Potential Role of Oestrogen Modulation in the Treatment of Neurocognitive Deficits in Schizophrenia

Durability of Effects of Cognitive Remediation on Cognition and Psychosocial Functioning in Schizophrenia: A Systematic Review and Meta-Analysis of Randomized Clinical Trials

OBJECTIVE

Cognitive remediation provides substantial improvements in cognitive performance and real-world functioning for people living with schizophrenia, but the durability of these benefits needs to be reassessed and better defined. The aims of this study were to provide a comprehensive assessment of the durability of the benefits of cognitive remediation for cognition and functioning in people living with schizophrenia and evaluating potential moderators of effects.

METHODS

A systematic search was conducted in PubMed, Scopus, and PsycINFO, and reference lists of included articles and Google Scholar were inspected. Eligible studies were randomized clinical trials of cognitive remediation in patients diagnosed with schizophrenia spectrum disorders in which follow-up assessments were included. Screening and data extraction were performed by at least two independent reviewers. Cohen's d was used to measure outcomes. Primary outcomes were changes in cognition and functioning from baseline to conclusion of follow-up. Moderators of the durability of effects were assessed.

RESULTS

Of 2,840 identified reports, 281 full texts were assessed and 130 reports on 67 studies with 5,334 participants were included. Cognitive remediation produced statistically significant positive effects that persisted at the end of follow-up in global cognition (d=0.23) and in global functioning (d=0.26). Smaller study samples and single-center studies were associated with better cognitive outcomes; longer treatment and follow-up duration, techniques for transferring cognitive gains to the real world, integration with psychiatric rehabilitation, group format of delivery, and more female participants in the sample were associated with better functional outcomes.

CONCLUSIONS

Cognitive remediation provides durable improvements in cognition and functioning in schizophrenia. This finding corroborates the notion that cognitive remediation should be implemented more widely in clinical and rehabilitation practice.

Role of estrogen in sex differences in memory, emotion and neuropsychiatric disorders

Estrogen regulates a wide range of neuronal functions in the brain, such as dendritic spine formation, remodeling of synaptic plasticity, cognition, neurotransmission, and neurodevelopment. Estrogen interacts with intracellular estrogen receptors (ERs) and membrane-bound ERs to produce its effect via genomic and non-genomic pathways. Any alterations in these pathways affect the number, size, and shape of dendritic spines in neurons associated with psychiatric diseases. Increasing evidence suggests that estrogen fluctuation causes changes in dendritic spine density, morphology, and synapse numbers of excitatory and inhibitory neurons differently in males and females. In this review, we discuss the role of estrogen hormone in rodents and humans based on sex differences. First, we explain estrogen role in learning and memory and show that a high estrogen level alleviates the deficits in learning and memory. Secondly, we point out that estrogen produces a striking difference in emotional memories in men and women, which leads them to display sex-specific differences in underlying neuronal signaling. Lastly, we discuss that fluctuations in estrogen levels in men and women are related to neuropsychiatric disorders, including schizophrenia, autism spectrum disorder (ASD), attention deficit hyperactivity disorder (ADHD), bipolar disorder (BPD), major depressive disorder (MDD), substance use disorder (SUD), and anxiety disorders.

Adolescent raloxifene treatment in females prevents cognitive deficits in a neurodevelopmental rodent model of schizophrenia

The existence of sex differences in schizophrenia is a well documented phenomenon which led to the hypothesis that female sex hormones are neuroprotective and hence responsible for the more favorable disease characteristics seen in women. The current study sought to investigate the effects of estrogen-like agents administered during early adolescence on behavioral outcomes in adulthood using the neurodevelopmental maternal immune activation (MIA) rodent model of schizophrenia. Female MIA offspring were administered during the asymptomatic period of adolescence with either 17β-estradiol, raloxifene or saline and were tested in late adolescence and adulthood for schizophrenia-related behavioral performance. We report here that whereas adult female MIA offspring exhibited cognitive deficits in the form of retarded spatial learning, the administration of raloxifene during adolescence was sufficient in preventing these deficits and resulted in intact performance in the MIA group.

Estradiol reverses excitatory synapse loss in a cellular model of neuropsychiatric disorders

Loss of glutamatergic synapses is thought to be a key cellular pathology associated with neuropsychiatric disorders including schizophrenia (SCZ) and major depressive disorder (MDD). Genetic and cellular studies of SCZ and MDD using in vivo and in vitro systems have supported a key role for dysfunction of excitatory synapses in the pathophysiology of these disorders. Recent clinical studies have demonstrated that the estrogen, 17β-estradiol can ameliorate many of the symptoms experienced by patients. Yet, to date, our understanding of how 17β-estradiol exerted these beneficial effects is limited. In this study, we have tested the hypothesis that 17β-estradiol can restore dendritic spine number in a cellular model that recapitulates the loss of synapses associated with SCZ and MDD. Ectopic expression of wildtype, mutant or shRNA-mediated knockdown of Disrupted in Schizophrenia 1 (DISC1) reduced dendritic spine density in primary cortical neurons. Acute or chronic treatment with 17β-estradiol increased spine density to control levels in neurons with altered DISC1 levels. In addition, 17β-estradiol reduced the extent to which ectopic wildtype and mutant DISC1 aggregated. Furthermore, 17β-estradiol also caused the enrichment of synaptic proteins at synapses and increased the number of dendritic spines containing PSD-95 or that overlapped with the pre-synaptic marker bassoon. Taken together, our data indicates that estrogens can restore lost excitatory synapses caused by altered DISC1 expression, potentially through the trafficking of DISC1 and its interacting partners. These data highlight the possibility that estrogens exert their beneficial effects in SCZ and MDD in part by modulating dendritic spine number.

Schizophrenia and Sex Hormones: What Is the Link?

The involvement of gonadal hormones in the pathogenesis of schizophrenia has long been suspected because the psychosis differs in women and men and the illness first makes its appearance shortly after puberty. Changes in sex hormones have been linked with increased vulnerability to mood disorders in women, while testosterone have been associated with increased sexual drive and aggressiveness in men as well as women. Some studies have found abnormal levels of estrogens and testosterone in schizophrenia patients, but the results have been inconsistent and sometimes attributed to the hyperprolactinemia effect of antipsychotics, which may interfere with sex hormones production. The purpose of this review is to present the current knowledge on the link between blood levels of sex-hormones in women during the various stages of the female reproductive life (i.e. puberty, menstrual cycle, pregnancy, contraception, and menopause) and the course of schizophrenia. We also attempt to optimize the clinical approach to women with schizophrenia at these different stages.

Specificity proteins 1 and 4 in peripheral blood mononuclear cells in postmenopausal women with schizophrenia: a 24-week double-blind, randomized, parallel, placebo-controlled trial

Accumulating evidence suggests that Specificity Protein 1 (SP1) and 4 (SP4) transcription factors are involved in the pathophysiology of schizophrenia. The therapeutic use of selective oestrogen modulators such as raloxifene added to antipsychotic drugs in the treatment of postmenopausal women with schizophrenia has been investigated in a few clinical trials, which reported an improvement in negative, positive, and general psychopathological symptoms. We aimed to investigate the possible association between peripheral SP protein levels and symptom improvement in postmenopausal women with schizophrenia treated with adjuvant raloxifene. In a subgroup of 14 postmenopausal women with schizophrenia from a 24-week, randomized, parallel, double-blind, placebo-controlled clinical trial (NCT015736370), we investigated changes in SP1 and SP4 protein levels in peripheral blood mononuclear cells. Participants were randomized to either 60 mg/day adjunctive raloxifene or placebo. Psychopathological symptoms were assessed at baseline and at week 24 with the Positive and Negative Syndrome Scale (PANSS). The expression of SP proteins was evaluated by immunoblot, and changes in PANSS scores and protein levels were compared at baseline and after 24 weeks of treatment. An improvement in symptoms was observed in the intervention group, but not in placebo group. Post-treatment protein levels of SP4, but not SP1, correlated with improvements in general and total PANSS subscales in the raloxifene intervention group. A reduction in SP4 levels was found after raloxifene treatment. These results suggest that SP4 may be involved in raloxifene symptom improvement in postmenopausal women and could be a potential candidate for future studies investigating blood-based biomarkers for raloxifene effectiveness.

Raloxifene as a treatment for cognition in women with schizophrenia: the influence of menopause status

Cognitive impairments cause significant functional issues for people with schizophrenia, often emerging before the onset of hallucinations, delusions and other psychosis symptoms. Current pharmacological treatments do not target cognitive dysfunction. Several lines of evidence support the beneficial effects of estrogens on cognition. Raloxifene hydrochloride, a selective estrogen receptor modulator, has been associated with cognitive improvements in healthy postmenopausal women and in schizophrenia, although findings are inconsistent. Using pooled data from two clinical trials, the aim of the current study was to compare the efficacy of 120 mg/day adjunctive raloxifene to placebo for 12 weeks on cognitive performance in women with schizophrenia who were stratified by menopause status (pre-menopausal; peri-menopausal or post-menopausal). A total of sixty-nine participants with a diagnosis of schizophrenia or schizoaffective disorder were included. Cognition was assessed at baseline and study end using the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). Results indicated that after stratifying for menopause status (strata) and adjusting for endogenous hormone levels (estrogen, progesterone, follicle stimulating hormone and luteinising hormone), semantic fluency, picture naming and list recognition change from baseline scores for the raloxifene group differed significantly from the placebo group. The findings from the current study highlight the importance of considering menopause status when interpreting the effects of hormonal treatments.

Sex and gender differences in schizophrenic psychoses-a critical review

Many sex and gender differences in schizophrenic psychoses have been reported, but few have been soundly replicated. A stable finding is the later age of onset in women compared to men. Gender differences in symptomatology, comorbidity, and neurocognition seem to reflect findings in the general population. There is increasing evidence for estrogens being psychoprotective in women and for hypothalamic-pituitary-gonadal dysfunction in both sexes.More methodologically sound, longitudinal, multi-domain, interdisciplinary research investigating both sex (biological) and gender (psychosocial) factors is required to better understand the different pathogenesis and etiologies of schizophrenic psychoses in women and men, thereby leading to better tailored treatments and improved outcomes.

Use of psychotropic medication in women with psychotic disorders at menopause and beyond

PURPOSE OF REVIEW

Drugs have been extensively prescribed for the treatment of psychotic symptoms in schizophrenia and related disorders, as well as for the management of psychotic features in delirium, dementia and affective disorders. The aim of this narrative review is to focus on the recent literature on drug treatment in women with psychosis at the transition to menopause and subsequently.

RECENT FINDINGS

The recent literature emphasizes the following points: the efficacy of antipsychotic medication in psychosis is largely confined to the alleviation of delusions and hallucinations; menopause and ageing alter the kinetics and dynamics of drug action; drugs other than antipsychotics are currently being tested to address the cognitive, affective and negative symptoms of psychotic illnesses; menopausal symptoms add to comorbidities and require simultaneous treatment, raising the probability of deleterious drug interactions; antipsychotic drugs have many side effects and contribute to high mortality rates in the older psychosis population.

SUMMARY

A major implication for research is that antipsychotic drugs with a wider range of action and with fewer side effects are urgently needed. The clinical implications of the pharmacotherapy of psychotic illness are: older women's needs must be assessed through a comprehensive history and review of systems and physical and mental examination. To avoid adverse effects, drug dosages are best kept low and polypharmacy avoided wherever possible. It is important to frequently reassess older patients, as their pharmacotherapy requirements change with age and with comorbidity.

Pharmacotherapy for schizophrenia in postmenopausal women

INTRODUCTION

Reduced estrogen levels at menopause mean a loss of the neuroprotection that is conferred, from puberty until menopause, on women with schizophrenia. The postmenopausal stage of schizophrenia requires therapeutic attention because women with this diagnosis almost invariably experience increased symptoms and increased side effects at this time. So far, few targeted therapies have been successfully developed.

AREAS COVERED

This non-systematic, narrative review is based on the relevant published literature indexed in PubMed. A digital search was combined with a manual check of references from studies in the field of gender differences, menopause and schizophrenia. Aside from the inclusion of a few early classic papers, the review focuses on 21st century basic, psychopharmacologic, and clinical literature on the treatment of women with schizophrenia after menopause.

EXPERT OPINION

Beyond a relatively low dose threshold, all antipsychotic medications have adverse effects, which become more prominent for women at the time of menopause. Estrogen modulators may not help all symptoms of schizophrenia but are, nevertheless, relatively safe and, when used as adjuncts, help to keep antipsychotic doses low, thus reducing the side effect burden. The field is currently moving towards precision medicine and individual genetic profiles will help to determine the efficacy of available treatments in the future.

Treating schizophrenia during menopause

OBJECTIVE

The aim of this review is to examine three questions: What are the risks and benefits of treating women with schizophrenia with hormone therapy (HT) at menopause? Should the antipsychotic regimen be changed at menopause? Do early- and late-onset women with schizophrenia respond differently to HT at menopause?

METHODS

MEDLINE databases for the years 1990 to 2016 were searched using the following interactive terms: schizophrenia, gender, menopause, estrogen, and hormones. The selected articles (62 out of 800 abstracts) were chosen on the basis of their applicability to the objectives of this targeted narrative review.

RESULTS

HT during the perimenopause in women with schizophrenia ameliorates psychotic and cognitive symptoms, and may also help affective symptoms. Vasomotor, genitourinary, and sleep symptoms are also reduced. Depending on the woman's age and personal risk factors and antipsychotic side effects, the risk of breast cancer and cardiovascular disease may be increased. Antipsychotic types and doses may need to be adjusted at menopause, as may be the mode of administration.

CONCLUSIONS

Both HT and changes in antipsychotic management should be considered for women with schizophrenia at menopause. The question about differences in response between early- and late-onset women cannot yet be answered.

Understanding the role of steroids in typical and atypical brain development: Advantages of using a "brain in a dish" approach

Steroids have an important role in growth, development, sexual differentiation and reproduction. All four classes of steroids, androgens, oestrogens, progestogens and glucocorticoids, have varying effects on the brain. Androgens and oestrogens are involved in the sexual differentiation of the brain, and also influence cognition. Progestogens such as progesterone and its metabolites have been shown to be involved in neuroprotection, although their protective effects are timing-dependent. Glucocorticoids are linked with stress and memory performance, also in a dose- and time-dependent manner. Importantly, dysfunction in steroid function has been implicated in the pathogenesis of disease. Moreover, regulating steroid-signalling has been suggested as potential therapeutic avenue for the treatment of a number of neurodevelopmental, psychiatric and neurodegenerative disorders. Therefore, clarifying the role of steroids in typical and atypical brain function is essential for understanding typical brain functions, as well as determining their potential use for pharmacological intervention in the atypical brain. However, the majority of studies have thus far have been conducted using animal models, with limited work using native human tissue or cells. Here, we review the effect of steroids in the typical and atypical brain, focusing on the cellular, molecular functions of these molecules determined from animal models, and the therapeutic potential as highlighted by human studies. We further discuss the promise of human-induced pluripotent stem cells, including advantages of using three-dimensional neuronal cultures (organoids) in high-throughput screens, in accelerating our understanding of the role of steroids in the typical brain, and also with respect to their therapeutic value in the understanding and treatment of the atypical brain.

Women and schizophrenia: planning for the future

The aim of this narrative review is to provide readers with a summary of the recent literature on women and schizophrenia and to address commonly asked questions about the role of gender in this illness. Important gender distinctions were found in the knowledge base around schizophrenia, particularly in the areas of symptom onset, hormonal and immune effects, and antipsychotic drug kinetics and their consequences. We also discuss and address commonly asked questions about gender and schizophrenia. This review concludes that gender differences influence the effectiveness of various treatments and need to be taken into account when planning comprehensive care services for individuals with schizophrenia.

Interactions between estradiol and haloperidol on perseveration and reversal learning in amphetamine-sensitized female rats

There are sex differences associated with schizophrenia, as women exhibit later onset of the disorder, less severe symptomatology, and better response to antipsychotic medications. Estrogens are thought to play a role in these sex differences; estrogens facilitate the effects of antipsychotic medications to reduce the positive symptoms of schizophrenia, but it remains unclear whether estrogens protect against the cognitive symptoms of this disorder. Amphetamine sensitization is used to model some symptoms of schizophrenia in rats, including cognitive deficits like excessive perseveration and slower reversal learning. In this experiment female rats were administered a sensitizing regimen of amphetamine to mimic these cognitive symptoms. They were ovariectomized and administered either low or high estradiol replacement as well as chronic administration of the antipsychotic haloperidol, and were assessed in tests of perseveration and reversal learning. Results of these experiments demonstrated that, in amphetamine-sensitized rats, estradiol alone does not affect perseveration or reversal learning. However, low estradiol facilitates a 0.25mg/day dose of haloperidol to reduce perseveration and improve reversal learning. Combined high estradiol and 0.25mg/day haloperidol has no effect on perseveration or reversal learning, but high estradiol facilitates the effects of 0.13mg/day haloperidol to reduce perseveration and improve reversal learning. Thus, in amphetamine-sensitized female rats, 0.25mg/day haloperidol only improved perseveration and reversal learning when estradiol was low, while 0.13mg/day haloperidol only improved these cognitive processes when estradiol was high. These findings suggest that estradiol facilitates the effects of haloperidol to improve perseveration and reversal learning in a dose-dependent manner.