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Neurons in the periaqueductal gray (PAG) integrate negative emotions with the autonomic, neuroendocrine, and immune systems to facilitate responses to threat. Modern functional track tracing in animals and optogenetic and chemogenetic techniques show that the PAG is a rich substrate for the integration of active and passive responses to threat. In humans, the same regions of the PAG that give rise to adaptive anger/fight, fear/panic, depression/shutdown, pain, and predatory behaviors in response to challenging situations or overwhelming threats can become activated pathologically, resulting in symptoms that resemble those of psychiatric disorders. This review coalesces human and animal studies to link PAG neuropathways to specific elements of psychiatric diagnoses. The insights gained from this overview may eventually lead to new therapeutic interventions. New animal/rodent data that utilize modern functional track tracing with optogenetics and designer receptors exclusively activated by designer drugs (DREADDS) technology show that the periaqueductal gray (PAG) is a rich substrate for the integration of active and passive responses to threat. Human data suggest that the PAG may be dysregulated in psychopathology that drives maladaptive behavior. The neural circuit that connects the frontal cortex, amygdala, PAG, and pons medulla is hypothesized to be a focal point for psychopathology where stress and threat converge to usurp decision making for stimulus-appropriate motivated behavior. [ABSTRACT FROM AUTHOR]

Summary: Research indicates that perpetrators of domestic violence have abnormalities in central serotonin and testosterone metabolism, an increased sensitivity to anxiogenic stimuli, and an impaired neuro-connection between their cortex and the amygdala. Clinical evaluations show that perpetrators of domestic violence also have a distinguishing set of behaviors and diagnoses related to anxiety, depression, intermittent explosive disorder, and borderline personality disorder. In this paper we propose a model to understand how the biological abnormalities can potentially explain the behaviors and diagnoses exhibited by the perpetrators. Changes in the perpetrator’s neurotransmitters lead to a heightened sensitivity to environmental stimuli, anxiety, and conditioned fear. Lack of cortical input to the amygdala impairs the perpetrator’s ability to extinguish anxiety and/or conditioned fear and gives rise to either innate behaviors (e.g., fight, flight, and shut down) or learned fear avoidant behaviors designed to avoid anxiety (e.g., alcohol consumption, self-injurious acts, and obsessive behaviors). Linking conditioned fear and fear avoidance to the behaviors and psychiatric diagnoses will serve to change the way the medical community perceives and treats perpetrators of domestic violence. [Copyright &y& Elsevier]

In an earlier study, we reported that some perpetrators of domestic violence evidenced exaggerated fear-related responses to the panicogenic agent sodium lactate. In the current study, we employed positron emission tomography (PET) to investigate our hypothesis that there are differences in the neural structures and/or pathways that mediate and control the expression of fear-induced aggression in perpetrators of domestic violence. Regional cerebral glucose metabolism was measured in eight male perpetrators of domestic violence who fulfilled DSM-III-R criteria for alcohol dependence (DV-ALC), 11 male participants who fulfilled DSM-III-R criteria for alcohol dependence and had no history of interpersonal aggression (ALC) and 10 healthy male participants who did not fulfill criteria for any DSM-III-R axis I diagnosis and had no history of interpersonal aggression (HCS). DV-ALC had a significantly lower mean glucose uptake in the right hypothalamus compared to ALC and HCS. Correlations were performed between measures of glucose utilization in the brain structures involved in fear-induced aggression. The comparison of DV-ALC to HCS and to ALC differed in six and seven comparisons, respectively, involving various cortical and subcortical structures. HCS and ALC differed between the left thalamus and the left posterior orbitofrontal cortex. These PET findings show that some perpetrators of domestic violence differ from control participants in showing lower metabolism in the right hypothalamus and decreased correlations between cortical and subcortical brain structures. A possible psychological covariate of these changes in regional activity might be fear-induced aggression, but this hypothesis should be examined in larger study groups that undergo provocation during imaging. [Copyright &y& Elsevier]

Patients with bulimia (binge-purge syndrome) frequently complain that they consume a very restrictive diet to avoid gaining weight. To investigate this claim, 23 hospitalized bulimic patients were assessed daily for body weight, caloric intake, macronutrient diet content, activity measures, and body composition estimates during weight-stable periods. Bulimic patients ate fewer kilocalories per kilogram body weight (22.1 ± 4.6 kcal/kg) than did age-matched normal women (29.7 ± 6.5 kcal/kg) but had similar activity levels and body composition. Clinical variables, such as history of laxative abuse, anorexia, or obesity, and physiological characteristics, such as body weight, activity level, or dietary content, could not account for this difference in caloric consumption. Bulimic patients tended to eat a diet lower in fat and higher in protein than did control subjects. These results agree with observations of increased efficiency of caloric utilization in obese patients and support patient complaints of a tendency to gain weight easily. [ABSTRACT FROM AUTHOR]

We assessed whether level of physical activity of anorexia nervosa patients could influence caloric consumption needed to gain weight during hospitalization. Seventy-three percent of patients with anorexia nervosa had higher levels of motor activity than did healthy female volunteers. Anorectics required 8301 ± 2272 kcal (mean ± SD) to gain 1 kg body wt. Activity levels and caloric consumption needed to gain I kg were significantly correlated; the most active patients needed to consume more calories to gain weight. A median split of anorectic patients by level of activity showed that the group with lower activity levels gained 1 kg every 5.1 ± 1.2 d, whereas the group with higher activity levels gained 1 kg every 7.2 ± 1.9 d. These data suggest that the rate of weight gain can be accelerated, and the cost of hospitalization decreased, by restricting exercise in anorectics during refeeding. [ABSTRACT FROM AUTHOR]

Zinc deficiency is a frequent complication of alcohol abuse for multiple reasons including poor intake, increased excretion, internal redistribution and altered transporters. Zinc deficiency has been postulated to play a role in the development/progression of alcoholic liver disease (ALD). This study aimed to relate serum zinc levels with alcohol intake, serum albumin concentration and markers of inflammation and liver injury. One hundred and eight male and female very heavy drinking (≥10 drinks/day) individuals without clinical evidence of ALD were grouped by serum zinc concentration: normal-zinc group (zinc level≥71 μg/dl) included 67 patients, and low-zinc group (zinc level<71 μg/dl) included 41 patients. Data were collected on demographics, drinking history in last 90 days (heavy drinking days, HDD90 and total drinks, TD90), lifetime drinking history (LTDH) and clinical/ laboratory assessments. Our data show that in a very well-characterized, chronically heavy-drinking population without clinical evidence of liver disease, about 40% of subjects had low serum zinc levels. Frequency of heavy drinking days (HDD90) was significantly higher in the low-zinc group. Total drinks in past 90 days, LTDH and HDD90 showed significant associations with low zinc levels. The group with the low serum zinc had a higher aspartate aminotransferase/alanine aminotransferase ratio (good marker of alcoholic liver disease). Those in the low-zinc group had the lower albumin levels, a marker of hepatic synthetic function, and the highest C-reactive protein level, a biomarker of inflammation. [ABSTRACT FROM AUTHOR]

Background: Post-traumatic stress disorder (PTSD) is often comorbid with alcohol dependence (AD), but little is known about the characteristics of AD treatment-seeking inpatients with PTSD. We examined differences between treatment-seeking alcohol dependent inpatients with and without comorbid PTSD. We hypothesized that those with AD and PTSD would have higher levels of: (1) alcohol use and AD severity; (2) anxiety and mood disorders; (3) neuroticism.Methods: Individuals (N=411, mean age=41.7±10.0years) with AD were monitored over 30days in a suburban inpatient alcohol treatment setting. Patients were evaluated to identify AD and comorbid PTSD, mood and anxiety disorders, alcohol use and dependence severity, personality, and aggression.Results: Those with PTSD (19% of the sample) did not differ in the amount of alcohol consumed, but had greater: (1) severity of AD (p=0.001, d=0.44); (2) diagnosis of anxiety (p=0.000, OR=3.64) and mood (p=0.000, OR=4.83) disorders; and (3) levels of neuroticism (p<0.001, d=0.67) and aggression (p<0.001, d=0.81).Conclusions: AD patients with comorbid PTSD present a more severe phenotype across AD severity, frequency of anxiety and mood disorders, and levels of neuroticism and aggression. This group may benefit from concurrent treatment of both AD and PTSD. Future research can investigate neuroticism as a potential treatment target. [ABSTRACT FROM AUTHOR]

Abstract: Understanding the pathophysiology of addictive disorders is critical for development of new treatments. A major focus of addiction research has for a long time been on systems that mediate acute positively reinforcing effects of addictive drugs, most prominently the mesolimbic dopaminergic (DA) system and its connections. This research line has been successful in shedding light on the physiology of both natural and drug reward, but has not led to therapeutic breakthroughs. The role of classical reward systems is perhaps least clear in alcohol addiction. Here, recent work is summarized that points to some clinically important conclusions. First, important pharmacogenetic differences exist with regard to positively reinforcing effects of alcohol and the ability of this drug to activate classical reward pathways. This offers an opportunity for personalized treatment approaches in alcoholism. Second, brain stress and fear systems become pathologically activated in later stages of alcoholism and their activation is a major influence in escalation of alcohol intake, sensitization of stress responses, and susceptibility to relapse. These findings offer a new category of treatment mechanisms. Corticotropin-releasing hormone (CRH) signaling through CRH1 receptors is a major candidate target in this category, but recent data indicate that antagonists for substance P (SP) neurokinin 1 (NK1) receptors may have a similar potential. [ABSTRACT FROM AUTHOR]

Background: Elevated levels of corticotrophin-releasing hormone in the cortical-hippocampal-amygdala pathway increase fear and anxiety, which are components of defensive and violent behaviors. Prostaglandins E2 and F2α, which increase corticotrophin-releasing hormone RNA expression in this pathway, are reduced by dietary intakes of omega-3 fats. Methods: Among 21 perpetrators of domestic violence, cerebrospinal fluid and plasma were assessed for corticotrophin-releasing hormone and fatty acid compositions, respectively. Results: Lower plasma docosahexaenoic acid (wt% fatty acids) alone predicted greater cerebrospinal fluid corticotrophin-releasing hormone (pg/mL), in exponential (r = -.67, p < .006) and linear regressions (r = -0.68, p < .003 excluding four subjects with the highest docosahexaenate levels). Conclusions: In this small observational study, low plasma docosahexaenoic acid levels were correlated to higher cerebrospinal fluid corticotrophin-releasing hormone levels. Placebo controlled trials can determine if dietary omega-3 fatty acids can reduce excessive corticotrophin-releasing hormone levels in psychiatric illnesses. [Copyright &y& Elsevier]