Less NMDA Receptor Binding in Dorsolateral Prefrontal Cortex and Anterior Cingulate Cortex Associated With Reported Early-Life Adversity but Not Suicide.

BACKGROUND: Glutamate is an excitatory neurotransmitter binding to 3 classes of receptors, including the N-methyl, D-aspartate (NMDA) receptor. NMDA receptor binding is lower in major depression disorder and suicide. NMDA receptor blocking with ketamine can have antidepressant and anti-suicide effects. Early-life adversity (ELA) may cause glutamate-mediated excitotoxicity and is more common with major depression disorder and in suicide decedents. We sought to determine whether NMDA-receptor binding is altered with suicide and ELA. METHODS: A total 52 postmortem cases were organized as 13 quadruplets of suicide and non-suicide decedents matched for age, sex, and postmortem interval, with or without reported ELA (≤16 years). Tissue blocks containing dorsal prefrontal (BA8), dorsolateral prefrontal (BA9), or anterior cingulate (BA24) cortex were collected at autopsy. Psychiatrically healthy controls and suicide decedents underwent psychological autopsy to determine psychiatric diagnoses and details of childhood adversity. NMDA receptor binding was determined by quantitative autoradiography of [3H]MK-801 binding (displaced by unlabeled MK-801) in 20-µm-thick sections. RESULTS: [3H]MK-801 binding was not associated with suicide in BA8, BA9, or BA24. However, [3H]MK-801 binding with ELA was less in BA8, BA9, and BA24 independent of suicide (P < .05). [3H]MK-801 binding was not associated with age or postmortem interval in any brain region or group. CONCLUSIONS: Less NMDA receptor binding with ELA is consistent with the hypothesis that stress can cause excitotoxicity via excessive glutamate, causing either NMDA receptor downregulation or less receptor binding due to neuron loss consequent to the excitotoxicity.

Sudden Unexpected Death in Epilepsy: Incidence, Risk Factors, and Proposed Mechanisms.

Epilepsy is a common neurological disorder associated with increased morbidity and mortality, including premature death from different causes. Sudden unexpected death in epilepsy, or SUDEP, is one of the most common causes of death in people with epilepsy and originally brought to light by medical examiners. It accounts for 5% to 30% of all deaths in individuals with epilepsy and up to 50% in individuals with medically refractory epilepsy. It is commonly associated with a history of generalized tonic-clonic seizures and may be mitigated by other electroclinical risk factors, such as postictal electroencephalographic suppression, prone position, altered heart rate variability, conduction abnormalities, gender, or antiepileptic medications, to name a few. More recently, potential neuroimaging biomarkers have also been identified. Still, despite the increased mortality risk in people with epilepsy due to SUDEP, little is known about its underlying pathophysiology. The pathogenesis is likely to be multifactorial, resulting in neurogenic pulmonary edema or, in some cases, fatal cardiac arrhythmias. Medical examiners can provide an important role in our understanding of the magnitude of the problem and ongoing research into the underlying mechanisms. In this review, we discuss diagnostic criteria, incidence, risk factors, and current theories regarding the pathophysiology of SUDEP.

Ketamine versus midazolam in bipolar depression with suicidal thoughts: A pilot midazolam-controlled randomized clinical trial.

OBJECTIVES: To evaluate feasibility and effects of a sub-anesthetic infusion dose of ketamine versus midazolam on suicidal ideation in bipolar depression. Neurocognitive, blood and saliva biomarkers were explored. METHODS: Sixteen participants with bipolar depression and a Scale for Suicidal Ideation (SSI) score of ≥4 were randomized to ketamine (0.5 mg/kg) or midazolam (0.02 mg/kg). Current pharmacotherapy was maintained excluding benzodiazepines within 24 hours. The primary clinical outcome was SSI score on day 1 post-infusion. RESULTS: Results supported feasibility. Mean reduction of SSI after ketamine infusion was almost 6 points greater than after midazolam, although this was not statistically significant (estimate=5.84, SE=3.01, t=1.94, P=.074, 95% confidence interval ([CI)]=-0.65 to 12.31). The number needed to treat for response (SSI <4 and at least 50% below baseline) was 2.2, and for remission (SSI=0) was 3.2. The strongest neurocognitive correlation was between memory improvement on the Selective Reminding Test (SRT) and reduction in SSI score on day 1 after ketamine (ρ=-.89, P=.007). Pre- to post-infusion decrease in serum brain derived neurotrophic factor (BDNF) correlated with reduction in SSI from baseline to day 1 after ketamine (n=5, ρ=0.90, P=.037) but not midazolam (P=.087). CONCLUSIONS: The study demonstrated feasibility. Suicidal thoughts were lower after ketamine than after midazolam at a trend level of significance, likely due to the small pilot sample. Memory improvement and BDNF are promising biomarkers. Replication is needed in an adequately powered full-scale trial.

Anxiety in major depression and cerebrospinal fluid free gamma-aminobutyric acid.

BACKGROUND: Low gamma-aminobutyric acid (GABA) is implicated in both anxiety and depression pathophysiology. They are often comorbid, but most clinical studies have not examined these relationships separately. We investigated the relationship of cerebrospinal fluid (CSF) free GABA to the anxiety and depression components of a major depressive episode (MDE) and to monoamine systems. METHODS AND MATERIALS: Patients with a DSM-IV major depressive episode (N = 167: 130 major depressive disorder; 37 bipolar disorder) and healthy volunteers (N = 38) had CSF free GABA measured by gas chromatography mass spectroscopy. Monoamine metabolites were assayed by high performance liquid chromatography. Symptomatology was assessed by Hamilton depression rating scale. RESULTS: Psychic anxiety severity increased with age and correlated with lower CSF free GABA, controlling for age. CSF free GABA declined with age but was not related to depression severity. Other monoamine metabolites correlated positively with CSF GABA but not with psychic anxiety or depression severity. CSF free GABA was lower in MDD compared with bipolar disorder and healthy volunteers. GABA levels did not differ based on a suicide attempt history in mood disorders. Recent exposure to benzodiazepines, but not alcohol or past alcoholism, was associated with a statistical trend for more severe anxiety and lower CSF GABA. CONCLUSIONS: Lower CSF GABA may explain increasing severity of psychic anxiety in major depression with increasing age. This relationship is not seen with monoamine metabolites, suggesting treatments targeting the GABAergic system should be evaluated in treatment-resistant anxious major depression and in older patients.

Familial transmission of parental mood disorders: unipolar and bipolar disorders in offspring.

OBJECTIVES: Offspring of depressed parents are at increased risk for psychiatric disorders. Although bipolar disorder (BD) and major depressive disorder (MDD) are both found in the same families, it is not clear whether transmission to offspring of BD or MDD tends to occur from parents with the same mood disorder subtype. Our primary hypothesis was that the offspring of parents with BD would be at increased risk for BD and other comorbid disorders common to BD, such as anxiety and substance use, relative to the offspring of parents with MDD. The offspring of parents with BD versus those with MDD were also hypothesized to be at greater risk for externalizing disorders (i.e., conduct disorder, attention-deficit hyperactivity disorder, or antisocial personality disorder). METHODS: Parents (n = 320) with mood disorders and their offspring (n = 679) were studied. Adult offspring were administered the Structured Clinical Interview for DSM-IV Axis I Disorders to establish the presence of psychopathology. Offspring aged 10-18 years were assessed using the School Aged Schedule for Affective Disorders and Schizophrenia, Present and Lifetime version, and parents of children under the age of ten completed the Child Behavioral Checklist. Data were examined using Cox proportional hazard regression. RESULTS: There was no difference in hazard of mood disorders in the offspring of parents with BD as compared to the offspring of parents with MDD. However, a number of other parent and offspring characteristics increased the risk of mood, anxiety, externalizing, and substance use disorders in the offspring, including self-reported childhood abuse in the parent or offspring, offspring impulsive aggression, and the age at onset of parental mood disorder. CONCLUSIONS: Mood disorders are highly familial, a finding that appears independent of whether the parent's condition is unipolar or bipolar, suggesting considerable overlap in the heritability of MDD and BD. Although parental characteristics had a limited influence on the risk of offspring psychopathology, reported childhood adversity, be it in the parent or child, is a harbinger of negative outcomes. These risk factors extend previous findings, and are consistent with diathesis-stress conceptualizations.

Deconstructing resilience in patients at high risk for suicidal behavior.

BACKGROUND: Resilience represents coping abilities to overcome exposure to psychopathological risk. In the context of risk factors for suicidal behavior, it is unknown if this attribute is deficient in suicide attempters, how it relates to other measures of risk, and where it may overlap with other risk factors associated with suicidal behavior. METHODS: The present study examined the performance on the Connor-Davidson Resilience Scale (CD-RISC) in three groups of individuals with familial risk for both mood disorder and suicidal behavior, as well as a healthy comparison group. Other risk factors for suicidal behavior, such as depression severity, hopelessness, and lifetime impulsiveness were examined as well to determine if these mediated group differences in CD-RISC scores. RESULTS: CD-RISC scores differed between groups, with lowest scores in the past attempter group. However, CD-RISC scores were strongly correlated with other common risk factors for suicide attempt, including hopelessness, subjective depression, and reasons for living, which together explained 68 % of the CD-RISC variance. Group differences in CD-RISC scores were eliminated when the model included these covariates. LIMITATIONS: Sample sizes were modest, and depression severity was low overall and significantly higher in the past suicide attempter group. CONCLUSIONS: The CD-RISC has demonstrated utility for predicting risk for depression, but appears to overlap with other known risk factors for suicidal behavior, especially hopelessness and subjective depression. Though it encapsulates variance from multiple risk factors in a single scale, it may not provide additional predictive power above and beyond these other risk factors for suicidal behavior.

Twenty-six years of psychosocial interventions to reduce suicide risk in adolescents: Systematic review and meta-analysis.

BACKGROUND: During adolescence, suicide risk increases; effective treatments are needed to reduce risk. METHODS: Databases were searched (1995-2020) for randomized controlled trials (RCTs) concerning psychosocial treatments for suicide prevention in adolescents (10-18 yrs). Data were extracted from the timepoint closest to 6 months. Cohen's ds were estimated for reducing suicidal ideation (SI), self-harming behaviors (SHB) excluding strictly non-suicidal self-injury, and suicide attempts (SA) and analyzed using generalized least square regression. Meta-analytic innovations included within-person correlations to reflect trait suicidality; annualization to control for exposure; estimated lifetime risk based on ages; and modeling inclusion/exclusion criteria. Alternate approaches included relative risk and comparison of intervention and control treatments to baseline. RESULTS: Of 30 RCTs, 6 assessing SHB (4 measuring SA), and 7 assessing SI demonstrated treatment effectiveness. Overall, interventions decreased SI (n = 25) with low effect size (d = 0.08, p = 0.01), non-significant after controlling for publication bias (d = 0.05, p = 0.1); interventions were non-significant for SHB (n = 25, d = 0.001, p = 0.97) or SA (n = 18, d = 0.03, p = 0.52). To prevent one SHB, the number needed to treat (NNT) was 45[26,156]; for SA, NNT=42[24,149]. Non-superiority may relate to effectiveness of control treatments. Thus, experimental and control treatments also were compared to baseline: both reduced SI (p < 0.0001), and effectiveness improved for SHB (NNT=12) and SA (NNT=11). LIMITATIONS: Study heterogeneity and inconsistent statistical reporting limited meta-analysis. CONCLUSIONS: Psychosocial interventions for suicide risk in adolescents showed little effectiveness compared with control treatments; suicide outcomes improved in both groups compared to baseline. Different approaches may be needed, including precision medicine methodologies and standardized statistical reporting criteria.

Norepinephrine and serotonin imbalance in the locus coeruleus in bipolar disorder.

OBJECTIVES: Abnormalities in norepinephrine (NE) and serotonin (5-HT) are implicated in bipolar disorder (BD). We examined 5-HT input and NE neurons in the locus coeruleus (LC, the NE nucleus that innervates the forebrain) in BD by quantifying immunoreactivity (IR) for tyrosine hydroxylase (TH) and tryptophan hydroxylase (TPH), the biosynthetic enzymes for NE and 5-HT, respectively. METHODS: Six suicides with BD were compared to matched normal controls and unipolar major depression suicides, using immunocytochemistry with computer-assisted quantification of immunoreactivity. RESULTS: Depressed bipolar suicides had 26.7 +/- 1.3% of LC area occupied by the TH immunoreactive (TH-IR) process, while controls had 50.7 +/- 8% (p = 0.002) and unipolar depressed suicides had 50.3 +/- 2.5% (p = 0.003). In bipolars, these processes did not stain as darkly (1.9 +/- 0.5 x background) as controls (2.9 +/- 0.9 x background; p = 0.01) or unipolars (2.9 +/- 0.6 x background; p = 0.002). Bipolar suicides also had less TPH-IR processes in the LC (11.7 +/- 10%) compared with controls (32.8 +/- 8.8%; p = 0.01) or unipolar suicides (30.3 +/- 8%; p = 0.02). The TPH-IR intensity did not differ between groups. CONCLUSIONS: We found less TH-IR and TPH-IR in the LC in depressed bipolar suicides, but not unipolar suicides, suggesting that both NE and 5-HT activity is lower in BD. Studies during manic or euthymic states will determine whether these changes are mood state dependent.

Comorbid anxiety in bipolar disorder: does it have an independent effect on suicidality?

OBJECTIVE: Comorbid anxiety disorder is reported to increase suicidality in bipolar disorder. However, studies of the impact of anxiety disorders on suicidal behavior in mood disorders have shown mixed results. The presence of personality disorders, often comorbid with anxiety and bipolar disorders, may explain these inconsistencies. This study examined the impact of comorbid Cluster B personality disorder and anxiety disorder on suicidality in bipolar disorder. METHODS: A total of 116 depressed bipolar patients with and without lifetime anxiety disorder were compared. Multiple regression analysis tested the association of comorbid anxiety disorder with past suicide attempts and severity of suicidal ideation, adjusting for the effect of Cluster B personality disorder. The specific effect of panic disorder was also explored. RESULTS: Bipolar patients with and without anxiety disorders did not differ in the rate of past suicide attempt. Suicidal ideation was less severe in those with anxiety disorders. In multiple regression analysis, anxiety disorder was not associated with past suicide attempts or with the severity of suicidal ideation, whereas Cluster B personality disorder was associated with both. The results were comparable when comorbid panic disorder was examined. CONCLUSIONS: Comorbid Cluster B personality disorder appears to exert a stronger influence on suicidality than comorbid anxiety disorder in persons with bipolar disorder. Assessment of suicide risk in patients with bipolar disorder should include evaluation and treatment of Cluster B psychopathology.

Suicidal ideation declines with improvement in the subjective symptoms of major depression.

BACKGROUND: Suicidal ideation appears to be more strongly associated with subjective rather than neurovegetative symptoms of depression. Effective treatment, then, should produce reductions in suicidal ideation to the degree that these subjective symptoms are alleviated relative to treatment effects on other symptoms. METHODS: In a randomized clinical trial comparing paroxetine and bupropion for treatment of depression in patients with either suicidal ideation or past attempt, depression severity and suicidal ideation were assessed weekly during the 8-week study. Depression rating scales - the 24-item Hamilton Depression Rating Scale [HDRS] and the Beck Depression Scale [BDI] - were decomposed into symptom clusters based on our published factor analyses, and their change over time compared to changes on the Beck Scale for Suicidal Ideation [SSI]. RESULTS: Improvement in factor scores associated with subjective symptoms of depression - HDRS Psychic Depression, BDI Subjective Depression, and BDI Self-Blame - were the best predictors of declining scores on the SSI regardless of type of drug treatment. BDI Subjective Depression was the best single predictor in the context of all other significant univariate predictors, accounting for 31.4% of the variance in the change in SSI. The three factors together accounted for 35.3%. LIMITATIONS: This is a secondary analysis of clinical trial data, with fixed treatments. CONCLUSIONS: Effective treatments to reduce suicidal ideation are associated with the reduction of the subjective symptoms of depression, which may not always decline in synchrony with improvement in neurovegetative symptoms. This asynchrony may result in a period of elevated risk after the initiation of therapy. Data indicate that subjective depression symptoms should be a primary target in the treatment of depressed suicidal patients.

Effects of anxiety on suicidal ideation: exploratory analysis of a paroxetine versus bupropion randomized trial.

It is unclear whether anxiety increases or decreases suicidal risk. This may contribute to the lack of guidance on which antidepressant medications are best for suicidal depressed patients who present with high anxiety. This study explored whether anxiety predicts suicidal ideation in depressed individuals treated with paroxetine or bupropion. An 8-week double-blind trial comparing controlled-release paroxetine (N=36) versus extended-release bupropion (N=38) for effect on suicidal ideation and behavior in depressed patients with suicidal ideation, past attempt, or both found an advantage for paroxetine, but anxiety effects were not investigated. This secondary analysis explored the relationship, measured at baseline and weekly, of anxiety with suicidal ideation. Anxiety severity measured weekly correlated with suicidal ideation severity irrespective of treatment (P=0.012). Patients with high baseline anxiety showed a trend toward faster reduction of suicidal ideation with paroxetine compared with bupropion treatment (standard P=0.047; bootstrap P=0.077). The latter finding, if confirmed in larger samples, could enhance choice of antidepressant medication for suicidal, depressed patients presenting with high levels of anxiety.

Higher postmortem prefrontal 5-HT2A receptor binding correlates with lifetime aggression in suicide.

BACKGROUND: In vivo studies find altered serotonin function associated with aggressive and suicidal behaviors. Postmortem studies also reveal serotonergic alterations in suicide subjects but have not reported on the relationship between aggression and the serotonin system. We measured 5-hydroxytryptamine 2A (5-HT(2A)) receptor binding in prefrontal cortex of suicide and nonsuicide subjects and explored the relationship between 5-HT(2A) receptor binding, lifetime aggression, and suicide. METHODS: The 5-HT(2A) receptor binding in coronal sections of prefrontal cortex was quantified by autoradiography with [(3)H] ketanserin in 37 suicide subjects and 73 nonsuicide subjects. The relationship between [(3)H] ketanserin binding and lifetime aggression, rated on the Brown-Goodwin Aggression History Scale, was assessed controlling for age and sex. RESULTS: In suicide subjects, lifetime aggression scores correlated positively with [(3)H] ketanserin binding in all prefrontal Brodmann areas examined, after adjusting for age and sex. This was not the case in nonsuicide subjects. We found no significant differences in aggression scores or [(3)H] ketanserin binding between the suicide subjects and nonsuicide subjects. CONCLUSIONS: The relationship between aggression and 5-HT(2A) receptor binding in suicide subjects, but not in nonsuicide subjects, may reflect differences in the regulation of the 5-HT(2A) receptor related to suicidal behavior and perhaps other proaggressive changes in brains of suicide subjects.

Association of a triallelic serotonin transporter gene promoter region (5-HTTLPR) polymorphism with stressful life events and severity of depression.

OBJECTIVE: The lower expressing allele of the serotonin transporter gene 5' promoter region (5-HTTLPR) polymorphism is reported to be associated with susceptibility to depression and suicidality in response to stressful life events. The authors examined the relationship of a triallelic 5-HTTLPR polymorphism to stressful life events, severity of major depression, and suicidality. METHOD: Mood disorder subjects (N=191) and healthy volunteers (N=125), all Caucasian subjects of European origin, were genotyped for the triallelic 5-HTTLPR polymorphism (higher expressing allele: L(A); lower expressing alleles: L(G), S). All subjects underwent structured clinical interviews to determine DSM-IV diagnoses, ratings of psychopathology, stressful life events, developmental history, and suicidal behavior. CSF 5-HIAA was assayed in a subgroup of subjects. RESULTS: Lower expressing alleles independently predicted greater depression severity and predicted greater severity of major depression with moderate to severe life events compared with the higher expressing L(A) allele. No associations with suicidal behavior and CSF 5-HIAA were found. CONCLUSIONS: Lower expressing transporter alleles, directly and by increasing the impact of stressful life events on severity, explain 31% of the variance in major depression severity. The biological phenotype responsible for these effects remains to be elucidated.

Self-Rated Depression Severity Relative to Clinician-Rated Depression Severity: Trait Stability and Potential Role in Familial Transmission of Suicidal Behavior.

Self-rated depression and hopelessness severity are predictors of suicide attempt in major depression. This study evaluated whether: (1) greater self-rated distress relative to severity of clinician-rated depression is a trait; (2) that trait is familial; and (3) that trait is linked to familial transmission of suicidal behavior. A total of 285 mood disorder probands and 457 offspring were assessed twice, at least 1 year apart. Family and subject intra-class correlations for self-report depression and hopelessness, controlling for clinician-rated depression severity, were computed. Mixed general linear models determined offspring-proband correlations. Within-individual intra-class correlation (ICC) for depression-hopelessness was 37.8% (bootstrap 95% CI: 31.0-46.3%). Parent-offspring ICC was 10.7% (bootstrap 95% CI: 3.5-17.8%). Suicide attempt concordant parent-offspring correlation for subjective depression was positive, but negative for attempter parent and nonattempter offspring (p = .0213 for slope interaction). Pessimism was greater in proband or offspring attempters than proband or offspring nonattempters (p < .05). Self-reported hopelessness is partly trait-dependent, and there is modest familial transmission of self-reported depression linked to suicidal behavior that may partly explain familial transmission of suicidal behavior.

Posttraumatic stress disorder comorbid with major depression: factors mediating the association with suicidal behavior.

OBJECTIVE: The purpose of the study was to determine if patients with a history of major depressive episode and comorbid posttraumatic stress disorder (PTSD) have a higher risk for suicide attempt and differ in other measures of suicidal behavior, compared to patients with major depressive episode but no PTSD. In addition, to explore how PTSD comorbidity might increase risk for suicidal behavior in major depressive episode, the authors investigated the relationship between PTSD, cluster B personality disorder, childhood sexual or physical abuse, and aggression/impulsivity. METHOD: The subjects were 230 patients with a lifetime history of major depressive episode; 59 also had lifetime comorbid PTSD. The demographic and clinical characteristics of subjects with and without PTSD were compared. Multivariate analysis was used to examine the relationship between suicidal behavior and lifetime history of PTSD, with adjustment for clinical factors known to be associated with suicidal behavior. RESULTS: Patients with a lifetime history of PTSD were significantly more likely to have made a suicide attempt. The groups did not differ with respect to suicidal ideation or intent, number of attempts made, or maximum lethality of attempts. The PTSD group had higher objective depression, impulsivity, and hostility scores; had a higher rate of comorbid cluster B personality disorder; and were more likely to report a childhood history of abuse. However, cluster B personality disorder was the only independent variable related to lifetime suicide attempts in a multiple regression model. CONCLUSIONS: PTSD is frequently comorbid with major depressive episode, and their co-occurrence enhances the risk for suicidal behavior. A higher rate of comorbid cluster B personality disorder appears to be a salient factor contributing to greater risk for suicidal acts in patients with a history of major depressive episode who also have PTSD, compared to those with major depressive episode alone.

Symptom components of standard depression scales and past suicidal behavior.

BACKGROUND: Global severity on depression scales may obscure associations between specific symptoms and suicidal behavior. METHODS: We studied 298 persons with major depressive disorder. Factor analysis of the 24-item Hamilton Depression Rating Scale (HDRS) and the Beck Depression Inventory (BDI) was used to compare symptom clusters between past suicide attempters and non-attempters. RESULTS: Factor analyses extracted five HDRS and three BDI factors. Suicide attempters had significantly lower scores on an HDRS anxiety factor and higher scores on a BDI self-blame factor. The factor scores correlated with total number of suicide attempts and with known risk factors for suicidal behavior. LIMITATIONS: The differences in factor scores between suicide attempters and non-attempters were significant but modest and may be most relevant in suggesting areas for further clinical studies. Structured diagnostic interviews in this study may have limited the detection of Bipolar II or milder bipolar spectrum disorders. CONCLUSIONS: Depressed suicide attempters exhibit comparably severe mood and neuro-vegetative symptoms, but less anxiety and more intense self-blame than non-attempters. This clinical profile may help guide studies of biological correlates and of treatments to reduce suicide risk.

Sex genes for genomic analysis in human brain: internal controls for comparison of probe level data extraction.

BACKGROUND: Genomic studies of complex tissues pose unique analytical challenges for assessment of data quality, performance of statistical methods used for data extraction, and detection of differentially expressed genes. Ideally, to assess the accuracy of gene expression analysis methods, one needs a set of genes which are known to be differentially expressed in the samples and which can be used as a "gold standard". We introduce the idea of using sex-chromosome genes as an alternative to spiked-in control genes or simulations for assessment of microarray data and analysis methods. RESULTS: Expression of sex-chromosome genes were used as true internal biological controls to compare alternate probe-level data extraction algorithms (Microarray Suite 5.0 [MAS5.0], Model Based Expression Index [MBEI] and Robust Multi-array Average [RMA]), to assess microarray data quality and to establish some statistical guidelines for analyzing large-scale gene expression. These approaches were implemented on a large new dataset of human brain samples. RMA-generated gene expression values were markedly less variable and more reliable than MAS5.0 and MBEI-derived values. A statistical technique controlling the false discovery rate was applied to adjust for multiple testing, as an alternative to the Bonferroni method, and showed no evidence of false negative results. Fourteen probesets, representing nine Y- and two X-chromosome linked genes, displayed significant sex differences in brain prefrontal cortex gene expression. CONCLUSION: In this study, we have demonstrated the use of sex genes as true biological internal controls for genomic analysis of complex tissues, and suggested analytical guidelines for testing alternate oligonucleotide microarray data extraction protocols and for adjusting multiple statistical analysis of differentially expressed genes. Our results also provided evidence for sex differences in gene expression in the brain prefrontal cortex, supporting the notion of a putative direct role of sex-chromosome genes in differentiation and maintenance of sexual dimorphism of the central nervous system. Importantly, these analytical approaches are applicable to all microarray studies that include male and female human or animal subjects.

Protection of human subjects in intervention research for suicidal behavior.

OBJECTIVE: Three domains of ethical conduct outlined in the U.S. Food and Drug Administration's 1998 Belmont Report on protection of human research subjects-respect for persons, beneficence, and justice-have posed specific dilemmas in the design of intervention studies for suicidal behavior. These issues include questions about suicidal patients' capacity to provide informed consent, the risk of some lethal outcomes, the possibility of imminent suicide risk associated with patients' right to discontinue the study treatment, and the need for a higher level of monitoring of suicidal patients. The authors examine these and other issues and discuss ways they can be addressed in research design. METHOD: To illustrate solutions to these bioethical tensions, the authors describe the design of a randomized, controlled trial of pharmacotherapy for suicidal behavior in bipolar disorder. RESULTS: Using surrogate outcome measures, allowing prescription of rescue medications, integrating psychosocial interventions, and providing close clinical monitoring enable researchers to conduct research on suicidal behavior while maximizing adherence to the ethical recommendations outlined in the Belmont Report. Alternative study designs, such as add-on trials, in which the study treatment or placebo is added on to known effective treatment, may also be used in research on suicidal behavior. CONCLUSIONS: It is possible to design a randomized, controlled trial that minimizes the risk of morbidity and mortality for suicidal patients with bipolar disorder, but deliberation is required to address the bioethical tensions that arise.

Instability of symptoms in recurrent major depression: a prospective study.

OBJECTIVE: Recurrent episodes of major depressive disorder are reported to have similar or stable characteristics across episodes. However, symptoms appear to be moderately stable only in consecutive depressive episodes or if episode severity is considered. The authors prospectively studied major depressive episodes occurring within 2 years to determine whether symptoms in the second episode could be predicted on the basis of symptoms in the first. METHOD: Inpatients (N=78) with major depressive disorder were rated with the Hamilton Depression Rating Scale during two separate episodes. Patients had a baseline assessment at index hospitalization and follow-up visits at 3, 12, and 24 months after discharge. Information regarding the presence of a major depressive episode, its duration, and its severity was documented. Baseline and follow-up data were analyzed by using Pearson correlations with and without adjustments for severity of depression. RESULTS: Subtype of depression appeared not to be stable. The most robust, although still weak, correlations across episodes were for anxiety and suicidal behavior. Only modest correlations were identified for a few depressive symptoms. CONCLUSIONS: The lack of robust consistency of symptoms or depressive subtype across episodes is striking given the requirement of five of nine predetermined symptoms for depression, increasing the chances of finding an association. These findings suggest that there is a superfamily of mood disorders with pleomorphic manifestations across major depressive episodes within individual patients with unipolar depression.

Prospective study of clinical predictors of suicidal acts after a major depressive episode in patients with major depressive disorder or bipolar disorder.

OBJECTIVE: The authors investigated the predictive potential of a stress-diathesis model for suicidal behavior based on correlates of past suicidal acts. In this model, suicidal acts are precipitated by stressors such as life events or a major depressive episode in the setting of a propensity for acting on suicidal urges. This diathesis is expressed as the tendency to develop more pessimism in response to a stressor and/or the presence of aggressive/impulsive traits. The predictive potential of the diathesis was tested by determining whether clinical correlates of past suicidal behavior predict suicidal acts during a 2-year follow-up of patients with a major depressive episode. METHOD: Patients with DSM-III-R major depressive disorder or bipolar disorder (N=308) were assessed at presentation for treatment of a major depressive episode. Potential predictors of suicidal acts in the 2 years after study enrollment were identified on the basis of an association with previous suicidal behavior and were tested by using Cox proportional hazards regression analysis. In addition, pessimism and aggression/impulsivity factors were generated, and their predictive ability was tested by using Cox proportional hazards regression analysis. RESULTS: The three most powerful predictors of future suicidal acts were a history of suicide attempt, subjective rating of the severity of depression, and cigarette smoking, each of which had an additive effect on future risk. The pessimism and aggression/impulsivity factors both predicted suicidal acts, and each factor showed an additive effect. CONCLUSIONS: In addition to obtaining a history of suicidal behavior, clinicians may find it useful to assess patients' current level of pessimism, aggressive/impulsive traits, and comorbidity with substance use disorders, including nicotine-related disorders, to help identify patients at risk for suicidal behavior after major depression. Interventions such as aggressive pharmacotherapeutic prophylaxis to prevent relapse or recurrence of depressive symptoms may protect such at-risk individuals from future suicidal behavior.