CSF monoamine metabolites and lethality of suicide attempts in depressed patients with alcohol dependence

Neurobiology of Aggression-Review of Recent Findings and Relationship with Alcohol and Trauma

Aggression can be conceptualized as any behavior, physical or verbal, that involves attacking another person or animal with the intent of causing harm, pain or injury. Because of its high prevalence worldwide, aggression has remained a central clinical and public safety issue. Aggression can be caused by several risk factors, including biological and psychological, such as genetics and mental health disorders, and socioeconomic such as education, employment, financial status, and neighborhood. Research over the past few decades has also proposed a link between alcohol consumption and aggressive behaviors. Alcohol consumption can escalate aggressive behavior in humans, often leading to domestic violence or serious crimes. Converging lines of evidence have also shown that trauma and posttraumatic stress disorder (PTSD) could have a tremendous impact on behavior associated with both alcohol use problems and violence. However, although the link between trauma, alcohol, and aggression is well documented, the underlying neurobiological mechanisms and their impact on behavior have not been properly discussed. This article provides an overview of recent advances in understanding the translational neurobiological basis of aggression and its intricate links to alcoholism and trauma, focusing on behavior. It does so by shedding light from several perspectives, including in vivo imaging, genes, receptors, and neurotransmitters and their influence on human and animal behavior.

Social isolation-related depression accelerates ethanol intake via microglia-derived neuroinflammation

Social isolation is common in modern society and is a contributor to depressive disorders. People with depression are highly vulnerable to alcohol use, and abusive alcohol consumption is a well-known obstacle to treating depressive disorders. Using a mouse model involving isolation stress (IS) and/or ethanol intake, we investigated the mutual influence between IS-derived depressive and ethanol-seeking behaviors along with the underlying mechanisms. IS increased ethanol craving, which robustly exacerbated depressive-like behaviors. Ethanol intake activated the mesolimbic dopaminergic system, as evidenced by dopamine/tyrosine hydroxylase double-positive signals in the ventral tegmental area and c-Fos activity in the nucleus accumbens. IS-induced ethanol intake also reduced serotonergic activity, via microglial hyperactivation in raphe nuclei, that was notably attenuated by a microglial inhibitor (minocycline). Our study demonstrated that microglial activation is a key mediator in the vicious cycle between depression and alcohol consumption. We also propose that dopaminergic reward might be involved in this pathogenicity.

Research on potential biomarker correlates for suicidal behavior: A review

Suicide is a world health priority. Studies over the last few decades have revealed the complexity underlying the neurobiological mechanisms of suicide. Researchers have found dysregulations in the serotonergic system, the stress system, neural plasticity, lipid metabolism, and cell signaling pathways in relation to suicidal behaviors. These findings have provided more insight into the final path leading to suicide, at which medical intervention should be applied to prevent the action. However, because these molecular mechanisms have been implicated in both depression and suicide, the specificity of the mechanisms has been obscured. In this review, we summarize the main findings of studies on molecular mechanisms of suicidal behavior from the last 2 decades, with particular emphasis on the potential, independent role of each mechanism that is not contingent upon an underlying psychopathology, such as depression. The act of suicide is multifactorial; no single molecular mechanism is sufficient to fully account for the act. Knowledge of the reciprocal interactions among these molecular mechanisms and studying them in the context of brain circuitry by using neuroimaging techniques will provide a better understanding of the neurobiology of suicide.

Effect of voluntary alcohol consumption on Maoa expression in the mesocorticolimbic brain of adult male rats previously exposed to prolonged maternal separation

Discordant associations between monoamine oxidase A (MAOA) genotype and high alcohol drinking have been reported in human and non-human primates. Environmental influences likely moderate genetic susceptibility. The biological basis for this interplay remains elusive, and inconsistencies call for translational studies in which conditions can be controlled and brain tissue is accessible. The present study investigated whether early life stress and subsequent adult episodic alcohol consumption affect Maoa expression in stress- and reward-related brain regions in the rat. Outbred Wistar rats were exposed to rearing conditions associated with stress (prolonged maternal separation) or no stress during early life, and given free choice between alcohol and/or water in adulthood. Transcript levels of Maoa were assessed in the ventral tegmental area, nucleus accumbens (NAc), medial prefrontal cortex, cingulate cortex, amygdala and dorsal striatum (DS). Blood was collected to assess corticosterone levels. After alcohol consumption, lower blood corticosterone and Maoa expression in the NAc and DS were found in rats exposed to early life stress compared with control rats. An interaction between early life stress and voluntary alcohol intake was found in the NAc. Alcohol intake before death correlated negatively with Maoa expression in DS in high alcohol-drinking rats exposed to early life stress. Maoa expression is sensitive to adulthood voluntary alcohol consumption in the presence of early life stress in outbred rats. These findings add knowledge of the molecular basis of the previously reported associations between early life stress, MAOA and susceptibility to alcohol misuse.

Serum proteomic analysis reveals high frequency of haptoglobin deficiency and elevated thyroxine level in heroin addicts

Heroin addiction is a chronic, complex disease, often accompanied by other concomitant disorders, which may encumber effective prevention and treatment. To explore the differences in expression profiles of serum proteins in control and heroin addicts, we used two-dimensional electrophoresis coupled to MALDI-TOF/TOF, and identified 4 proteins of interest. Following validation of the increase in serum transthyretin, we assessed serum levels of thyroid stimulating hormone (TSH), triiodothyronine (T3), and thyroxine (T4), and observed a robust increase in T4 in heroin addicts compared to controls. In addition, we performed haptoglobin (Hp) phenotyping, and showed that the frequency of Hp0 (serum devoid of haptoglobin) was significantly higher in heroin addicts. Altogether, these findings indicated that: (1) thyroid hormone imbalance is present in heroin addicts; (2) anhaptoglobinemia (Hp0) might a risk factor or a deleterious effect of heroin abuse.

The interface between inhibition of descending noradrenergic pain control pathways and negative affects in post-traumatic pain patients

BACKGROUND

Animal studies have shown that surgical trauma activates the descending noradrenergic pathway. However, perioperative patients have decreased concentrations of noradrenaline (NA) in the cerebrospinal fluid (CSF). We proposed that the descending monoaminergic pathway is altered in post-traumatic pain patients and that CSF monoamine neurotransmitters may be more closely related to affective symptoms. We investigated the levels of monoamine neurotransmitters and assessed pain in these patients.

METHODS

Patients were divided into a post-traumatic pain group, a pain-free group, a painful labor group, and a pain-free labor group. CSF was collected from all patients, and concentrations of NA, 3-methoxy-4-hydroxyphenylglycol (MHPG), dopamine, homovanillic acid, and 5-hydroxyindoleacetic acid (5-HIAA) were measured by high-performance liquid chromatography.

RESULTS

In the post-traumatic pain group, lumbar CSF concentrations of NA and MHPG were significantly decreased (P < 0.01) compared to the control group. The post-traumatic pain group displayed a significant negative correlation between NA and the respective total value of the short form of the McGill pain questionnaire (SF-MPQ), SF-MPQ (affective), and visual analog scale (r = -0.388, r = -0.433, and r = -0.367; P < 0.05).

CONCLUSIONS

Post-traumatic pain patients demonstrated decreased concentrations of NAin CSF, indicating that descending noradrenergic pain control pathways may be inhibited. NA is more closely related to negative affects in post-traumatic pain patients.

Betaine prevents ethanol-induced oxidative stress and reduces total homocysteine in the rat cerebellum

Oxidative stress is a hypothesis for the association of reactive oxygen species with cerebrovascular and neurodegenerative diseases. Thus, we examined whether oral betaine can act as a preventive agent in ethanol-induced oxidative stress on the cerebellum of rats. Thirty-two adult male Sprague-Dawley rats were divided into four equal groups (control, ethanol, betaine, and betaine plus ethanol) with different dietary regimens and were followed up for 1 month. Total homocysteine (tHcy) of plasma and cerebellum homogenate was determined by an Axis(®) homocysteine EIA kit, and antioxidant enzyme (glutathione peroxidase (GPx), SOD, and CAT) activities of cerebellum homogenate were measured chemically by a spectrophotometer. Lipid peroxidation of cerebellum was shown by the measurement of thiobarbituric reactive substances (TBARS) via a spectrophotometer. Ethanol-induced hyperhomocysteinemia was manifested by an increase in the concentrations of tHcy in the plasma and cerebellum homogenates of the ethanol group, while ethanol-induced oxidative stress was indicated via an increase in lipid peroxidation marker (TBARS) in cerebellum homogenates of ethanol-treated rats. In contrast, betaine prevented hyperhomocysteinemia and oxidative stress in the betaine plus ethanol group as well as the betaine group. The results of the present investigation indicated that the protective effect of betaine is probably related to its ability to strengthen the cerebellum membrane cells by enhancement of antioxidant enzyme activity principally GPx, while the methyl donor effect of betaine to reduce hyperhomocysteinemia has been explained previously and confirmed in the present study.

Potential peripheral biological predictors of suicidal behavior in major depressive disorder

Previous studies have shown that dysfunctions in the serotonin system and hypothalamic-pituitary-adrenal axis (HPA) are associated strongly with suicidal behavior and suicide, especially among individuals with major depressive disorder. Suicidal behavior has been explained using both the stress-diathesis model and the state-trait interaction model. Specifically, diatheses, or trait-dependent risk factors, are associated with dysfunctions in the serotonin system; however, stress responses, or state-dependent factors, are associated with HPA hyperactivity. Decreases in cholesterol and brain-derived neurotrophic factor (BDNF) levels have been associated with impaired brain plasticity among individuals with suicidal behavior. Decreased serotonin functioning has been measured using cerebral spinal fluid (CSF) 5-HIAA, fenfluramine challenge studies, and platelet 5-HT2A receptors. HPA axis dysfunction has been evaluated with the dexamethasone suppression test. Cholesterol and BDNF levels have been measured in blood serum or plasma. Nevertheless, challenges to finding promising and accessible neurobiological predictors of suicide and suicidal behavior remain. As suicide behavior is a complex phenomenon, a combined or multidimensional approach, including each of the aforementioned methods, may be required to predict suicide risk among individuals with major depressive disorder.

Suicidal behavior and alcohol abuse

Suicide is an escalating public health problem, and alcohol use has consistently been implicated in the precipitation of suicidal behavior. Alcohol abuse may lead to suicidality through disinhibition, impulsiveness and impaired judgment, but it may also be used as a means to ease the distress associated with committing an act of suicide. We reviewed evidence of the relationship between alcohol use and suicide through a search of MedLine and PsychInfo electronic databases. Multiple genetically-related intermediate phenotypes might influence the relationship between alcohol and suicide. Psychiatric disorders, including psychosis, mood disorders and anxiety disorders, as well as susceptibility to stress, might increase the risk of suicidal behavior, but may also have reciprocal influences with alcohol drinking patterns. Increased suicide risk may be heralded by social withdrawal, breakdown of social bonds, and social marginalization, which are common outcomes of untreated alcohol abuse and dependence. People with alcohol dependence or depression should be screened for other psychiatric symptoms and for suicidality. Programs for suicide prevention must take into account drinking habits and should reinforce healthy behavioral patterns.

Does comorbid substance use disorder impair recovery from major depression with SSRI treatment? An analysis of the STAR*D level one treatment outcomes

Many patients with major depressive disorder (MDD) present with concurrent substance use disorders (SUDs), which has been thought to impair their response to antidepressants. Clinicians often delay antidepressant treatment until sustained sobriety has been established. Unfortunately, these comorbid subjects are typically excluded from depression treatment trials, leaving a gap in understanding the treatment outcomes. In the Sequenced Treatment Alternatives to Relieve Depression (STAR*D) study, 2876 adult outpatients diagnosed with nonpsychotic MDD were prospectively treated with the selective serotonin-reuptake inhibitor (SSRI), citalopram, and returned for at least one post-baseline visit. Participants with SUD (29%) and without SUD (71%) were compared in regard to baseline clinical and sociodemographic features and treatment response. The group with MDD and SUD was further subdivided into those with alcohol only, drug only, and both alcohol and drug use. Despite clear sociodemographic and clinical differences, there were no significant differences between groups in the time to achieve response or rates of response to citalopram; however, those who endorsed both alcohol and drug use had significantly reduced rates of remission and significantly increased times to reach remission compared to the MDD group without SUD. In addition, subjects with MDD and SUD had higher risk of psychiatric serious adverse events (3.3% vs. 1.5%) and hospitalization (2.8% vs. 1.2%). The results indicate that first-line treatment with citalopram in depressed patients with alcohol or drug use respond as well as those without SUD. More intensive treatment is most likely needed for MDD patients with both drug and alcohol use disorders.

Pathways to high-lethality suicide attempts in individuals with borderline personality disorder

The purpose of this study was to develop and test a model of high-lethality suicide attempts (HLSA) in individuals with Borderline Personality Disorder (BPD). An increased number of prior suicide attempts, substance use immediately prior to the attempt, and objective planning were proposed to lead directly to a HLSA, while aggression and impulsivity were hypothesized to lead indirectly to a HLSA through their associations with prior attempts. Path analysis revealed a revised model in which impulsivity was found to be significantly associated with both the lethality of the most recent attempt and the number of prior attempts. These results are discussed in terms of trait and crescendo models of suicidal behavior and their implications for suicide risk assessment among individuals with BPD.

Lower CSF MHPG predicts short-term risk for suicide attempt

Post-mortem studies document alterations in the central noradrenergic system in suicide. However, studies of non-fatal suicide attempts have, thus far, found no consistent relationship to the noradrenaline metabolite 3-methoxy-4-hydroxphenylglycol (MHPG) in cerebrospinal fluid (CSF). We therefore conducted a prospective study of CSF MHPG and suicidal acts in major depression and bipolar depression. CSF MHPG was assayed in 184 drug-free patients with DSM-IV major depressive disorder or bipolar disorder, presenting for treatment of a current depressive episode, who were then followed-up for up to 12 months. Survival analysis was conducted using Cox proportional hazards modelling to test association of CSF MHPG and future suicidal behaviour, and potential clinical mediators. Twenty-seven individuals made a suicide attempt (two fatal) in the follow-up period. Lower CSF MHPG predicted future suicide attempt or suicide (22% increase in hazard for each 10 pmol/ml lower MHPG, p=0.045). Lower CSF MHPG also correlated with higher medical lethality of future suicidal act (mean MHPG: 49+/-18 vs. 32+/-12 pmol/ml for low- vs. high-lethality, t=2.8, d.f.=25, p=0.009). Smoking and self-rated depression severity were also associated with lower CSF MHPG and with future suicide attempt, but were not statistically significant mediators in multivariate models. In conclusion, lower CSF MHPG is associated with short-term risk for future suicidal behaviour in the 12 months following a major depressive episode. Psychopathology that mediates the relationship between lower CSF MHPG and future suicidal behaviour needs to be identified.

Substance use disorders and risk for completed suicide

Substance use disorders are among the most frequent psychiatric disorders found in suicides. In psychological autopsy studies between 19% and 63% of all suicides suffered from substance use disorders, mostly from alcohol use disorders. Suicide risk is highly increased in substance use disorders, particularly in alcohol use disorders, and in co-morbid alcoholism and depression. So far, some risk factors for suicide have been identified in alcoholism. Nevertheless, various questions about the relationship between substance use disorders and suicide remain open, which indicate directions for future research.

Inferior frontal white matter volume and suicidality in schizophrenia

The neurobiology of suicidality in schizophrenia is largely unknown. We therefore assessed gray and white matter volumes associated with past suicidality and current self-aggression in schizophrenia. Fifty-five outpatients with schizophrenia (n=55) and healthy controls (n=55), matched for age, gender and handedness, were recruited. Ten patients had a life-time history of one or more suicide attempts. Current self-aggression was assessed using the Modified Overt Aggression Scale. High resolution structural magnetic resonance images were analyzed by voxel-based morphometry. We found significantly larger inferior frontal white matter volumes bilaterally in patients with a previous suicide attempt as compared with those patients without a history of suicidality. No other significant white or gray matter volume differences were observed. White matter volume in these regions did not differ between healthy controls and those patients without a previous suicide attempt. Furthermore, among patients, the level of current self-aggression showed a significant positive correlation with white matter volume in the same regions. Inferior frontal white matter alterations in fronto-temporo-limbic circuits may be associated with suicidality and self-aggression in schizophrenia.

Adrenocorticotropic hormone and cortisol plasma levels directly correlate with childhood neglect and depression measures in addicted patients

Hypothalamic-pituitary-adrenal (HPA) axis dysfunction has been reported to be involved in vulnerability to alcohol and drug dependence in humans, possibly underlying both addictive behaviour and depression susceptibility. The aim of the present study was to investigate the possible interactions between childhood adverse experiences, depressive symptoms and HPA axis function in addicted patients, in comparison with healthy control. Eighty-two abstinent heroin or cocaine dependent patients and 44 normal controls, matched for age and sex, completed the symptoms Check List-90 (SCL-90), measuring depressive symptoms, and the Childhood Experience of Care and Abuse Questionnaire. Blood samples were collected to determine adrenocorticotropic hormone (ACTH) and cortisol basal plasma levels at 8:00 and 8:30 a.m. Addicted individuals showed significantly higher neglect and depression scores and ACTH-cortisol plasma levels respect to control subjects. Depression scores at SCL-90 in addicted patients positively correlated with plasma ACTH and cortisol values. In turn, plasma ACTH levels were directly associated with childhood neglect measures, reaching statistical significance with 'mother-neglect' scores. Plasma cortisol levels were related to 'father antipathy' among cocaine addicts. These findings suggest the possibility that childhood experience of neglect and poor parent-child attachment may have a persistent effect on HPA axis function as an adult, partially contributing, together with genetic factors and other environmental conditions, to both depressive traits and substance abuse neurobiological vulnerability.

Depressive Störungen

Das Spektrum depressiver Erkrankungen macht den Hauptteil affektiver Störungen aus und gehört mit einer Inzidenz von ca. 8–20% zu den häufigsten psychischen Erkrankungen. Depressionen werden nach wie vor zu selten einer adäquaten Therapie (Antidepressiva, störungsspezifische Psychotherapie wie z. B. kognitive Verhaltenstherapie) zugeführt.

Prevalence and correlates of lifetime suicidal ideation and suicide attempts among Latino subgroups in the United States

OBJECTIVE

Limited data are available to understand the prevalence and correlates of suicidal behavior among U.S. Latino subgroups. This article compares the prevalence of lifetime suicidal ideation and suicide attempts among major U.S. Latino ethnic subgroups and identifies psycho-sociocultural factors associated with suicidal behaviors.

METHOD

The National Latino and Asian American Study includes Spanish- and English-speaking Mexicans, Puerto Ricans, Cubans, and other Latinos. A total of 2554 interviews were conducted in both English and Spanish by trained interviewers between May 2002 and November 2003. Lifetime psychiatric disorders were measured using the World Health Organization-Composite International Diagnostic Interview. Descriptive statistics and logistic models were used to determine demographic, clinical, cultural, and social correlates of lifetime suicidal ideation and suicide attempts.

RESULTS

The lifetime prevalence of suicidal ideation and suicide attempts among Latinos was 10.1% and 4.4%, respectively. Puerto Ricans were more likely to report ideation as compared with other Latino subgroups, but this difference was eliminated after adjustments for demographic, psychiatric, and sociocultural factors. Most lifetime suicide attempts described by Latinos were reported as occurring when they were under the age of 18 years. Any lifetime DSM-IV diagnoses, including dual diagnoses, were associated with an increased risk of lifetime suicidal ideation and suicide attempts among Latinos. In addition, female gender, acculturation (born in the United States and English speaking), and high levels of family conflict were independently and positively correlated with suicide attempts among Latinos, even among those without any psychiatric disorder.

CONCLUSIONS

These findings reinforce the importance of understanding the process of acculturation, the role of family, and the sociocultural context for suicide risk among Latinos. These should be considered in addition to psychiatric diagnoses and symptoms in Latino suicide research, treatment, and prevention, especially among young individuals.