Effects of adjunctive mifepristone (RU-486) administration on neurocognitive function and symptoms in schizophrenia

HPA Axis in the Pathomechanism of Depression and Schizophrenia: New Therapeutic Strategies Based on Its Participation

The hypothalamic-pituitary-adrenal (HPA) axis is involved in the pathophysiology of many neuropsychiatric disorders. Increased HPA axis activity can be observed during chronic stress, which plays a key role in the pathophysiology of depression. Overactivity of the HPA axis occurs in major depressive disorder (MDD), leading to cognitive dysfunction and reduced mood. There is also a correlation between the HPA axis activation and gut microbiota, which has a significant impact on the development of MDD. It is believed that the gut microbiota can influence the HPA axis function through the activity of cytokines, prostaglandins, or bacterial antigens of various microbial species. The activity of the HPA axis in schizophrenia varies and depends mainly on the severity of the disease. This review summarizes the involvement of the HPA axis in the pathogenesis of neuropsychiatric disorders, focusing on major depression and schizophrenia, and highlights a possible correlation between these conditions. Although many effective antidepressants are available, a large proportion of patients do not respond to initial treatment. This review also discusses new therapeutic strategies that affect the HPA axis, such as glucocorticoid receptor (GR) antagonists, vasopressin V1B receptor antagonists and non-psychoactive CB1 receptor agonists in depression and/or schizophrenia.

Mifepristone enhances the neural efficiency of human visuospatial memory encoding and recall

Glucocorticoid receptor (GR) antagonism is a promising new treatment for cognitive dysfunction in psychiatric disorders but the effects of GR antagonism on cognition related brain activity is poorly understood. This study examines the effects of the GR and progesterone receptor antagonist mifepristone on the neural correlates of visuospatial learning and working memory in healthy male participants. The study used a pharmacological functional magnetic resonance imaging (fMRI) design to determine mifepristone effects on visuospatial paired associates learning (vPAL) and n-back working memory (WM) fMRI task related brain activations. 20 right-handed healthy male participants received 600 mg mifepristone or placebo on two separate imaging days and each participant performed fMRI tasks four hours later. The effect of mifepristone on task related brain activations was determined using Region of Interest (ROI) fMRI analyses and an exploratory whole brain voxel-wise fMRI task analyses was also conducted. The vPAL task ROI analysis found that mifepristone administration was significantly associated with decreased fusiform cortex activations in first and second encoding blocks (p = 0.007, p = 0.04) and decreased angular and precuneal cortices activations in the first recall block (p = 0.01, p = 0.02). There were no significant differences in fMRI brain activations associated with mifepristone administration in the n-back task ROI's (all p > 0.05). Mifepristone administration did not significantly affect fMRI brain activations in the whole brain voxel-wise analyses for both tasks. N-back and vPAL task reaction times and accuracy were similar in both mifepristone and placebo conditions (all p > 0.05). Our finding of decreased fusiform, angular and precuneal vPAL task related brain activity associated with mifepristone administration for the same behavioural performance as found in the placebo condition may represent improved efficiency of visuospatial memory encoding and recall. These findings provide evidence that mifepristone may enhance the efficiency of human visuospatial memory and calls for further studies in patient populations using an fMRI approach to provide proof of concept for new treatments.

11β-hydroxysteroid dehydrogenase type 1 inhibitor use in human disease-a systematic review and narrative synthesis

INTRODUCTION

11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) is an intracellular enzyme that catalyses conversion of cortisone into cortisol; correspondingly, 11β-HSD1 inhibitors inhibit this conversion. This systematic review focuses on the use of 11β-HSD1 inhibitors in diseases known to be associated with abnormalities in hypothalamic pituitary adrenal (HPA) axis function.

METHODS

The databases screened for suitable papers were: MedLine, EMBASE, Web of Science, ClinicalTrials.gov, and Cochrane Central.

RESULTS

1925 papers were identified, of which 29 were included in the final narrative synthesis. 11β-HSD1 and its inhibitors have been studied in diabetes, obesity, metabolic syndrome (MetS), and Alzheimer's disease (AD). Higher expression of 11β-HSD1 is seen in obesity and MetS, but has not yet been described in obesity or AD. Genetic studies identify 11β-HSD1 SNPs of interest in populations with diabetes, MetS, and AD. One phase II trial successfully reduced HbA1c in a diabetic population, however trials in MetS, obesity, and AD have not met primary endpoints.

CONCLUSIONS

Translation of this research from preclinical studies has proved challenging so far, however this is a growing area of research and more studies should focus on understanding the complex relationships between 11β-HSD1 and disease pathology, especially given the therapeutic potential of 11β-HSD1 inhibitors in development.

The past and future of novel, non-dopamine-2 receptor therapeutics for schizophrenia: A critical and comprehensive review

Since the discovery of chlorpromazine in the 1950's, antipsychotic drugs have been the cornerstone of treatment of schizophrenia, and all attenuate dopamine transmission at the dopamine-2 receptor. Drug development for schizophrenia since that time has led to improvements in side effects and tolerability, and limited improvements in efficacy, with the exception of clozapine. However, the reasons for clozapine's greater efficacy remain unclear, despite the great efforts and resources invested therewith. We performed a comprehensive review of the literature to determine the fate of previously tested, non-dopamine-2 receptor experimental treatments. Overall we included 250 studies in the review from the period 1970 to 2017 including treatments with glutamatergic, serotonergic, cholinergic, neuropeptidergic, hormone-based, dopaminergic, metabolic, vitamin/naturopathic, histaminergic, infection/inflammation-based, and miscellaneous mechanisms. Despite there being several promising targets, such as allosteric modulation of the NMDA and α7 nicotinic receptors, we cannot confidently state that any of the mechanistically novel experimental treatments covered in this review are definitely effective for the treatment of schizophrenia and ready for clinical use. We discuss potential reasons for the relative lack of progress in developing non-dopamine-2 receptor treatments for schizophrenia and provide recommendations for future efforts pursuing novel drug development for schizophrenia.

Targeting hypothalamic-pituitary-adrenal axis hormones and sex steroids for improving cognition in major mood disorders and schizophrenia: a systematic review and narrative synthesis

Cognitive deficits are a core feature of serious mental illnesses such as schizophrenia, major depressive disorder (MDD) and bipolar disorder (BD) and are a common cause of functional disability. There is limited efficacy of pharmacological interventions for improving the cognitive deficits in these disorders. As pro-cognitive pharmacological treatments are lacking, hormones or drugs that target the endocrine system may become potential candidates for 'repurposing' trials aiming to improve cognition. We aimed to study whether treatment with drugs targeting the hypothalamic-pituitary-adrenal (HPA) axis and sex steroids can improve cognition in patients with schizophrenia, MDD or BD. A systematic search was performed using PubMed (Medline), PsychInfo and clinicaltrials.gov, and a narrative synthesis was included. The systematic review identified 12 studies dealing with HPA-related drugs (mifepristone [n = 3], cortisol synthesis inhibitors [ketoconazole, n = 2], dehydroepiandrosterone [n = 5], fludrocortisone [n = 2]) and 14 studies dealing with sex steroids (oestradiol [n = 2], selective oestrogen receptor modulators [raloxifene, n = 7], pregnenolone [n = 5]). Positive trials were found for BD (mifepristone), MDD (dehydroepiandrosterone and fludrocortisone) and schizophrenia (dehydroepiandrosterone, raloxifene and pregnenolone). A replication of positive findings by at least two clinical trials was found for mifepristone in BD and raloxifene and pregnenolone in schizophrenia. The use of drugs targeting hormones related to the HPA axis and sex steroids is a promising field of research that might help to improve the cognitive outcome of patients with schizophrenia, bipolar disorder and major depressive disorder in the near future.

Effect of the glucocorticoid receptor antagonist RU486 on MK-801 induced behavioural sensitisation

Stress is known to modulate sensitisation to repeated psychostimulant exposure. However, there is no direct evidence linking glucocorticoids and sensitisation achieved by repeated administration of the NMDA receptor antagonist MK-801. We tested the hypothesis that co-administration of RU486, a glucocorticoid receptor (GR) antagonist, prior to repeated daily MK-801 injections would block the expression of locomotor sensitisation due to its dual effects on corticosterone and dopamine. We employed a repeated MK-801 administration locomotor sensitisation paradigm in male Sprague Dawley rats. RU486 or a dimethyl sulfoxide (DMSO) vehicle was co-administered with MK-801 or saline during the induction phase. Subsequent to withdrawal, rats were challenged with MK-801 alone to test for the expression of sensitisation. In a separate cohort of rats, plasma corticosterone levels were quantified from blood samples taken on the 1^st, 4^th and 7^th day of induction and at expression. One day after challenge, nucleus accumbens tissue levels of dopamine and its metabolites DOPAC and HVA were measured. During the induction phase, RU486 progressively enhanced locomotor sensitisation to MK-801. RU486 and MK-801 both showed stimulatory effects on corticosterone levels and this was further augmented when given in combination. Contrary to our hypothesis, RU486 did not block the expression of locomotor sensitisation to MK-801 and actually increased levels of dopamine, DOPAC and HVA in nucleus accumbens tissue. Our results showed that RU486 has augmentative rather than inhibitory effects on MK-801-induced sensitisation. This study indicates a divergent role for glucocorticoids in sensitisation to MK-801 compared to sensitisation with other psychostimulants.

Antiglucocorticoid and related treatments for psychosis

BACKGROUND

Hypothalamic-pituitary-adrenal (HPA) axis dysregulation has been implicated in the development and relapse of psychotic disorders. Elevated cortisol secretion has been positively linked with symptom severity in people with psychosis. Antiglucocorticoid and related drugs that target the HPA axis may be useful for the treatment of individuals with psychosis.

OBJECTIVES

1. To determine the effects of antiglucocorticoid and related drugs for the treatment of psychosis, when used alone or in combination with antipsychotic medication.2. To determine whether the effects of these medications differs between those in a prodromal phase or first episode of psychosis, and those with more established illness.

SEARCH METHODS

We searched the Cochrane Schizophrenia Group's Trials Register (August 2009 and April 2014).

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing antiglucocorticoid and related drugs compared to placebo (either as a sole treatment or as an adjunct to atypical antipsychotics, typical antipsychotics, antidepressants or other combination treatment) for people with a primary diagnosis of a psychotic disorder, or for individuals at high risk of developing a psychotic disorder.

DATA COLLECTION AND ANALYSIS

Review authors independently selected trials, assessed methodological quality and extracted data. We used a fixed-effect meta-analysis. We calculated risk ratios (RRs) with 95% confidence intervals (CIs) for dichotomous outcomes, and mean differences (MDs) and standardised mean differences (SMDs) with 95% CIs for continuous measures. We assessed risk of bias for included studies and used GRADE (Grading of Recommendations Assessment, Development and Evaluation) to create a 'Summary of findings' table.

MAIN RESULTS

We included 11 studies that randomly assigned 509 people with schizophrenia, schizoaffective disorder or psychotic depression. No trials were conducted in patients at their first episode of psychotic illness and none included populations at high risk for developing psychosis. Our pre-stated outcomes of interest were mental state, global state, general functioning, adverse effects and quality of life.Two trials compared antiglucocorticoid drugs (mifepristone) versus placebo as sole treatment. Limited data from one trial showed no difference in the proportion responding to mifepristone when mental state was assessed immediately post intervention using the Brief Psychiatric Rating Scale (BPRS) (n = 5, 1 RCT, MD -5.20, 95% CI -17.91 to 7.51; very low-quality evidence); depressive symptoms (Hamilton Rating Scale for Depression (HAMD) total) were also similar between groups (n = 5, 1 RCT, MD 1.67, 95% CI -16.44 to 19.78; very low-quality evidence). However, a significant difference favoured treatment at short-term follow-up for global state (30% reduction in total BPRS, n = 221, 1 RCT, RR 0.58, 95% CI 0.38 to 0.89; low-grade quality evidence). This effect was also seen for short-term positive psychotic symptoms (50% reduction in BPRS positive symptom subscale, n = 221, 1 RCT, RR 0.60, 95% CI 0.43 to 0.84; low-grade quality evidence). Participants receiving mifepristone experienced a similar overall number of adverse effects as those receiving placebo (n = 226, 2 RCTs, RR 0.92, 95% CI 0.77 to 1.09; moderate-quality evidence). No data on general functioning or quality of life were available.One trial compared an antiglucocorticoid, dehydroepiandrosterone (DHEA), as an adjunct to atypical antipsychotic treatment to adjunctive placebo. Data for main outcomes of interest were of low quality, and analysis of useable data showed no significant effects of treatment on mental state or adverse effects. Data on global state, general functioning and quality of life were not available.Data from six trials comparing antiglucocorticoid drugs as an adjunct to combination treatment versus adjunctive placebo showed no significant differences between groups in mean endpoint scores for overall psychotic symptoms (n = 171, 6 RCTs, SMD 0.01, 95% CI - 0.29 to 0.32) or positive psychotic symptoms (n = 151, 5 RCTs, SMD -0.07, 95% CI - 0.40 to 0.25). Data from three trials showed no differences between groups in mean endpoint scores for negative symptoms (n = 94, 3 RCTs, MD 2.21, 95% CI -0.14 to 4.55). One study found improvements in global state that were similar between groups (n = 30, 1 RCT, RR 0.58, 95% CI 0.32 to 1.06; very low-quality evidence). In this comparison, pooled results showed that antiglucorticoids caused a greater overall number of adverse events (n = 199, 7 RCTs, RR 2.66, 95% CI 1.33 to 5.32; moderate quality evidence), but no quality of life data were available.

AUTHORS' CONCLUSIONS

Good evidence is insufficient to conclude whether antiglucocorticoid drugs provide effective treatment for psychosis. Some global state findings suggest a favourable effect for mifepristone, and a few overall adverse effect findings favour placebo. Additional large randomised controlled trials are needed to justify findings.

Do common genotypes of FK506 binding protein 5 (FKBP5) moderate the effects of childhood maltreatment on cognition in schizophrenia and healthy controls?

Common variants of the FK506 binding protein 5 (FKBP5) gene are implicated in psychotic and other disorders, via their role in regulating glucocorticoid receptor (GR) receptor sensitivity and effects on the broader function of the HPA system in response to stress. In this study, the effects of four FKBP5 polymorphisms (rs1360780, rs9470080, rs4713902, rs9394309) on IQ and eight other cognitive domains were examined in the context of exposure to childhood maltreatment in 444 cases with schizophrenia and 292 healthy controls (from a total sample of 617 cases and 659 controls obtained from the Australian Schizophrenia Research Bank; ASRB). Participants subjected to any kind of maltreatment (including physical, emotional, or sexual abuse or physical or emotional neglect) in childhood were classified as 'exposed'; cognitive functioning was measured with Repeatable Battery for the Assessment of Neuropsychological Status, the Controlled Oral Word Association Test, and IQ was estimated with the Weschler Test of Adult Reading. Hierarchical regressions were used to test the main effects of genotype and childhood maltreatment, and their additive interactive effects, on cognitive function. For rs1360870, there were significant main effects of genotype and childhood maltreatment, and a significant interaction of genotype with childhood trauma affecting attention in both schizophrenia and healthy participants (C-homozygotes in both groups showed worse attention in the context of maltreatment); in SZ, this SNP also affected global neuropsychological function regardless of exposure to childhood trauma, with T-homozygotes showing worse cognition than other genotypes. The mechanisms of trauma-dependent effects of FKBP5 following early life trauma deserve further exploration in healthy and psychotic samples, in the context of epigenetic effects and perhaps epistasis with other genes. Study of these processes may be particularly informative in subgroups exposed to various other forms of early life adversity (i.e., birth complications, immigration).

Hypothalamic-pituitary-adrenocortical axis: neuropsychiatric aspects

Evidence of aberrant hypothalamic-pituitary-adrenocortical (HPA) activity in many psychiatric disorders, although not universal, has sparked long-standing interest in HPA hormones as biomarkers of disease or treatment response. HPA activity may be chronically elevated in melancholic depression, panic disorder, obsessive-compulsive disorder, and schizophrenia. The HPA axis may be more reactive to stress in social anxiety disorder and autism spectrum disorders. In contrast, HPA activity is more likely to be low in PTSD and atypical depression. Antidepressants are widely considered to inhibit HPA activity, although inhibition is not unanimously reported in the literature. There is evidence, also uneven, that the mood stabilizers lithium and carbamazepine have the potential to augment HPA measures, while benzodiazepines, atypical antipsychotics, and to some extent, typical antipsychotics have the potential to inhibit HPA activity. Currently, the most reliable use of HPA measures in most disorders is to predict the likelihood of relapse, although changes in HPA activity have also been proposed to play a role in the clinical benefits of psychiatric treatments. Greater attention to patient heterogeneity and more consistent approaches to assessing treatment effects on HPA function may solidify the value of HPA measures in predicting treatment response or developing novel strategies to manage psychiatric disease.

Morning cortisol levels in schizophrenia and bipolar disorder: a meta-analysis

Increased peripheral levels of morning cortisol have been reported in people with schizophrenia (SZ) and bipolar disorder (BD), but findings are inconsistent and few studies have conducted direct comparisons of these disorders. We undertook a meta-analysis of studies examining single measures of morning cortisol (before 10 a.m.) levels in SZ or BD, compared to controls, and to each other; we also sought to examine likely moderators of any observed effects by clinical and demographic variables. Included studies were obtained via systematic searches conducted using Medline, BIOSIS Previews and Embase databases, as well as hand searching. The decision to include or exclude studies, data extraction and quality assessment was completed in duplicate by LG, SM and AS. The initial search revealed 1459 records. Subsequently, 914 were excluded on reading the abstract because they did not meet one or more of the inclusion criteria; of the remaining 545 studies screened in full, included studies were 44 comparing SZ with controls, 19 comparing BD with controls, and 7 studies directly comparing schizophrenia with bipolar disorder. Meta-analysis of SZ (N=2613, g=0.387, p=0.001) and BD (N=704, g=0.269, p=0.004) revealed moderate quality evidence of increased morning cortisol levels in each group compared to controls, but no difference between the two disorders (N=392, g=0.038, p=0.738). Subgroup analyses revealed greater effect sizes for schizophrenia samples with an established diagnosis (as opposed to 'first-episode'), those that were free of medication, and those sampled in an inpatient setting (perhaps reflecting an acute illness phase). In BD, greater morning cortisol levels were found in outpatient and non-manic participants (as opposed to those in a manic state), relative to controls. Neither age nor sex affected cortisol levels in any group. However, earlier greater increases in SZ morning cortisol were evident in samples taken before 8 a.m. (relative to those taken after 8 a.m.). Multiple meta-regression showed that medication status was significantly associated with morning cortisol levels in SZ, when the effects of assay method, sampling time and illness stage were held constant. Heightened levels of morning cortisol in SZ and BD suggest long-term pathology of the hypothalamic-pituitary-adrenal (HPA) axis that may reflect a shared process of illness development in line with current stress-vulnerability models.

Stress facilitates late reversal learning using a touchscreen-based visual discrimination procedure in male Long Evans rats

The stress response is essential to the survival of all species as it maintains internal equilibrium and allows organisms to respond to threats in the environment. Most stress research has focused on the detrimental impacts of stress on cognition and behavior. Reversal learning, which requires a change in response strategy based on one dimension of the stimuli, is one type of behavioral flexibility that is facilitated following some brief stress procedures. The current study investigated a potential mechanism underlying this facilitation by blocking glucocorticoid receptors (GRs) during stress. Thirty-seven male Long Evans rats learned to discriminate between two images on a touchscreen, one of which was rewarded. Once a criterion was reached, rats received stress (30 min of restraint stress or no stress) and drug (GR antagonist RU38486 or vehicle) administration prior to each of the first 3 days of reversal learning. We expected that stress would facilitate reversal learning and RU38486 (10 mg/kg) would prevent this facilitation in both early (<50% correct in one session) and late (>50% correct in one session) stages of reversal learning. Results showed that stressed rats performed better than unstressed rats (fewer days for late reversal, fewer correction trials, and fewer errors) in the late but not early stage of reversal learning. RU38486 did not block the facilitation of RL by stress, although it dramatically increased response, but not reward, latencies. These results confirm the facilitation of late reversal by stress in a touchscreen-based operant task in rats and further our understanding of how stress affects higher level cognitive functioning and behavior.

Antiglucocorticoid therapy for older adults with anxiety and co-occurring cognitive dysfunction: results from a pilot study with mifepristone

OBJECTIVES

In older adults with anxiety disorders, chronically elevated cortisol may contribute to cognitive impairment and elevated anxiety. We conducted a pilot study with mifepristone, a glucocorticoid receptor antagonist, as a potential treatment for late-life anxiety disorders and co-occurring cognitive dysfunction.

METHODS

Fifteen individuals 60 years and older with an anxiety disorder plus cognitive dysfunction participated in the 12-week study. In the first week, participants were randomly assigned to mifepristone 300 mg daily or placebo. In the subsequent 3 weeks, all participants received mifepristone 300 mg. Mifepristone was then discontinued, and the participants were reassessed 8 weeks later. We examined the following: (1) cognitive changes; (2) worry symptom severity; (3) safety and tolerability; and (4) salivary cortisol before, during, and after mifepristone exposure.

RESULTS

Overall safety, tolerability, and high retention supported the feasibility of this research. Participants with higher baseline cortisol levels (peak cortisol >6.0 ng/ml, n = 5) showed improvements in memory, executive function, and worry severity after 3-4 weeks of mifepristone with persistent memory and worry improvements 8 weeks after mifepristone discontinuation. Individuals with low-to-normal baseline cortisol (n = 8) showed little to no improvement. As expected, cortisol levels rose during mifepristone exposure and returned to pretreatment levels 8 weeks after mifepristone discontinuation. In the first week of treatment, there were no differences between placebo-treated and mifepristone-treated participants.

CONCLUSION

The results of this pilot study warrant further testing of antiglucocorticoid agents in late-life anxiety disorders with co-occurring cognitive dysfunction. Mifepristone is hypothesized to have benefits in patients with evidence of glucocorticoid excess. Directions for further study are discussed.

Stress, schizophrenia and bipolar disorder

The role of stress in precipitating psychotic episodes in schizophrenia and bipolar disorder has long been acknowledged. However, the neurobiological mechanism/s of this association have remained elusive. Current neurodevelopmental models of psychosis implicate early dysfunction in biological systems regulating hypothalamic-pituitary-adrenal axis and immune function, with long-term effects on the development of the brain networks responsible for higher order cognitive processes and stress reactivity in later life. There is also increasing evidence of childhood trauma in psychosis, and its impact on the development of brain systems regulating stress. These findings are emerging in the context of a new era of epigenetic methods facilitating the study of environmental effects on gene expression. The evidence is thus converging: exposure to stress at critical periods in life may be an important factor in the development of the brain dysfunction that represents psychosis vulnerability, rather than merely interacting with an independent 'biological vulnerability' to manifest in psychosis.

Mind and body: how the health of the body impacts on neuropsychiatry

It has long been established in traditional forms of medicine and in anecdotal knowledge that the health of the body and the mind are inextricably linked. Strong and continually developing evidence now suggests a link between disorders which involve Hypothalamic-Pituitary-Adrenal axis (HPA) dysregulation and the risk of developing psychiatric disease. For instance, adverse or excessive responses to stressful experiences are built into the diagnostic criteria for several psychiatric disorders, including depression and anxiety disorders. Interestingly, peripheral disorders such as metabolic disorders and cardiovascular diseases are also associated with HPA changes. Furthermore, many other systemic disorders associated with a higher incidence of psychiatric disease involve a significant inflammatory component. In fact, inflammatory and endocrine pathways seem to interact in both the periphery and the central nervous system (CNS) to potentiate states of psychiatric dysfunction. This review synthesizes clinical and animal data looking at interactions between peripheral and central factors, developing an understanding at the molecular and cellular level of how processes in the entire body can impact on mental state and psychiatric health.

Pharmacological Interventions for the MATRICS Cognitive Domains in Schizophrenia: What's the Evidence?

Schizophrenia is a disabling, chronic psychiatric disorder with a prevalence rate of 0.5-1% in the general population. Symptoms include positive (e.g., delusions, hallucinations), negative (e.g., blunted affect, social withdrawal), as well as cognitive symptoms (e.g., memory and attention problems). Although 75-85% of patients with schizophrenia report cognitive impairments, the underlying neuropharmacological mechanisms are not well understood and currently no effective treatment is available for these impairments. This has led to the Measurement and Treatment Research to Improve Cognition in Schizophrenia (MATRICS) initiative, which established seven cognitive domains that are fundamentally impaired in schizophrenia. These domains include verbal learning and memory, visual learning and memory, working memory, attention and vigilance, processing speed, reasoning and problem solving, and social cognition. Recently, a growing number of studies have been conducted trying to identify the underlying neuropharmacological mechanisms of cognitive impairments in schizophrenia patients. Specific cognitive impairments seem to arise from different underlying neuropharmacological mechanisms. However, most review articles describe cognition in general and an overview of the mechanisms involved in these seven separate cognitive domains is currently lacking. Therefore, we reviewed the underlying neuropharmacological mechanisms focusing on the domains as established by the MATRICS initiative which are considered most crucial in schizophrenia.

Mifepristone as a therapeutic agent in psychiatry

The hypothalamic-pituitary-adrenal (HPA) axis is the body's main stress-response system, and cortisol is the major adrenal glucocorticoid hormone secreted in human beings. HPA axis activity and cortisol secretion is regulated by a negative feedback system involving glucocorticoid receptors. Dysregulation of the HPA axis and increased cortisol levels have been implicated in mood, psychotic, and other psychiatric disorders. Mifepristone, as a potent antagonist of glucocorticoid receptors, has been studied or is currently being investigated as a potential therapeutic agent for psychotic depression, posttraumatic stress disorder, and alcohol and cocaine dependence, as well as for mitigating the weight gain associated with the use of antipsychotic drugs and for improving cognitive dysfunction in schizophrenia and bipolar disorder. This article will review some of the work in these areas.

The role of the glucocorticoids in developing resilience to stress and addiction

There is emerging evidence that individuals have the capacity to learn to be resilient by developing protective mechanisms that prevent them from the maladaptive effects of stress that can contribute to addiction. The emerging field of the neuroscience of resilience is beginning to uncover the circuits and molecules that protect against stress-related neuropsychiatric diseases, such as addiction. Glucocorticoids (GCs) are important regulators of basal and stress-related homeostasis in all higher organisms and influence a wide array of genes in almost every organ and tissue. GCs, therefore, are ideally situated to either promote or prevent adaptation to stress. In this review, we will focus on the role of GCs in the hypothalamic-pituitary adrenocortical axis and extra-hypothalamic regions in regulating basal and chronic stress responses. GCs interact with a large number of neurotransmitter and neuropeptide systems that are associated with the development of addiction. Additionally, the review will focus on the orexinergic and cholinergic pathways and highlight their role in stress and addiction. GCs play a key role in promoting the development of resilience or susceptibility and represent important pharmacotherapeutic targets that can reduce the impact of a maladapted stress system for the treatment of stress-induced addiction.

Mifepristone in the central nucleus of the amygdala reduces yohimbine stress-induced reinstatement of ethanol-seeking

Chronic ethanol exposure leads to dysregulation of the hypothalamic-pituitary-adrenal axis, leading to changes in glucocorticoid release and function that have been proposed to maintain pathological alcohol consumption and increase vulnerability to relapse during abstinence. The objective of this study was to determine whether mifepristone, a glucocorticoid receptor antagonist, plays a role in ethanol self-administration and reinstatement. Male, Long-Evans rats were trained to self-administer either ethanol or sucrose in daily 30 min operant self-administration sessions using a fixed ratio 3 schedule of reinforcement. Following establishment of stable baseline responding, we examined the effects of mifepristone on maintained responding and yohimbine-induced increases in responding for ethanol and sucrose. Lever responding was extinguished in separate groups of rats and animals were tested for yohimbine-induced reinstatement and corticosterone release. We also investigated the effects of local mifepristone infusions into the central amygdala (CeA) on yohimbine-induced reinstatement of ethanol- and sucrose-seeking. In addition, we infused mifepristone into the basolateral amygdala (BLA) in ethanol-seeking animals as an anatomical control. We show that both systemic and intra-CeA (but not BLA) mifepristone administration suppressed yohimbine-induced reinstatement of ethanol-seeking, while only systemic injections attenuated sucrose-seeking. In contrast, baseline consumption, yohimbine-induced increases in responding, and circulating CORT levels were unaffected. The data indicate that the CeA plays an important role in the effects of mifepristone on yohimbine-induced reinstatement of ethanol-seeking. Mifepristone may be a valuable pharmacotherapeutic strategy for preventing relapse to alcohol use disorders and, as it is FDA approved, may be a candidate for clinical trials in the near future.

A Pilot Study of Mifepristone in Combat-Related PTSD

Background. We obtained pilot data to examine the clinical and neuroendocrine effects of short-term mifepristone treatment in male veterans with PTSD. Methods. Eight male veterans with military-related PTSD completed a randomized, double-blind trial of one week of treatment with mifepristone (600 mg/day) or placebo. The primary clinical outcome measures were improvement in PTSD symptoms and dichotomously defined clinical responder status as measured by the CAPS at one-month follow-up. Additional outcome measures included self-reported measures of PTSD symptom severity, CAPS-2 symptom subscale scores, and morning plasma cortisol and ACTH levels. Results. Mifepristone was associated with significant improvements in total CAPS-2 score. At one-month follow-up, all four veterans in the mifepristone group and one of four veterans in the placebo group achieved clinical response; three of four veterans in the mifepristone group and one of four veterans in the mifepristone group remitted. Mifepristone treatment was associated with acute increases in cortisol and ACTH levels and decreases in cytosolic glucocorticoid receptor number in lymphocytes. Conclusions. Further controlled trials of the effects of mifepristone and their durability are indicated in PTSD. If effective, a short-term pharmacological treatment in PTSD could have myriad uses.

Childhood trauma and cognitive function in first-episode affective and non-affective psychosis

BACKGROUND

A history of childhood trauma is reportedly more prevalent in people suffering from psychosis than in the general population. Childhood trauma has also been linked to cognitive abnormalities in adulthood, and cognitive abnormalities, in turn, are one of the key clinical features of psychosis. Therefore, this study investigated whether there was a relationship between childhood trauma and cognitive function in patients with first-episode psychosis. The potential impact of diagnosis (schizophrenia or affective psychosis) and gender on this association was also examined.

METHODS

Data were available for 138 first-episode psychosis patients and 138 geographically-matched controls recruited from a catchment area based organisation. History of childhood trauma was obtained using the Childhood Experience of Care and Abuse Questionnaire. Cognitive function was assessed through a comprehensive and standardised neuropsychological test battery.

RESULTS

A history of childhood trauma was associated with worse cognitive performances, predominantly in affective psychoses, and in male patients. No association between a history of childhood trauma and cognition was found amongst female patients, or female controls.

CONCLUSIONS

The results need replication, but underline the necessity of investigating biological and psychosocial mechanisms underlying these subjects' sensitivity to the negative effect of childhood stress.

Longitudinal changes in cortisol secretion and conversion to psychosis in at-risk youth

Elevations in hypothalamic-pituitary-adrenal (HPA) axis activity have been implicated in the origins and exacerbation of mental disorders. Several lines of investigation suggest HPA activity, indexed by increased cortisol, is elevated in patients with schizophrenia and other psychotic disorders. This study examined the relation of cortisol levels and longitudinal changes with psychotic outcomes in at-risk adolescents. Participants were 56 adolescents who met risk criteria for psychosis, namely, schizotypal personality disorder (n = 5), prodromal symptom criteria based on the Structured Interview for Prodromal Symptoms (n = 17), or both (n = 34). Of these, 14 subsequently met DSM-IV criteria for an Axis I psychotic disorder (schizophrenia, schizoaffective disorder, or mood disorder with psychotic features). Participants were assessed at baseline and then followed longitudinally. Salivary cortisol was sampled multiple times at initial assessment, interim follow-up, and 1-year follow-up. Area under the curve (AUC) was computed from the repeated cortisol measures. The findings indicate that at-risk subjects who subsequently developed psychosis showed significantly higher cortisol at the first follow-up, a trend at the 1-year follow-up, and a significantly larger AUC when compared to those who did not convert. A similar pattern of group differences emerged from analyses excluding those who may have converted prior to the 1-year follow-up. These findings converge with previous reports on HPA activity in psychosis, as well as theoretical assumptions concerning the effects of cortisol elevations on brain systems involved in psychotic symptoms. Future research with larger samples is needed to confirm and extend these results.

A new nosology of psychosis and the pharmacological basis of affective and negative symptom dimensions in schizophrenia

Although first rank symptoms focus on positive symptoms of psychosis they are shared by a number of psychiatric conditions. The difficulty in differentiating bipolar disorder from schizophrenia with affective features has led to a third category of patients often loosely labeled as schizoaffective. Research in schizophrenia has attempted to render the presence or absence of negative symptoms and their relation to etiology and prognosis more explicit. A dichotomous population is a recurring theme in experimental paradigms. Thus, schizophrenia is defined as process or reactive, deficit or non-deficit and by the presence or absence of affective symptoms. Laboratory tests confirm the clinical impression showing conflicting responses to dexamethasone suppression and clearly defined differences in autonomic responsiveness, but their patho-physiological significance eludes mainstream theory. Added to this is the difficulty in agreeing to what exactly constitutes useful clinical features differentiating, for example, negative symptoms of a true deficit syndrome from features of depression. Two recent papers proposed that the general and specific cognitive features of schizophrenia and major depression result from a monoamine-cholinergic imbalance, the former due to a relative muscarinic receptor hypofunction and the latter, in contrast, to a muscarinic hypersensitivity exacerbated by monoamine depletion. Further development of these ideas will provide pharmacological principles for what is currently an incomplete and largely, descriptive nosology of psychosis. It will propose a dimensional view of affective and negative symptoms based on relative muscarinic integrity and is supported by several exciting intracellular signaling and gene expression studies. Bipolar disorder manifests both muscarinic and dopaminergic hypersensitivity. The greater the imbalance between these two receptor signaling systems, the more the clinical picture will resemble schizophrenia with bizarre, incongruent delusions and increasingly disorganized thought. The capacity for affective expression, by definition a non-deficit syndrome, will remain contingent on the degree of preservation of muscarinic signaling, which itself may be unstable and vary between trait and state examinations. At the extreme end of muscarinic impairment, a deficit schizophrenia subpopulation is proposed with a primary and fixed muscarinic receptor hypofunction.

The genomic profile of bipolar disorder and schizophrenia overlap and both have a common dopaminergic intracellular signaling which is hypersensitive to various stressors. It is proposed that the concomitant muscarinic receptor upregulation differentiates the syndromes, being marked in bipolar disorder and rather less so in schizophrenia. From a behavioral point of view non-deficit syndromes and bipolar disorder appear most proximate and could be reclassified as a spectrum of affective psychosis or schizoaffective disorders. Because of a profound malfunction of the muscarinic receptor, the deficit subgroup cannot express a comparable stress response. Nonetheless, a convergent principle of psychotic features across psychiatric disorders is a relative monoaminergic-muscarinic imbalance in signal transduction.

Pharmacological strategies for enhancing cognition in schizophrenia

Researchers have long recognized that individuals with schizophrenia experience challenges in a wide range of cognitive domains, and research on cognitive impairment in schizophrenia is not a recent phenomena. However, the past 10-20 years have seen an increasing recognition of the central importance of cognition to understanding function and outcome in this illness (Green et al. in Schizophr Bull 26:119-136, 2000), an awareness that has shifted the emphasis of at least some work on schizophrenia. More specifically, there has been a rapidly growing body of work on methods of enhancing cognition in schizophrenia, as a means to potentially facilitate improved outcome and quality of life for individuals with this debilitating illness. The current chapter reviews the results of a range of studies examining adjunctive pharmacological treatments to enhance cognition in schizophrenia using a range of designs, including single-dose studies, open-label repeated dosing studies, and double-blind parallel group and crossover designs with repeated dosing. Although many of the single-dose and open-label studies have suggested positive cognitive effects from a range of agents, few of the larger-scale double-blind studies have generated positive results. The current state of results may reflect the need to identify alternative molecular mechanisms for enhancing cognition in schizophrenia or the need to reconceptualize the ways in which pharmacological agents may improve cognition in this illness, with a concomitant change in the traditional clinical trial study design used in prior studies of cognitive enhancement in schizophrenia.

Neuropsychological functioning in health and mood disorder: Modulation by glucocorticoids and their receptors

Numerous studies have shown that disturbances in hypothalamic-pituitary-adrenal (HPA) axis function and consequent hypercortisolaemia occur in a significant proportion of patients with mood disorders. This dysfunction has been proposed to be an exacerbating factor of depressive symptoms and may predict symptomatic relapse. Glucocorticoids are also known to have a specific role in learning and memory processes. In this review we present a brief overview of the relationship between HPA axis dysfunction and neuropsychological impairment in mood disorders and the specific links between glucocorticoids and cognition in health and illness states. Finally we examine the neuropsychological effects of drugs that specifically target glucocorticoid receptor function.

Identification of the functional domain of glucocorticoid receptor involved in RU486 antagonism

Mifepristone, also known as RU486, is a potent glucocorticoid receptor (GR) antagonist that inhibits GR-mediated transactivation. As an alternative to existing antidepressants, RU486 has been shown to rapidly reverse psychotic depression, most likely by blocking GR. Although a number of studies have demonstrated RU486-induced GR antagonism, the precise mechanism of action still remains unclear. To identify the GR domain involved in RU486-induced suppression, GR transactivation and nuclear translocation were examined using cells transfected with human GR (hGR), Guyanese squirrel monkey GR (gsmGR), and GR chimeras into COS-1 cells. RU486 showed a much more potent suppressive effect in gsmGR-expressing cells versus hGR-expressing cells, without significant cortisol- or RU486-induced changes in nuclear translocation. A GR chimera containing the gsmGR AF1 domain (amino acids 132-428) showed a marked decrease in luciferase activity, suggesting that this domain plays an important role in RU486-induced GR antagonism. Furthermore, fluorescence recovery after photobleaching (FRAP) analysis indicated that, in the presence of RU486, gsmGR AF1 domain contributes to GR mobility in living COS-1 cells. Taken together, these results demonstrate, for the first time, that the antagonistic effects of RU486 on GR transactivation involve a specific GR domain.

Preclinical assessment for selectively disrupting a traumatic memory via postretrieval inhibition of glucocorticoid receptors

BACKGROUND

Traumatic experiences may lead to debilitating psychiatric disorders including acute stress disorder and posttraumatic stress disorder. Current treatments for these conditions are largely ineffective, and novel therapies are needed. A cardinal symptom of these pathologies is the reexperiencing of the trauma through intrusive memories and nightmares. Studies in animal models indicate that memories can be weakened by interfering with the postretrieval restabilization process known as memory reconsolidation. We previously reported that, in rats, intraamygdala injection of the glucocorticoid receptor antagonist RU38486 disrupts the reconsolidation of a traumatic memory. Here we tested parameters important for designing novel clinical protocols targeting the reconsolidation of a traumatic memory with RU38486.

METHODS

Using rat inhibitory avoidance, we tested the efficacy of postretrieval systemic administration of RU38486 on subsequent memory retention and evaluated several key preclinical parameters.

RESULTS

Systemic administration of RU38486 before or after retrieval persistently weakens inhibitory avoidance memory retention in a dose-dependent manner, and memory does not reemerge following a footshock reminder. The efficacy of treatment is a function of the intensity of the initial trauma, and intense traumatic memories can be disrupted by changing the time and number of interventions. Furthermore, one or two treatments are sufficient to disrupt the memory maximally. The treatment selectively targets the reactivated memory without interfering with the retention of another nonreactivated memory.

CONCLUSIONS

RU38486 is a potential novel treatment for psychiatric disorders linked to traumatic memories. Our data provide the parameters for designing promising clinical trials for the treatment of flashback-type symptoms of PTSD.

Persistent effects of mifepristone (RU-486) on cortisol levels in bipolar disorder and schizophrenia

Recent pre-clinical and clinical studies have examined the potential use of anti-glucocorticoid drug augmentation - including glucocorticoid receptor (GR) antagonists - as a method of improving treatment response in severe psychiatric illness. However, the direct and persistent effects such drugs exert on the hypothalamic-pituitary-adrenal (HPA) axis are unclear. We examined afternoon cortisol levels in 39 patients (19 with bipolar disorder, 20 with schizophrenia) at baseline, following treatment with mifepristone (600mg/day for 7 days) or placebo and at +21 days. Following treatment with mifepristone (day +7) there was a significant increase in cortisol levels from baseline (mean change=60,434nmol/Lxmin, 95%CI=44,755-76,112; t=7.803, df=38, p<0.0001) which significantly decreased from this point by day +21 (mean change=-64,487nmol/Lxmin, 95%CI=-49,974 to -79,001; t=8.995, df=38, p<0.0001). Cortisol levels at day +21 were significantly lower than they were at baseline (mean change=-4054nmol/Lxmin, 95%CI=-456 to -7652; t=2.281, df=38, p=0.028). No significant changes occurred following placebo. These results provide preliminary evidence that subtle but significant reductions in HPA axis activity (measured by peripheral cortisol levels) are evident 14 days after cessation of treatment with the GR-antagonist mifepristone. This may in part underlie the putative therapeutic effects of such drugs.

Glucocorticoid antagonists in neuropsychiatric [corrected] disorders

Neuropsychiatric disorders often involve considerable psychological stress and elevated cortisol activity. Glucocorticoid receptors have relatively low affinity for cortisol and are found distributed throughout the brain, particularly in the frontal cortex and hippocampus. In recent years, glucocorticoid receptors antagonists have been actively studied in both animal models of several disorders as well as a potential treatment in specific types of neuropsychiatric patients. Data from these various studies are reviewed with an emphasis on seven clinical disorders or problems: major depression with psychotic features, bipolar disorder, schizophrenia, cognitive disorders, (e.g., Alzheimer's disease and mild cognitive impairment), cognitive side effects of electroconvulsive therapy, and weight gain with atypical antipsychotic agents. Potential benefits and limitations are discussed.

Innovative approaches for the treatment of depression: targeting the HPA axis

Altered activity of the hypothalamic pituitary adrenal (HPA) axis is one of the most commonly observed neuroendocrine abnormalities in patients suffering from major depressive disorder (MDD). Altered cortisol secretion can be found in as many as 80% of depressed patients. This observation has led to intensive clinical and preclinical research aiming to better understand the molecular mechanisms which underlie the alteration of the HPA axis responsiveness in depressive illness. Dysfunctional glucocorticoid receptor (GR) mediated negative feedback regulation of cortisol levels and changes in arginine vasopressin (AVP)/vasopressin V1b receptor and corticotrophin-releasing factor/CRF1 receptor regulation of adrenocotricotrophin (ACTH) release have all been implicated in over-activity of the HPA axis. Agents that intervene with the mechanisms involved in (dys)regulation of cortisol synthesis and release are under investigation as possible therapeutic agents. The current status of some of these approaches is described in this review.

Changes in brain-derived neurotrophic factor following treatment with mifepristone in bipolar disorder and schizophrenia

OBJECTIVE

Brain-derived neurotrophic factor (BDNF) is stress-responsive and has been implicated in a number of disparate neuropsychiatric disorders. Glucocorticoid antagonists have been shown to have beneficial effects on mood and cognitive function in bipolar disorder but not in schizophrenia. The aim of the present study was to investigate BDNF levels in patients with bipolar disorder and schizophrenia before and after treatment with the glucocorticoid receptor antagonist mifepristone.

METHODS

Peripheral BDNF levels were measured in patients with bipolar disorder (n=20), schizophrenia (n=20) and 14 matched healthy controls following 7 days of adjunctive mifepristone (600 mg day(-1)) treatment in a double-blind, placebo-controlled crossover design study.

RESULTS

Baseline BDNF values were similar in both patient groups and in healthy controls. Following treatment with mifepristone, cortisol levels were significantly increased and BDNF levels decreased in both schizophrenia and bipolar disorder. A significant correlation existed between change in cortisol level and change in BDNF levels following mifepristone treatment in schizophrenia, but not in bipolar disorder.

CONCLUSION

Differing BDNF responses to increasing cortisol levels between patients with schizophrenia and with bipolar disorder may reflect underlying pathophysiological mechanisms.

Analysis of clinical symptomatology, extrapyramidal symptoms and neurocognitive dysfunction following dehydroepiandrosterone (DHEA) administration in olanzapine treated schizophrenia patients: a randomized, double-blind placebo controlled trial

Several studies have demonstrated the effective use of dehydroepiandrosterone (DHEA) in the management of mood, however studies of its use in psychosis remain limited. The aim of this study was to investigate for the first time efficacy of DHEA augmentation with standardized antipsychotic medication (olanzapine) and to explore effects of DHEA augmentation on side-effect profiles including weight gain, glucose tolerance, aggression, quality of life and neurocognitive function. Finally, we aimed to analyze any relationship between plasma levels and clinical response to DHEA administration. Forty patients with chronic schizophrenia stabilized on olanzapine were randomized in double-blind fashion to receive either DHEA (titrated up to 150mg) or placebo augmentation for a period of 12-weeks. Blood samples were collected at baseline, mid-study and study completion. Results indicated improvement of negative symptoms (SANS scale) even when baseline scores were controlled as a covariate. Some improvement in Parkinsonism and akathisia compared to baseline was seen in patients receiving DHEA. No change in psychosis as reflected by the PANSS was noted. Patients receiving DHEA appeared to demonstrate relatively stable glucose levels compared to controls at the end of the study. An improvement in cognitive performance (most notably memory), which did not reach significance due to low sample number, was observed following DHEA administration. Results further suggest preliminary evidence of involvement of the neurosteroid system in schizophrenia pathophysiology, and confirm initial "cautious" findings identifying an agent capable of improving negative symptoms and certain features of extrapyramidal side effects.

Diminished glucocorticoid negative feedback in polydipsic hyponatremic schizophrenic patients

CONTEXT

The mechanism and significance of diminished glucocorticoid negative feedback in schizophrenia is unknown but is more commonly observed in schizophrenic patients with primary polydipsia. Polydipsic patients, especially those who are also hyponatremic, exhibit other neuroendocrine abnormalities that have been linked to hippocampal pathology.

OBJECTIVE

The objective of the study was to determine the effect of cortisol on plasma ACTH under conditions thought to be most sensitive to hippocampal influences.

DESIGN

The design was repeated measures.

SETTING

The study was conducted at an inpatient clinical research center.

PARTICIPANTS

Participants included eight polydipsic hyponatremic and eight polydipsic normonatremic as well as six schizophrenic patients without water imbalance. Eight healthy community volunteers matched for age and gender were also studied.

INTERVENTION

Metyrapone (750 mg) was administered orally at 1430 and 1900 h. Beginning at 1930 h, hydrocortisone was infused over 150 min at 0.03 mg/kg.h. Blood samples and other measures were obtained at 20-min intervals from 1850 to 2320 h.

MAIN OUTCOME MEASURES

Plasma ACTH and cortisol were measured.

RESULTS

ACTH levels did not decline significantly during the cortisol infusion in the polydipsic hyponatremic group. For any given level of cortisol, ACTH levels were higher in the hyponatremic group. Although levels declined after cortisol in the other three groups, the decline was greatest in patients without water imbalance.

CONCLUSIONS

The marked impairment in glucocorticoid negative feedback in polydipsic hyponatremic schizophrenic patients is consistent with hippocampal mineralocorticoid dysfunction.

Stress, the hippocampus and the hypothalamic-pituitary-adrenal axis: implications for the development of psychotic disorders

OBJECTIVE

The experience of stress is commonly implicated in models of the onset of psychotic disorders. However, prospective studies investigating associations between biological markers of stress and the emergence of psychotic disorders are limited and inconclusive. One biological system proposed as the link between the psychological experience of stress and the development of psychosis is the Hypothalamic-Pituitary-Adrenal (HPA) axis. This paper summarizes and discusses evidence supporting a role for HPA-axis dysfunction in the early phase of schizophrenia and related disorders.

METHOD

A selective review of psychiatric and psychological research on stress, coping, HPA-axis, the hippocampus and psychotic disorders was performed, with a particular focus on the relationship between HPA-axis dysfunction and the onset of psychotic disorders.

RESULTS

Individual strands of past research have suggested that the HPA-axis is dysfunctional in at least some individuals with established psychotic disorders; that the hippocampus is an area of the brain that appears to be implicated in the onset and maintenance of psychotic disorders; and that an increase in the experience of stress precedes the onset of a psychotic episode in some individuals. Models of the onset and maintenance of psychotic disorders that link these individual strands of research and strategies for examining these models are proposed in this paper.

CONCLUSIONS

The current literature provides some evidence that the onset of psychotic disorders may be associated with a higher rate of stress and changes to the hippocampus. It is suggested that future research should investigate whether a relationship exists between psychological stress, HPA-axis functioning and the hippocampus in the onset of these disorders. Longitudinal assessment of these factors in young people at 'ultra' high risk of psychosis and first-episode psychosis cohorts may enhance understanding of the possible interaction between them in the early phases of illness.

Targeting 11β-hydroxysteroid dehydrogenase type 1 in brain: therapy for cognitive aging?

Dementia care costs exceed those of cardiovascular diseases and cancer combined. Milder forms of functionally significant cognitive decline add further to the staggering human, societal and economic costs. However, the underlying mechanisms are poorly understood and few treatments are available. Cumulative exposure to high glucocorticoid levels is a major hypothesis of decline in cognitive function with aging. Current manipulations to maintain low circulating glucocorticoid levels throughout life (adrenalectomy with low-dose corticosterone replacement and neonatal handling), although effective in preventing the emergence of memory deficits with age in rodent models, are not clinically applicable. By contrast, recent data in cells, mice and humans suggest that inhibition of the tissue-selective glucocorticoid-amplifying enzyme, 11β-hydroxysteroid dehydrogenase type 1, may be an effective novel approach.

Cellular plasticity cascades: targets for the development of novel therapeutics for bipolar disorder

For a number of patients with bipolar disorder, current pharmacotherapy is generally insufficient. Despite adequate treatment, patients continue to have recurrent mood episodes, residual symptoms, functional impairment, psychosocial disability, and significant medical and psychiatric comorbidity. Drug development for bipolar disorder may occur through one of two approaches: the first is by understanding the therapeutically relevant biochemical targets of currently effective medications. Two promising direct targets of lithium and valproate are glycogen synthase kinase-3 and histone deacetylase. The second path results from our understanding that severe mood disorders, although not classical neurodegenerative disorders, are associated with regional impairments of structural plasticity and cellular resilience. This suggests that effective treatments will need to provide both trophic and neurochemical support, which serves to enhance and maintain normal synaptic connectivity, thereby allowing the chemical signal to reinstate the optimal functioning of critical circuits necessary for normal affective functioning. For many refractory patients, drugs mimicking "traditional" strategies, which directly or indirectly alter monoaminergic levels, may be of limited benefit. Newer "plasticity enhancing" strategies that may have utility in the treatment of mood disorders include inhibitors of glutamate release, N-methyl-D-aspartate antagonists, alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid potentiators, cyclic adenosine monophosphate phosphodiesterase inhibitors, and glucocorticoid receptor antagonists.

Antiglucocoticoid treatments for depression

OBJECTIVE

To selectively review the literature germane to antiglucocoticoid treatments for depression.

METHOD

Selective review of the relevant literature.

RESULTS

Dysfunction of the hypothalamic-pituitary-adrenal (HPA) axis has been well-described in both bipolar and unipolar depression. Hypercortisolaemia, possibly secondary to breakdown in glucocorticoid-receptor-mediated negative feedback mechanisms within the HPA axis, may be central to the pathogenesis of both depressive symptoms and the neurocognitive deficits which characterize these disorders. Strategies to counteract the effects of elevated cortisol, which may potentially restore HPA axis integrity, have been the focus of recent research.

CONCLUSIONS

Both preclinical and clinical studies report encouraging results which suggest that lowering circulating cortisol levels or blocking the effects of elevated cortisol with antagonists, which may up-regulate glucocorticoid receptors, has therapeutic benefits in terms of improvements in depressive symptoms and some domains of neurocognitive function.

The use of mifepristone in the treatment of neuropsychiatric disorders

Mifepristone is a potent glucocorticoid and progesterone receptor antagonist. The pathophysiology of a number of neuropsychiatric disorders implicates abnormalities in glucocorticoid function. These include mood disorders such as psychotic major depression and bipolar depression. In addition, cognitive disorders such as Alzheimer's disease might also be partially mediated by abnormalities in the hypothalamic-pituitary-adrenal axis. Preliminary studies suggest that mifepristone might have a role in the treatment of a number of neuropsychiatric disorders.

Pituitary volume predicts future transition to psychosis in individuals at ultra-high risk of developing psychosis

BACKGROUND

We examined pituitary volume before the onset of psychosis in subjects who were at ultra-high risk (UHR) for developing psychosis.

METHODS

Pituitary volume was measured on 1.5-mm, coronal, 1.5-T magnetic resonance images in 94 UHR subjects recruited from admissions to the Personal Assessment and Crisis Evaluation Clinic in Melbourne, Australia and in 49 healthy control subjects. The UHR subjects were scanned at baseline and were followed clinically for a minimum of 1 year to detect transition to psychosis.

RESULTS

Within the UHR group, a larger baseline pituitary volume was a significant predictor of future transition to psychosis. The UHR subjects who later went on to develop psychosis (UHR-P, n = 31) had a significantly larger (+12%; p = .001) baseline pituitary volume compared with UHR subjects who did not go on to develop psychosis (UHR-NP, n = 63). The survival analysis conducted by Cox regression showed that the risk of developing psychosis during the follow-up increased by 20% for every 10% increase in baseline pituitary volume (p = .002). Baseline pituitary volume of the UHR-NP subjects was smaller not only compared with UHR-P (as described above) but also compared with control subjects (-6%; p = .032).

CONCLUSIONS

The phase before the onset of psychosis is associated with a larger pituitary volume, suggesting activation of the HPA axis.

Cortisol in mood disorders

Dysfunction of the hypothalamic-pituitary-adrenal (HPA) axis has been well-described in mood disorders. Hypercortisolaemia, which has been attributed to a breakdown in glucocorticoid-receptor-mediated negative feedback mechanisms within the HPA axis, may be central to the pathogenesis of both the depressive symptoms and the cognitive deficits, which characterise severe mood disorders. Strategies to normalise glucocorticoid receptor (GR) function, and thus restore HPA functional integrity, have been the focus of recent research. Preliminary preclinical and clinical studies report encouraging results which suggest that lowering circulating cortisol levels, by up-regulating GRs, may have therapeutic efficacy in terms of improvements in depressive symptoms and cognitive functioning.