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Background Nearly 6 million deaths and over a half trillion dollars in healthcare costs worldwide are attributed to tobacco smoking each year. Extensive research efforts have been pursued to elucidate the molecular underpinnings of smoking addiction and facilitate cessation. In this study, we genotyped and obtained both resting state and task-based functional magnetic resonance imaging from 64 non-smokers and 42 smokers. Smokers were imaged after having smoked normally (“sated”) and after having not smoked for at least 12 h (“abstinent”). Results While abstinent smokers did not differ from non-smokers with respect to pairwise resting state functional connectivities (RSFCs) between 12 brain regions of interest, RSFCs involving the caudate and putamen of sated smokers significantly differed from those of non-smokers ( P  < 0.01). Further analyses of caudate and putamen activity during elicited experiences of reward and disappointment show that caudate activity during reward (CR) correlated with smoking status ( P  = 0.015). Moreover, abstinent smokers with lower CR experienced greater withdrawal symptoms ( P  = 0.024), which suggests CR may be related to smoking urges. Associations between genetic variants and CR, adjusted for smoking status, were identified by genome-wide association study (GWAS). Genes containing or exhibiting caudate-specific expression regulation by these variants were enriched within Gene Ontology terms that describe cytoskeleton functions, synaptic organization, and injury response ( P  < 0.001, FDR < 0.05). Conclusions By integrating genomic and imaging data, novel insights into potential mechanisms of caudate activation and homeostasis are revealed that may guide new directions of research toward improving our understanding of addiction pathology.

Background Little is known about the brain mechanisms underlying cancer‐associated weight loss (C‐WL) in humans despite this condition negatively affecting their quality of life and survival. We tested the hypothesis that patients with C‐WL have abnormal connectivity in homeostatic and hedonic brain pathways together with altered brain activity during food reward. Methods In 12 patients with cancer and 12 healthy controls, resting‐state functional connectivity (RSFC, resting brain activity observed through changes in blood flow in the brain which creates a blood oxygen level‐dependent signal that can be measured using functional magnetic resonance imaging) was used to compare three brain regions hypothesized to play a role in C‐WL: the hypothalamus (homeostatic), the nucleus accumbens (hedonic), and the habenula (an important regulator of reward). In addition, the brain reward response to juice was studied. Participants included 12 patients with histological diagnosis of incurable cancer (solid tumours), a European Cooperative Oncology Group performance status of 0–2, and a ≥5% involuntary body weight loss from pre‐illness over the previous 6 months and 12 non‐cancer controls matched for age, sex, and race. RSFC between the hypothalamus, nucleus accumbens, and habenula and brain striatum activity as measured by functional MRI during juice reward delivery events were the main outcome measures. Results After adjusting for BMI and compared with matched controls, patients with C‐WL were found to have reduced RSFC between the habenula and hypothalamus (P = 0.04) and between the habenula and nucleus accumbens (P = 0.014). Patients with C‐WL also had reduced juice reward responses in the striatum compared with controls. Conclusions In patients with C‐WL, reduced connectivity between both homeostatic and hedonic brain regions and the habenula and reduced juice reward were observed. Further research is needed to establish the relevance of the habenula and striatum in C‐WL.

The current study the relationship between eating disorders (EDs) and suicidal ideation and suicide attempt in adult inpatients. In particular, the present study investigated one potential mechanism, body dissatisfaction (BD), which may contribute to increased risk for suicide in adult ED patients. A sample of 432 psychiatric inpatients ranging from 18 to 65 years of age participated in the current study. Findings indicated that patients who have higher levels of BD also had higher levels of passive and active suicidal ideation and previous suicide attempts. Higher levels of BD were also related to increased suicidal ideation after controlling for depression and emotion dysregulation. Although additional risk factors for suicide should be investigated in adults with EDs, this study provides evidence regarding the relationship between BD and risk for suicide ideation and attempt. •Participants above the cut off for body dissatisfaction are more likely to endorse suicidal ideation than those who are not.•Participants above the cut off for body dissatisfaction are more likely to endorse previous attempts than those who are not.•Even after controlling for depression, body dissatisfaction above the cut off was associated with a higher suicidal ideation.•After controlling for emotion regulation, body dissatisfaction above the cut off was associated with a higher suicidal ideation.

The habenula is a small, bilateral brain structure located at the dorsal end of the diencephalon. This structure sends projections to the dopaminergic striatum and receives inputs from the limbic forebrain, making the habenula a unique modulator of cross-talk between these brain regions. Despite strong interest in the habenula during the seventies and eighties (Herkenham and Nauta, 1977; Beckstead, 1979; Beckstead et al., 1979; Herkenham and Nauta, 1979; Caldecott-Hazard et al., 1988), interest waned due to lack of a clearly identifiable functional role. Following Matsumoto and Hikosaka's seminal work on the lateral habenula as a predictor of negative reward in monkeys, the habenula has undergone a resurgence of scientific interest. Matsumoto and Hikosaka demonstrated an increase in habenular neuron firing when monkeys did not receive an expected juice reward (Matsumoto and Hikosaka, 2007). Studies have shown that increased habenular activity inactivates dopaminergic cells in the Rostromedial Tegmental Nucleus (RMTg) through GABAergic mechanisms (Jhou et al., 2009a,b). Additional studies link habenular activity to the regulation of serotonin and norepinephrine, suggesting the habenula modulates multiple brain systems (Strecker and Rosengren, 1989; Amat et al., 2001). These discoveries ushered in a series of new studies that have refocused attention on the lateral habenula and the importance of this small brain structure (Bianco and Wilson, 2009; Jhou et al., 2009a; Matsumoto and Hikosaka, 2009; Sartorius et al., 2010; Savitz et al., 2011). Recently, Geisler and Trimble reviewed this renewed interest in: The Lateral Habenula: No Longer Neglected (Geisler and Trimble, 2008). While the lateral habenula (LHb) has been extensively studied, the anatomically and histochemically distinct medial habenula (MHb) remains largely understudied. This short review argues that the MHb is functionally important and should be studied more aggressively.

Electronic cigarettes (e-cigarettes) are nicotine-delivery devices that are increasingly used, especially by young people. Because e-cigarettes lack many of the substances found in regular tobacco, they are often perceived as a safer smoking alternative, especially in high-risk situations such as pregnancy. However, studies suggest that it is exposure to nicotine that is most detrimental to prenatal development. The authors studied perceptions of tobacco and e-cigarette health risks using a multiple-choice survey. To study the perceived safety of e-cigarettes versus tobacco cigarettes, 184 modified Global Health Youth Surveys (WHO, http://www.who.int/tobacco/surveillance/gyts/en/ ) were completed electronically or on paper. Age range, smoking status, and perceptions about tobacco cigarettes and e-cigarettes were studied. The results verified that younger people use e-cigarettes more than older people. Tobacco cigarettes were perceived as more harmful than e-cigarettes to health in general, including lung cancer and pregnancy. Although more research is necessary, the authors postulate that the perception that e-cigarettes are safer during pregnancy may induce pregnant women to use these devices more freely. Given that nicotine is known to cause fetal harm, pregnant mothers who smoke e-cigarettes could cause even greater harm to the fetus because e-cigarettes are perceived as being safer than tobacco cigarettes. Until more data about the effects of nicotine during pregnancy are available, the authors advocate for labeling of e-cigarettes as potentially harmful, at least during pregnancy.

Abnormal interhemispheric functional connectivity correlates with several neurologic and psychiatric conditions, including depression, obsessive-compulsive disorder, schizophrenia, and stroke. Abnormal interhemispheric functional connectivity also correlates with abuse of cannabis and cocaine. In the current report, we evaluated whether tobacco abuse (i.e., cigarette smoking) is associated with altered interhemispheric connectivity. To that end, we examined resting state functional connectivity (RSFC) using magnetic resonance imaging (MRI) in short term tobacco deprived and smoking as usual tobacco smokers, and in non-smoker controls. Additionally, we compared diffusion tensor imaging (DTI) in the same subjects to study differences in white matter. The data reveal a significant increase in interhemispheric functional connectivity in sated tobacco smokers when compared to controls. This difference was larger in frontal regions, and was positively correlated with the average number of cigarettes smoked per day. In addition, we found a negative correlation between the number of DTI streamlines in the genual corpus callosum and the number of cigarettes smoked per day. Taken together, our results implicate changes in interhemispheric functional and anatomical connectivity in current cigarette smokers.

Background: Men who have sex with men accounted for 78% of the new HIV infections from 2007-2010 and are at an increased risk of contracting HIV due to substance use, unprotected anal sex, and multiple sex partners (CDC, 2012; CDC, 2014). Thus, I wanted to understand the demographic and psychosocial characteristics of methamphetamine-using MSM engaging in commercial sex encounters (CSE). The main objective of the study was to investigate the significance of life chaos, social support, and risk factors in methamphetamine-using men who have sex with men (MSM) engaging commercial sex encounters (CSE). Materials and Methods: 325 HIV-negative methamphetamine-using MSM who completed a questionnaire about recent substance use, sexual behavior, and various psychosocial measures through online recruitment procedures. Chi-square tests were carried out to obtain significant (p < 0.05) associations between risk factors and social support, life chaos, and engagement in CSE. The risk factors with significant associations obtained from the bivariate analysis were put in a logistic regression model to obtain adjusted odds ratios (aOR). Results: Engagement in CSE was associated with high life chaos (OR = 1.7, 95% CI = [1.01, 2.84]). High life chaos was associated with low social support (aOR = 3.78, 95% CI = [2.31, 6.22]) and being out to most or all people they knew (aOR = 2.29, 95% CI = [1.18, 4.42]). Low social support was associated with being Hispanic/Latino (aOR = 0.48, 95% CI = [0.25, 0.92]) and high life chaos (aOR = 3.97, 95% CI = [2.40, 6.57]). Conclusions: This study is significant because of its contribution to our understanding of the associations between risk factors, social support, life chaos, and the participation in CSE among methamphetamine-using MSM. It is also helps characterize life chaos and social support among methamphetamine-using MSM. This study introduces a new population who may engage in casual CSE rather than formal transactional CSE.