task. METHODS The sample included 73 participants who differed on cocaine and HIV status (18 COC+/HIV+, 19 COC+/HIV-, 19 COC-/HIV+, 17 COC-/HIV-). Participants made choices between smaller, sooner and larger, delayed rewards while undergoing functional MRI. Choices varied in difficulty based on subjective value: hard (equivalently valued), easy (disparately valued), and control choices. A mixed-effects model controlling for education and smoking identified main and interactive effects of HIV and COC during hard relative to easy choices (difficulty contrast). RESULTS COC+ status was associated with lower activation in bilateral frontal gyri and right insular and posterior parietal cortices. HIV+ status was associated with higher activation in the visual cortex, but lower activation in bilateral prefrontal cortices and cerebellum and left posterior parietal cortex. COC moderated the effects of HIV in several clusters centered in the bilateral prefrontal cortices and cerebellum. In post-hoc analyses, there were significant effects of HIV status on activation for COC+, but not COC-, participants; interaction effects remained after controlling for polysubstance use. CONCLUSION Cocaine use may diminish the compensatory neural activation often seen among HIV+ samples during decision making. Our results highlight the importance of examining the neuropsychiatric effects of comorbid medical conditions to identify potential neural targets for cognitive remediation interventions.

Mediators of interpersonal violence and drug addiction severity among methamphetamine users in Cape Town, South Africa.

South Africa has high rates of interpersonal violence and a rapidly growing methamphetamine epidemic. Previous research has linked experiences of interpersonal violence to higher rates of substance use, and identified mental health constructs as potential mediators of this association. The aim of this study was to examine the relationship between interpersonal violence and addiction severity among active methamphetamine users in Cape Town, South Africa, and to explore symptoms of posttraumatic stress disorder (PTSD) and substance use coping as mediators of this relationship. A community sample of 360 methamphetamine users was recruited through respondent driven sampling and surveyed on their experiences of violence, mental health, coping, and drug use and severity. A series of one-way ANOVAs were conducted to examine the relationship of self-reported interpersonal violence with drug addiction severity, and multiple mediation analyses were used to determine if PTSD symptoms and substance use coping mediated this relationship. The majority (87%) of the sample reported experiencing at least one instance of interpersonal violence in their lifetime, and the number of violent experiences was associated with increased drug addiction severity. PTSD and substance use coping were significant mediators of this association. Only the indirect effect of substance use coping remained significant for the female sample when the mediation model was conducted separately for men and women. The findings point to the need for integrated treatments that address drug use and PTSD for methamphetamine users in South Africa and highlight the importance of coping interventions for women.

Cardiovascular Reactivity to and Recovery from Stressful Tasks Following a Mindfulness Analog in College Students with a Family History of Hypertension

OBJECTIVES Ninety-seven (97) undergraduates with a family history of hypertension participated in a study that evaluated the effects of a brief mindfulness-induction on cardiovascular reactivity and recovery to two stressors. MATERIALS AND METHODS Participants were randomized to either a mindfulness-induction or control condition and were then exposed to the cold pressor task (CPT) followed by the mirror-tracing task (MT). Blood pressure and heart rate were measured at baseline and postinduction, as well as during and immediately following each stressor. RESULTS There were no group differences in reactivity to either stressor. Participants in the mindfulness-analog condition experienced significantly greater latency to systolic blood pressure recovery following the CPT and a tendency toward greater latency to diastolic blood pressure recovery, although these findings were not replicated with the MT task. CONCLUSIONS These results are contrary to what was hypothesized and to the anecdotal evidence available regarding effects of comprehensive mindfulness interventions on reactivity. The findings are discussed with respect to purported mechanisms of mindfulness and learning theory.

The role of substance use coping in the relation between childhood sexual abuse and depression among methamphetamine users in South Africa

Objective: Childhood sexual abuse (CSA) is a critical global health issue associated with poor psychosocial outcomes. Individuals with CSA histories are at risk for drug use, which is a growing problem in the Western Cape of South Africa. The present study of methamphetamine users in this region examined whether substance use coping, a contextually relevant type of avoidance-based coping, mediates the relation between CSA and depressive symptoms. Method: Participants included 161 men and 108 women seeking treatment for methamphetamine use. Participants completed a computer-assisted survey and a face-to-face interview with clinic staff to evaluate history of CSA, current substance use severity and coping, and current depressive symptoms. Results: Nearly a third of participants reported a history of CSA, and the average methamphetamine use severity score exceeded the threshold of high risk. A history of CSA was significantly associated with higher substance use coping and more depression symptoms. Substance use coping was a significant mediator of the association between CSA and depression symptoms. Conclusions: In this study of high-risk methamphetamine users, substance use coping emerged as a common means of managing stress, especially for those with a history of CSA, which was further linked to depressive symptoms. These findings underscore the potential benefit of integrating coping interventions and mental health treatment into substance abuse treatment programs, particularly for those with a history of childhood abuse and violence.

Intimate partner violence among men and women who use methamphetamine: A mixed-methods study in South Africa.

INTRODUCTION The prevalence of methamphetamine use has risen dramatically in parts of South Africa. Globally, methamphetamine has been linked to intimate partner violence (IPV) and other forms of aggression. The aim of this mixed-methods study was to examine the experiences of physical IPV and its contextual factors among methamphetamine users in an urban community in Cape Town, South Africa. METHODS Active methamphetamine users were recruited using respondent driven sampling. All participants (n = 360) completed structured surveys, and a subset (n = 30) completed in-depth interviews with discussions of personal IPV experiences. Quantitative data were examined separately by gender, and regression models were used to identify factors that were associated with physical IPV victimisation and perpetration. Qualitative data were analysed to provide contextual understanding. RESULTS In the past 3 months, 47% of women and 31% of men reported being a victim of IPV, and 30% of women and 28% men reported being a perpetrator of IPV. Victimisation and perpetration were highly correlated, and both were significantly associated with histories of other traumas. Although the survey data suggests gender equivalence in IPV, the qualitative data provides a more nuanced context, with female victimisation by male partners being particularly frequent and intense. In narratives, IPV was a product of male aggression while using methamphetamine, norms around sex trading and gender-based attitudes endorsing violence against women. CONCLUSION Addiction to methamphetamine creates heightened risks of IPV, especially among those with previous traumas. The findings emphasise the importance of identifying and addressing IPV among methamphetamine users in South Africa. [Watt MH, Guidera KE, Hobkirk AL, Skinner D, Meade CS. Intimate partner violence among men and women who use methamphetamine: A mixed-methods study in South Africa. Drug Alcohol Rev 2017;36:97-106].

Exploring the relationship between posttraumatic stress disorder symptoms and momentary heart rate variability

OBJECTIVE Exposure to trauma-related cues has been associated with a prolonged decrease in heart rate variability (HRV) under laboratory conditions, however the relationship between PTSD symptoms and HRV has not been evaluated during everyday life. The present study sought to determine whether Posttraumatic Stress Disorder (PTSD) symptoms reported during everyday life were related to reduced HRV. METHODOLOGY Eighty-three young adults with PTSD underwent 24-hour Holter monitoring, during which PTSD symptoms were measured using ecological momentary assessment (EMA). Multilevel modeling was used to examine the association between PTSD symptom severity and low frequency (LF) and high frequency (HF) HRV. RESULTS PTSD symptoms were associated with reductions in LF HRV, independently of age and activity level. There was no significant association between PTSD symptom levels and HF HRV. CONCLUSIONS These results indicate that an association between momentary PTSD symptom severity and reduced LF HRV is significant and observable in young adults with PTSD. Findings highlight the need for cardiovascular screening in young adults with PTSD and early interventions that target physiological reactivity in PTSD.

Primary and Secondary HIV Prevention Among Persons with Severe Mental Illness: Recent Findings

Persons with severe mental illness (SMI) have been disproportionately affected by the HIV epidemic, with higher rates of HIV prevalence and morbidity than the general population. Recent research has advanced our understanding of the complex factors that influence primary and secondary HIV prevention for those with SMI. Sex risk in this population is associated with socioeconomic factors (e.g., low income, history of verbal violence) and other health risk behaviors (e.g., substance use, no prior HIV testing). Several interventions are effective at reducing risk behavior, and reviews highlight the need for more well-controlled studies that assess long-term outcomes. Recent research has elucidated barriers that interfere with HIV treatment for SMI populations, including individual (e.g., apathy, substance use), social (e.g., stigma), and system factors (e.g., transportation, clinic wait times). Interventions that coordinate HIV care for individuals with SMI show promise as cost-effective methods for improving medication adherence and quality of life.

Changes in resting state functional brain connectivity and withdrawal symptoms are associated with acute electronic cigarette use

Resting state functional brain connectivity (rsFC) may be an important neuromarker of smoking behavior. Prior research has shown, among cigarette smokers, that nicotine administration alters rsFC within frontal and parietal cortices involved in executive control, as well as striatal regions that drive reward processing. These changes in rsFC have been associated with reductions in withdrawal symptom severity. We currently have a limited understanding of how rsFC is affected by the use of electronic cigarettes (ecigs), an increasingly popular class of products, the members of which deliver nicotine with varying effectiveness. The current study used fMRI to determine the effects of ecig use on rsFC and withdrawal symptoms. Independent component, dual regression, and permutation analyses were conducted on rsFC collected from ecig users before and after an ecig use episode (n=9) that occurred after 14h of nicotine abstinence. Similar to the known effects of nicotine administration, ecig use decreased rsFC of two clusters in the right frontal pole and frontal medial cortex with an attentional control salience network, and decreased rsFC of five clusters in the left thalamus, insula, and brain stem with a reward network encompassing the striatum. Ecig use increased inverse coupling between the prefrontal reward network and the right frontoparietal executive control network. Reductions in craving and difficulty with concentration were correlated with decreases in coupling strength between reward and executive control networks. These preliminary results suggest that the effects of ecig use on rsFC are similar to those seen with nicotine administration in other forms. In order to gain insight into the addictive potential of ecigs, further research is needed to understand the neural influence of ecigs across the range of nicotine delivery within this class of products.