Relationship between saliva opiorphin levels, pain threshold, and cutting number in adolescents with non suicidal self injury.

Various opinions have been suggested regarding non suicidal self-injury (NSSI) and pain relationship. Opiorphin is a recently found peptide that inhibits enkephaline-catabolizing enzymes. Analgesia caused by opiorphine has been demonstrated in animal experiments. No studies have examined the relationship between opiorphin and pain sensation until today. We aimed to investigate opiorphine and pain threshold among self-injuring adolescents. Adolescents aged 14-18 years were included in the study. The NSSI group consisted of 37 adolescents diagnosed with NSSI according to DSM-V Section 3, and the non-NSSI group consisted of 36 adolescents without any psychiatric disorder. We measured pain threshold with a pressure sensitive algometer device and analyzed saliva opiorphin levels by ELISA method. Mediation analysis was performed using Process Macro developed by Hayes. NSSI group had statistically significantly higher pain threshold and opiorphin levels than the non-NSSI group. There was a positive correlation between pain threshold values and opiorphin levels in the NSSI group. Also, a positive correlation between opiorphin levels and total cutting episode number was found. We searched for a probable relationship of pain threshold with episode number of each type of NSSI act. Accordingly, a positive correlation with two major act and a negative correlation with two minor act was shown. The opiorphine was found to be a mediator variable in the relationship between the pain threshold and the cutting number. The relationship between opiorphin, pain threshold and cutting number and their mediating effects with each other may highlight the pain-based biological origins of NSSI.

Coupling of autism genes to tissue-wide expression and dysfunction of synapse, calcium signalling and transcriptional regulation.

Autism Spectrum Disorder (ASD) is a heterogeneous disorder that is often accompanied with many co-morbidities. Recent genetic studies have identified various pathways from hundreds of candidate risk genes with varying levels of association to ASD. However, it is unknown which pathways are specific to the core symptoms or which are shared by the co-morbidities. We hypothesised that critical ASD candidates should appear widely across different scoring systems, and that comorbidity pathways should be constituted by genes expressed in the relevant tissues. We analysed the Simons Foundation for Autism Research Initiative (SFARI) database and four independently published scoring systems and identified 292 overlapping genes. We examined their mRNA expression using the Genotype-Tissue Expression (GTEx) database and validated protein expression levels using the human protein atlas (HPA) dataset. This led to clustering of the overlapping ASD genes into 2 groups; one with 91 genes primarily expressed in the central nervous system (CNS geneset) and another with 201 genes expressed in both CNS and peripheral tissues (CNS+PT geneset). Bioinformatic analyses showed a high enrichment of CNS development and synaptic transmission in the CNS geneset, and an enrichment of synapse, chromatin remodelling, gene regulation and endocrine signalling in the CNS+PT geneset. Calcium signalling and the glutamatergic synapse were found to be highly interconnected among pathways in the combined geneset. Our analyses demonstrate that 2/3 of ASD genes are expressed beyond the brain, which may impact peripheral function and involve in ASD co-morbidities, and relevant pathways may be explored for the treatment of ASD co-morbidities.

Downregulation of apolipoprotein A-IV in plasma & impaired reverse cholesterol transport in individuals with recent acts of deliberate self-harm.

Background & objectives: The major limiting factor in the prevention of suicide is the limited knowledge on molecular insights in individuals at risk. Identification of peripheral protein markers which can classify individuals at high-risk of suicide might aid in early diagnosis and effective medical intervention. The aim of the present study was, therefore, to analyze the differential regulation of plasma proteins in individuals with deliberate self-harm compared to controls. Methods: Using two-dimensional gel electrophoresis coupled with matrix-assisted laser desorption-ionization mass spectrometry, differentially expressed plasma proteins were identified in study participants with deliberate self-harm compared to age- and gender-matched controls. The finding was validated using mass spectrometry-based isotope-labelled relative quantification and Western blot analysis in a new set of individuals with deliberate self-harm and controls. Results: The plasma proteomic analysis showed that apolipoprotein A-IV (Apo A-IV ) was downregulated by 2.63-fold (confidence interval: 1.52-4.54) in individuals with deliberate self-harm (n=10) compared to matched controls, which was consistent in mass spectrometry-based relative quantification and Western blot analysis performed in an independent set of individuals with deliberate self-harm (n=18). In addition, plasma levels of total cholesterol, esterified cholesterol and high-density lipoprotein (HDL) were observed to be significantly lower individuals with deliberate self-harm compared to controls. Interpretation & conclusions: Apo A-IV, which plays a crucial role in the esterification of free cholesterol, was found to be downregulated with concomitantly decreased levels of HDL, esterified cholesterol and total cholesterol in individuals with deliberate self-harm compared to matched controls. The present findings might provide a link between the differential regulation of plasma proteins and the previously reported results on altered cholesterol levels in individuals with deliberate self-harm.

Adolescent nonsuicidal self-injury and cortisol response to the retrieval of adversity: A sibling study.

BACKGROUND: There is evidence for alterations in hypothalamus-pituitary-adrenal (HPA) axis response to the retrieval of traumatic events among individuals with Posttraumatic Stress Disorder. However, no study has so far investigated HPA response to trauma retrieval among individuals engaging in non-suicidal self-injury (NSSI). In the present study, we compared reports of childhood adversity (CA) between adolescents engaging in NSSI and their siblings and tested for differences in the cortisol response to the retrieval of CA. METHODS: The sample consisted of 32 adolescents engaging in NSSI (Mage = 15.8 years) and their siblings (Mage = 15.6 years). Standardized interviews were used for the assessment of CA, NSSI, and axis I diagnoses. Salivary cortisol was measured before and after the trauma interview. Basal HPA axis activity was measured in hair. RESULTS: Reports of CA were moderately interrelated between siblings. Adolescents engaging in NSSI reported more severe CA. A significant decrease of salivary cortisol during the trauma interview was found only in the NSSI group. The NSSI group had significantly higher hair cortisol levels. CONCLUSIONS: Moderate relations in siblings' reports of CA point to non-shared experiences that may play a role in the development of NSSI. In the NSSI group, the decrease of salivary cortisol during the interview may be explained by a downregulation of the HPA axis subsequent to the retrieval of former experience of CA.

The Pemoline Model of Self-Injurious Behavior: An Update.

Neurodevelopmental disorders typically comprise a complex constellation of behavioral symptoms and neurochemical abnormalities. However, many of the symptoms are inconsistently expressed within any one particular patient group or overlap between patient groups. In other words, there is usually heterogeneity of symptoms between diagnostic groups, and there is often partial homogeneity of symptoms across these groups. These include cognitive deficits, emotional lability, and perseverative or aberrant behaviors. Animal models of neurodevelopmental disorders typically reproduce or mimic specific genetic, neurochemical, and/or behavioral sequelae, although they typically fail to replicate the entire spectrum of biological and behavioral characteristics. Indeed, it may be impractical or even impossible to model the entire spectrum of characteristics of a disorder in any single animal model. A focus on one or more specific behavioral characteristics that occur in multiple neurodevelopmental disorders (e.g., self-injury) may be a fruitful strategy. The development of these behaviorally focused models may yield increased understanding of the endogenous and environmental factors that confer vulnerability for aberrant behaviors that commonly occur in these disorders. One such behaviorally focused animal model is the pemoline model of self-injurious behavior.

Activation in Children and Adolescents Treated With Selective Serotonin Reuptake Inhibitors: A Weighty Reason?

BACKGROUND: Activation is a behavioral adverse event related to the use of psychotropic medication. Its high incidence in pediatrics and in childhood-onset neuropsychiatric disorders suggests it may be linked to neurodevelopment. However, previous studies have scarcely examined the role that factors relevant to developmental pharmacokinetics, such as body weight, may play in the onset of activation in children and adolescents. METHODS: We conducted a retrospective analysis of hospitalized patients to identify the risk factors for activation in children and adolescents treated with selective serotonin reuptake inhibitors. Our focus was on factors related to development, including body weight, to explore the relationship between activation and neurodevelopmental processes. RESULTS: Among the 139 participants (mean age, 14 ± 2.3 years), activation appeared in 29 (20.9%). Age 12 years or younger and comorbid diagnosis of autism spectrum disorder were associated with statistically significant increases in the risk of activation, but no association was found regarding body weight. CONCLUSIONS: Our findings support the hypothesis that activation is closely linked to brain development processes. Longitudinal studies are needed to explore this line of research further.

Corticosterone Signaling and a Lateral Habenula-Ventral Tegmental Area Circuit Modulate Compulsive Self-Injurious Behavior in a Rat Model.

Self-injurious behavior (SIB) is commonly observed in patients with neuropsychiatric disorders, as well as in nonclinical populations with stress-related mental-health problems. However, the exact circuitry mechanisms underlying SIB have remained poorly understood. Here, with bilateral injection of muscimol into the entopeduncular nucleus (EP), we established a rat model of SIB. Following the muscimol injection, the male rats exhibited in a dose-dependent manner stereotypic self-biting behavior that lasted for hours and often resulted in wounds of various severities. The SIB was associated with an elevated level of serum corticosterone and could be exacerbated by enhancing the corticosterone signaling and, conversely, alleviated by inhibiting the corticosterone signaling. Activity mapping using c-fos immunostaining, combined with connectivity mapping using herpes simplex virus-based anterograde tracing from the EP and pseudorabies virus-based retrograde tracing from the masseter muscle, revealed the potential involvement of many brain areas in SIB. In particular, the lateral habenula (LHb) and the ventral tegmental area (VTA), the two connected brain areas involved in stress response and reward processing, showed a significant increase in neuronal activation during SIB. Furthermore, suppressing the LHb activity or modulating the GABAergic transmission in the VTA could significantly reduce the occurrence of SIB. These results demonstrate the importance of stress hormone signaling and the LHb-VTA circuit in modulating SIB resulting from EP malfunction, and suggest potential targets for therapeutic intervention of SIB and related disorders.SIGNIFICANCE STATEMENT Self-injurious behavior (SIB) occurs in ∼4% of the general population, with substantially higher occurrence among adolescents and patients of neuropsychiatric disorders. Stress has been linked to the occurrence of SIB, yet the underlying mechanisms have remained unclear. Using a rat model of SIB induced by disruption of activity in the entopeduncular nucleus (EP), we found that the behavior is regulated by stress and linked to corticosterone signaling. Viral tracing and c-fos immunostaining revealed the involvement of various subcortical areas, especially the EP-lateral habenula (LHb)-ventral tegmental area (VTA) circuit, in SIB. Furthermore, regulating activity in the LHb or the VTA alleviates SIB. These results may have implications in the development of new strategies for treating SIB.

Prefrontal cortex activation during cognitive interference in nonsuicidal self-injury.

Nonsuicidal self-injury (NSSI), deliberate behavior resulting in self-inflicted damage to oneself, is common, particularly among female adolescents, and may be a form of maladaptive emotion regulation. Cognitive interference, a specific type of processing associated with inhibiting prepotent responses in favor of less automatic ones, is utilized in treatment strategies to shift patients' thoughts and behaviors away from maladaptive responses and replace them with more adaptive ones. We examined cognitive interference processing using the Multi-Source Interference Task (MSIT) in females with NSSI behavior (n=15) and healthy control females (n=15). Functional magnetic resonance imaging (fMRI) data were collected concurrently. Results revealed similar between-group performance on the MSIT; however, women with NSSI behavior exhibited altered patterns of neural activation during the MSIT. Specifically, the NSSI group demonstrated increased cingulate cortex (CC) and decreased dorsolateral prefrontal cortex (DLPFC) activation compared to the control group. Further, within the NSSI group, DLPFC activation inversely correlated with emotional reactivity and self-reported impulsivity, suggesting that decreased DLPFC activation is associated with poorer emotional control and increased impulsivity. Taken together, these results indicate that women with NSSI behavior utilize different cortical areas during cognitive interference processing, which may have broader implications regarding the treatment efficacy of cognitive-based therapies.

Hypothalamic-pituitary-adrenal axis, childhood adversity and adolescent nonsuicidal self-injury.

BACKGROUND: Whereas childhood adversity (CA) and the hypothalamus-pituitary-adrenal (HPA) axis have been suggested to play a major role in the etiology of non-suicidal self-injury (NSSI), no study has thus far investigated both its associations and interactions with adolescent NSSI. METHOD: We investigated CA (antipathy, neglect, physical, psychological, and sexual abuse) and indices of HPA axis activity (salivary and hair cortisol) in a clinical sample of 26 adolescents engaging in NSSI and 26 age- and gender-matched healthy controls (HC). We used standardized interviews for the assessment of CA (CECA), NSSI (SITBI-G), and axis I diagnoses (MINI-KID). Salivary cortisol sampling was surveyed using a monitoring system and instructed via telephone calls. RESULTS: Adolescents engaging in NSSI exhibited significantly higher cortisol awakening responses compared to HC. No differences were found with respect to the diurnal slope or hair cortisol. In the presence of CA, healthy adolescents showed flatted diurnal cortisol slopes while those engaging in NSSI exhibited significantly steeper ones. CONCLUSIONS: Our findings indicate that adolescents engaging in NSSI may exhibit a stronger cortisol awakening response, potentially in expectation of strain. However, elevated cortisol levels may not be maintained throughout the day, especially among adolescents with a history of CA.

Routine biological tests in self-poisoning patients: results from an observational prospective multicenter study.

CONTEXT: Routine biological tests are frequently ordered in self-poisoning patients, but their clinical relevance is poorly studied. MATERIALS AND METHODS: This is a prospective multicentric observational study conducted in the emergency departments and intensive care units of 5 university and nonuniversity French hospitals. Adult self-poisoning patients without severely altered vital status on admission were prospectively included. RESULTS: Routine biological test (serum electrolytes and creatinine, liver enzymes, bilirubin, blood cell count, prothrombin time) ordering and results were analyzed. A total of 1027 patients were enrolled (age, 40.2 ± 14 years; women, 61.5%); no patient died during the hospital stay. Benzodiazepine was suspected in more than 70% of cases; 65% (range, 48%-80%) of patients had at least 1 routine biological test performed. At least 1 abnormal test was registered in 23% of these patients. Three factors were associated with abnormal test results: age older than 40 years, male sex, and poisoning with a drug known to alter routine tests (ie, acetaminophen, NSAIDs, metformine, lithium). Depending on these factors, abnormal results ranged from 14% to 48%. Unexpected severe life-threatening conditions were recorded in 6 patients. Only 3 patients were referred to the intensive care unit solely because of abnormal test results. CONCLUSION: Routine biological tests are commonly prescribed in nonsevere self-poisoning patients. Abnormal results are frequent but their relevance at bedside remains limited.

Cortisol levels and suicidal behavior: A meta-analysis.

Suicide is a major cause of death worldwide, responsible for 1.5% of all mortality. The causes of suicidal behavior are not fully understood. Dysregulated hypothalamic-pituitary-adrenal (HPA) axis activity, as measured by cortisol levels, is one potential risk factor. This meta-analytic review aimed (i) to estimate the strength and variability of the association between naturally fluctuating cortisol levels and suicidal behavior and (ii) to identify moderators of this relationship. A systematic literature search identified 27 studies (N=2226; 779 suicide attempters and 1447 non-attempters) that met the study eligibility criteria from a total of 417 unique records initially examined. Estimates of effect sizes (r) obtained from these studies were analysed using Comprehensive Meta-Analysis. In these analyses, we compared participants identified as having a past history of suicide attempt(s) to those with no such history. Study quality, mean age of sample and percentage of male participants were examined as potential moderators. Overall, there was no significant effect of suicide group on cortisol. However, significant associations between cortisol and suicide attempts were observed as a function of age. In studies where the mean age of the sample was below 40 years the association was positive (i.e., higher cortisol was associated with suicide attempts; r=.234, p<.001), and where the mean age was 40 or above the association was negative (i.e., lower cortisol was associated with suicide attempts; r=-.129, p<.001). These findings confirm that HPA axis activity, as indicated by age-dependent variations in cortisol levels, is associated with suicidal behavior. The challenge for theory and clinical practice is to explain the complete reversal of the association with age and to identify its clinical implications.

Post-dexamethasone cortisol, self-inflicted injury, and suicidal ideation among depressed adolescent girls.

Although the dexamethasone suppression test (DST) has limited use as a biomarker of depression given inadequate sensitivity and specificity, it marks prospective risk for suicide among adults. However, few studies have examined associations between the DST, suicidal ideation, and self-inflicted injury (SII) among adolescents, even though SII is the single best predictor of eventual suicide. We evaluated the DST as a correlate of suicidal ideation and retrospective reports of self-inflicted injury (SII) among adolescent girls, ages 13-17, with histories of depression (n = 28) or depression and self-harm (n = 29). Lower post-DST cortisol was associated with suicidal ideation and SII, over-and-above parent-reports and combined parent-/self-reports of internalizing and externalizing behavior. These findings are consistent with recent acquired capacity models of stress-related psychopathology in which hypothalamic-pituitary adrenal (HPA) axis function is altered through epigenetic/allostatic mechanisms among vulnerable individuals who incur adversity early in life.

Serotonergic genes and suicide: a systematic review.

Suicide is one of the leading causes of death in the world. Its aetiology is complex and diverse, however, epidemiological studies show that suicidal behavior is partly heritable. Neurobiological evidence implicates serotonergic dysfunction in suicidality, stimulating genetic research to focus on genes related to the serotonergic system. In this paper, we review evidence from studies examining the association between various serotonergic genes (Tryptophan Hydroxylase genes: TPH1; TPH2, Serotonin Transporter gene: 5-HTTLPR in SLC6A4, Serotonin Receptor genes: HTR1A, HTR2A, HTR1B, HTR2C and Monoamine Oxidase A gene: MAOA) and suicidal behavior. The data show associations between variation on the TPH1 gene and 5-HTTLPR gene and violent suicidal behavior in Caucasian populations, with the least inconsistencies. Results are mixed for the TPH2 gene and serotonin receptor genes, but for some genes, studies that include haplotypic analyses or that examine a larger coding region of the genes tend to provide more reliable results. Findings on endophenotypes of suicidality, such as aggression and impulsivity traits, show positive associations for the TPH1, HTR2A, and MAOA genes, but need further replication, since negative associations are also occasionally reported. Since genes can only partially explain suicidal risk, several studies during the past decade have tried to incorporate environmental factors in the susceptibility model. Studies to date show that variation on the 5-HTTLPR, MAOA and HTR2A gene can interact with stressful life events to increase risk for suicidal behavior. Limitations of case-control studies are discussed and future considerations are put forward with regard to endophenotypic measurements and gene-environment interactions.

The effects of acute tryptophan depletion on impulsivity and mood in adolescents engaging in non-suicidal self-injury.

OBJECTIVE: Non-suicidal self-injury (NSSI) is associated with impaired emotion regulation and impulsivity. Low serotonin (5-hydroxytryptamine) function is associated with NSSI, impaired emotion regulation and impulsivity. We investigated the effects of experimentally lowered 5-hydroxytryptamine activity, via acute tryptophan depletion (ATD), on impulsive action, reflection impulsivity and mood in female adolescents engaging in NSSI. METHODS: Thirty-two female adolescents engaging in NSSI participated in a parallel group ATD study. Following ATD, impulsive action was assessed using the Continuous Performance Test, Identical Pairs Version. Reflection impulsivity was assessed using the Matching Familiar Figures Test. Mood-lowering was examined using the Profile of Mood States. RESULTS: Following ATD, the participants showed an impulsive response style (as reflected in their low ß) and increased attentional capacity (as reflected in their elevated d'). ATD did not affect reflection impulsivity or mood. CONCLUSIONS: Acute tryptophan depletion caused an impulsive response style and increased attentional capacity. Importantly, the findings suggest that low serotonin function is a vulnerability among female adolescents for engaging in NSSI when in emotional distress.

Endogenous opioids and nonsuicidal self-injury: a mechanism of affect regulation.

Nonsuicidal self-injury (NSSI), or the purposeful destruction of body tissue occurring without suicidal intent, is a perplexing behavior as it goes against the natural instinct to maximize pleasure and minimize pain. One possible reason that people engage in NSSI is to regulate affect. However, the exact mechanisms that cause NSSI to lead to reduced feelings of negative affect remain unclear. Due to its involvement in the regulation of pain and emotion, the endogenous opioid system has been proposed to mediate the affect regulation effects of NSSI. The authors review evidence from multiple literatures to support this claim. Based on the current research, it is proposed that (1) individuals who engage in NSSI have lower baseline levels of endogenous opioids, (2) NSSI releases endogenous opioids, and (3) opioids released during NSSI regulate affect. These predictions are discussed in terms of previous models and other functions of NSSI.

Toward new avenues in the treatment of nonsuicidal self-injury.

The treatment of self-injury, or self-destruction of one's own body tissue, has become a new focus for both researchers and clinicians. Traditionally, the field of self-injury has distinguished between the behaviors exhibited among individuals with a developmental disability (self-injurious behaviors [SIBs]) and those present within a normative population (nonsuicidal self-injury [NSSI]). Despite this distinction, many pharmacotherapies for self-injury have been administered for both populations. The current review begins by summarizing the available efficacy studies investigating common pharmacological interventions in the treatment of self-injury. These studies are organized based on the most empirically supported neurochemical pathways in the development or maintenance of NSSI: endogenous opiods and monoamines. Although significant advances have been made in the field, conclusions based on efficacy studies of the pharmacological interventions used in the treatment of self-injury have been somewhat inconsistent. Finally, the review includes a discussion about potential avenues in the pharmacological treatment of NSSI via animal models of self-injury. Animal models present a unique opportunity to test neurobiological theories of self-injury using a controlled, systematic approach. Clinical considerations are presented as they relate to the available research findings and best practices in the treatment of self-injury.

Increased IL-1ß reactivity upon a glucose challenge in patients with deliberate self-harm.

OBJECTIVE: A disturbed glucose metabolism has been observed in patients with aggressive behaviour. Interleukin (IL)-1ß is a pro-inflammatory cytokine that can induce hypoglycaemia, but has also been suggested to be involved in the generation of hostility and aggression. Our group has previously shown an altered glucose metabolism in patients with self-inflicted aggressive behaviour. We investigated the hypothesis that the levels of IL-1ß would be increased in these patients, because this might explain the aberrant glucose metabolism and add further knowledge to the aetiology of self-inflicted aggressive behaviour. METHOD: We investigated plasma cytokine changes in 13 patients with borderline personality disorder and 13 healthy controls during a 5-h glucose challenge. Plasma samples were analysed for cytokines IL-1ß, TNF-α and IL-6 using high-sensitivity multiplex ELISA. Psychiatric symptoms were rated using the Aggression Questionnaire Revised Swedish Version. RESULTS: Basal plasma levels of the three cytokines did not differ between patients and controls. All three cytokines reacted significantly upon the glucose challenge. The increase in IL-1ß levels in response to glucose was significantly greater in patients than in controls. Furthermore, IL-1ß reactivity was associated with symptoms of hostility. CONCLUSION: An increased reactivity of IL-1ß might be part of a pathogenetic mechanism in patients with deliberate self-harm.

A prospective study of lipids and serotonin as risk markers of violence and self-harm in acute psychiatric patients.

Cross-sectional studies have reported an association between lipids and serotonin levels and aggression, but a literature search revealed a paucity of prospective studies. Subjects of the present naturalistic study were 254 of all (489) involuntary and voluntary acutely admitted patients to a psychiatric hospital during 1year. Serum lipids and platelet serotonin at admission were prospectively compared with recorded intra-institutional and 1-year post-discharge violence and self-harm. Total cholesterol had a significant negative relationship to inpatient suicidal behaviour and inpatient violent behaviour and to 3-month post-discharge violent behaviour. Triglycerides were a significant marker of inpatient self-mutilation and of self-mutilation in combination with suicidal behaviour at 3 and 12 months of follow-up. High-density lipoprotein (HDL) had a significant negative relationship to violence at 12-months, and to repeated violence in seven patients with two or more admissions. The post-discharge relationships between total cholesterol and violence and between triglycerides and self-harm remained significant even when controlling for other possible explanatory variables in a multivariate model. Results did not change after controlling for current medication at admission. There was no association between platelet serotonin and violence or self-harm. Future research may examine if lipid measurements add incremental validity to established clinical risk assessment procedures of violent and self-harm behaviour.

Altered glucose tolerance in women with deliberate self-harm.

Disturbances in glucose metabolism are of importance for violent behaviour in men, but studies in women are lacking. We used the 5h-oral glucose tolerance test (OGTT) in this study of 17 female psychiatric patients, selected for violent behaviour directed against themselves (deliberate self-harm) and 17 healthy controls matched for age and BMI. Following OGTT, patients had higher glucose levels at 30 min (p=0.007) and increased glucagon area under the curve (p=0.011). Since a co-morbid eating disorder might affect results, we as a post-hoc analysis subgrouped the patients and found that the increased glucagon levels only were present in patients with an eating disorder. In contrast, those without an eating disorder showed a significantly lower p-glucose nadir (p=0.015) and unaltered glucagon levels compared to controls. There were no significant differences in insulin and C-peptide levels between patients and controls. We conclude that deliberate self-harm in women may be associated with alterations in carbohydrate metabolism in certain groups. Eating disorder is a confounding factor.

Acute tryptophan depletion and self-injurious behavior in aggressive patients and healthy volunteers.

RATIONALE: An association between serotonin (5-HT) activity and self-injurious (i.e., self-aggressive) behavior across the spectrum of lethality (from self-mutilation through completed suicide) is a well-replicated finding. Studies to date, however, have relied on nonexperimental designs to examine this relationship, limiting the causal inferences that can be drawn about the role of 5-HT in self-aggressive behavior. OBJECTIVE: Examine the effect of experimentally altered 5-HT activity (via dietary tryptophan depletion) on self-aggressive behavior among adults with and without intermittent explosive disorder (IED). Individuals with a marked history of aggression, such as those with IED, are characterized by compromised 5-HT and heightened risk for self-aggression, making this a population of interest for examining the proposed relations. MATERIALS AND METHODS: IED patients (n = 16) and healthy controls (n = 16) received a tryptophan depletion and a placebo drink on separate days at least 1 week apart. Self-aggressive behavior was assessed on both study days using a well-validated laboratory-based behavioral assessment with self-aggression defined as the intensity of shock self-administered. RESULTS: Tryptophan depletion facilitated selection of more intense shocks, on average, in both groups. Patients with IED were also more self-aggressive overall than healthy volunteers. No IED by drink condition interactions were found. CONCLUSION: Experimentally lowered 5-HT bioavailability enhances overall self-injurious behavior irrespective of aggression history.