Relationship between estrogen and schizophrenia

The relationship between serum prolactin levels and cognitive function in drug-naïve schizophrenia patients: a cross-sectional study

This study aimed to investigate the association between serum prolactin levels and psychiatric symptoms and cognitive function in drug-naïve schizophrenia patients. The study recruited 91 drug-naïve schizophrenia patients and 67 healthy controls. Sociodemographic and clinical data were collected, and cognitive function was assessed using the Measurement and Treatment Research to Improve Cognition in Schizophrenia (MATRICS) Consensus Cognitive Battery (MCCB). Serum prolactin levels were measured, and statistical analyses were performed to examine the relationship between prolactin levels, clinical symptoms, and cognitive function. The study found that drug-naïve schizophrenia patients had severe cognitive deficits compared to healthy controls across all seven domains of the MCCB. However, no correlation was found between these patients' serum prolactin levels and clinical severity or cognitive function. The drug-naïve schizophrenia patients had significant cognitive deficits compared to healthy controls. However, there was no significant relationship between prolactin levels and symptomatology and cognition in drug-naïve schizophrenia patients.

Perimenstrual psychiatric hospitalization: case report and literature review

Despite the fact that menstrual psychosis has been described since the eighteenth century, there are only about 80 cases reported in the literature. The knowledge and awareness about the disorder remain poor, leading to inaccurate diagnoses and suboptimal treatment. This is the case of a 25-year-old woman with recurrent hospitalizations for mental status changes including psychotic phenomena and catatonia that appeared to follow a cyclical pattern that correlated with her menstrual periods, with complete symptom resolution and return to her usual level of functioning between episodes despite continued treatment with antipsychotic medications. This pattern remitted only after hormonal therapy was initiated. Through this case report, the authors review the literature on the menstrual psychoses, exemplified by this case, and discuss treatment options and prognosis. Menstrual psychosis is an underrecognized condition where psychotic symptoms recur cyclically with menses. Given the poor response that this entity shows to antipsychotic treatment, hormonal therapies have a prominent role.

Presynaptic inhibition decreases when estrogen level rises

The objective was to determine estrogen's influence on control of a skeletal muscle through measurements of motorneuron excitability (H:M ratio) and presynaptic inhibition (PI). Estrogen serum concentrations were measured at menses and ovulation of female subjects and compared to male controls. Data were analyzed from 12 women and 13 men reporting no history of knee ligament injury. Women reported regular menstrual cycles and no hormone-based contraceptive use for the previous year. Women were tested at menses (Time1) and ovulation (Time2). Men were tested twice, approximately 14 days apart. Analysis indicated no difference in the H:M ratio between the sexes at either time point. A significant difference for the sexes was detected in the magnitude of estrogen change (∆EST) between observations. At Time1, the male and female estrogen concentrations were not different; however, they were different at Time2, primarily due to the large rise observed in the women. A significant difference between the sexes was also seen in the magnitude of change for PI (∆PI) between observations. As with EST, the levels of PI between the sexes at Time1 were not different; however, a difference existed at Time 2. Estrogen interacts with GABA at several nervous system locations affecting inhibition of synaptic transmission. This is the first study to investigate changes in PI of a skeletal muscle between times of low and high estrogen. Improving the understanding of estrogen's influence on skeletal muscles may provide answers to why noncontact anterior cruciate ligament injuries of the knee occur more frequently in women.

Raloxifene as an adjunctive treatment for postmenopausal women with schizophrenia: a meta-analysis of randomized controlled trials

The aim of this study is to meta-analytically assess the efficacy and safety of adjunctive raloxifene for postmenopausal women with schizophrenia. Six studies with 440 patients, including 225 (51.14%) patients on raloxifene and 215 (48.86%) on placebo who completed 13.71 ± 5.09 weeks of treatment, were included in this study. Meta-analysis of Positive and Negative Syndrome Scale total scores and positive, negative, and general symptom scores [standard mean difference (SMD) -0.22 to -0.55, 95% confidence interval (CI) -1.01 to -0.02, p = 0.04-0.01; I ² = 74-79%] revealed an advantage of adjunctive raloxifene treatment over placebo treatment. There was no significant difference regarding discontinuation rate [risk ratio (RR) = 1.38, p = 0.51] and adverse drug reactions (RR = 1.27, p = 0.57) between the two groups. This meta-analysis showed that adjunctive raloxifene appears to be efficacious and safe for postmenopausal women with schizophrenia. Moreover, raloxifene may be efficacious for patients with less severe symptoms. Future studies with a large sample size are needed to confirm these findings.

Raloxifene adjunctive therapy for postmenopausal women suffering from chronic schizophrenia: a randomized double-blind and placebo controlled trial

Background

Cumulative evidence from epidemiological, preclinical and clinical studies suggests estrogens may have psychoprotective effects in schizophrenic patients. Selective Estrogen Receptor Modulators could have therapeutic benefits in schizophrenia for both sexes without being hazardous to gynecological tissues or having feminizing effects. Few studies have been conducted regarding the effects of raloxifene on postmenopausal women suffering from schizophrenia. We conducted this placebo-controlled trial to compare the add-on effect of raloxifene to risperidone versus risperidone with placebo.

Methods

This was an 8-week, parallel-group, placebo-controlled trial undertaken at two universities affiliated psychiatric Hospitals in Iran. Forty-six postmenopausal women with the definite diagnosis of schizophrenia were enrolled in the study. Patients received risperidone (6 mg/day in 3 divided doses) combined with either placebo (N = 23) or 120 mg/day of raloxifene (N = 23) for 8 weeks. Patients were assessed by a psychiatrist at baseline and at 2 and 8 weeks after the start of medical therapy. Efficacy was defined as the change from baseline to endpoint in score on Positive and Negative Syndrome Scale (PANSS).

Results

For PANSS scores, the main effect comparing two types of intervention was not significant [F (1, 48) = 1.77, p = 0.18]. For positive subscale scores, there was marginal significant interaction between intervention type and time [F (2, 47) = 2.93, p = 0.06] and there was substantial main effect for time [F (2, 47) = 24.39, p = 0.001] within both groups showing reduction in positive subscale scores across the three time periods. In addition, the main effect comparing two types of intervention was significant [F (1, 48) = 3.78, p = 0.02]. On the other hand, for negative subscale scores, the main effect comparing two types of intervention was not significant [F (1, 48) = 1.43, p = 0.23]. For general subscale scores, the main effect comparing two types of intervention was not significant [F (1, 48) = 0.03, p = 0.86].

Conclusions

According to our findings, raloxifene as an adjunctive treatment to risperidone was only superior in improvement of positive symptoms and it was not effective in treating negative and general psychopathology symptoms.

Trial registration

The trial was registered at the Iranian registry of clinical trials: IRCT201205131556N42

Special biological issues in the management of women with schizophrenia

Schizophrenia is a debilitating and pervasive mental illness with devastating effects on psychological, cognitive and social wellbeing, and for which current treatment options are far from ideal. Gender differences and the influence of the female reproductive life cycle on the onset, course and symptoms of schizophrenia and the discovery of estrogen's remarkable psychoprotective properties in animal models led to the proposal of the 'estrogen protection hypothesis' of schizophrenia. This has fueled the recent successful investigation of estradiol as a potential adjuvant therapeutic agent in the management of schizophrenia in women. This review explains the scientific rationale behind the estrogen hypothesis and how it can be clinically utilized to address concerns unique to the care of women with schizophrenia.

Role of estrogen treatment in the management of schizophrenia

Increasing evidence from epidemiological, preclinical and clinical studies suggests that estrogens may exert psychoprotective effects in schizophrenia. Observations of gender differences in the onset and course of schizophrenia have prompted exploration of the effects of estrogen on the CNS. The aim of this paper is to provide an overview of different applications of adjunctive estrogen as a possible treatment for symptoms of schizophrenia in both men and women. Recent trials have suggested that estrogen augmentation therapy may be able to enhance the management of schizophrenia; however, the clinical application of estrogen as a treatment has been limited by potential side effects, the most worrying being breast and uterine cancer in women, and feminization in men. Selective estrogen receptor modulators (SERMs), however, may offer therapeutic benefits for both men and women with schizophrenia without posing threat to breast and uterine tissue and without feminizing effects. The use of estrogen opens up new possibilities for both men and women in the treatment of severe mental illnesses such as schizophrenia. With further preclinical and clinical research, it is hoped that this promising field of hormone modulation can continue to evolve and eventually be translated into real therapeutic potential.

Emotion processing in women with schizophrenia is menstrual cycle phase and affective valence dependent: an FMRI study

Despite a large number of functional neuroimaging investigations of emotion processing in schizophrenia, very few have included women. In the present study 21 schizophrenia and 23 healthy women underwent functional MRI (3T) on two occasions (during the follicular and luteal phase of their menstrual cycle) while viewing blocks of emotionally negative, positive and neutral images. During exposure to negatively charged images patients showed relatively less activations than controls during the luteal phase, but no between-group differences were observed during the follicular phase. In contrast, the exposure to positively valenced material produced no significant interaction, but the main effect of group; schizophrenia patients exhibited less activation than healthy controls during both phases of the menstrual cycle. This is the first study demonstrating that atypical neural activations associated with emotion processing in women diagnosed with schizophrenia depend on the menstrual cycle phase and on the affective valence of presented stimuli.

Abnormally rapid reversal learning and reduced response to antipsychotic drugs following ovariectomy in female rats

Epidemiological and clinical life cycle studies indicate that favorable illness course and better response to antipsychotic drugs (APDs) in women with schizophrenia are positively correlated with estrogen levels. Accordingly, the estrogen hypothesis of schizophrenia proposes a neuroprotective role of estrogen in women vulnerable to schizophrenia. Previously we demonstrated in the rat that low levels of estrogen induced by ovariectomy led to disruption of latent inhibition (LI) reflecting impairment of selective attention, a core deficit of schizophrenia. LI disruption was reversed by 17β-estradiol and the atypical APD clozapine, whereas the typical APD haloperidol was ineffective unless co-administered with 17β-estradiol. Here we aimed to extend these findings by testing ovariectomized rats in another selective attention task, discrimination reversal. Ovariectomy led to a loss of selective attention as manifested in abnormally rapid reversal. The latter was normalized by high dose of 17β-estradiol (150 μg/kg) and clozapine (2.5mg/kg), but not by haloperidol (0.1mg/kg) or lower doses of 17β-estradiol (10 and 50 μg/kg). However, co-administration of haloperidol with 17β-estradiol (50 μg/kg) was effective. In sham rats low 17β-estradiol (10 μg/kg) produced rapid reversal, while high 17β-estradiol (150 μg/kg), haloperidol alone, or haloperidol-17β-estradiol combination reduced reversal speed. Clozapine did not affect reversal speed in sham rats. These results strengthen our previous results in suggesting that schizophrenia-like attentional abnormalities as well as reduced response to APDs in female rats are associated with low level of gonadal hormones. In addition, they support the possibility that estrogen may have an antipsychotic-like action in animal models.

The role of oestrogen and other hormones in the pathophysiology and treatment of schizophrenia

The theory that many serious mental illnesses, in particular psychoses such as schizophrenia, may have a significant hormonal aetiological component is fast gaining popularity and the support of scientific evidence. Oestrogen in particular has been substantially investigated as a potential mediator of brain function in schizophrenia. Epidemiological and life-cycle data point to significant differences in the incidence and course of schizophrenia between men and women suggests a protective role of oestrogen. In vitro and in vivo preclinical research confirms oestradiol's interactions with central neurotransmitter systems implicated in the pathogenesis of schizophrenia, while results from randomised controlled trials investigating the antipsychotic potential of oestrogen have been positive. Research into other neuroactive hormones with possible effects on mental state is a rapidly evolving field that may hold new promise. Given that schizophrenia and related psychoses are pervasive and debilitating conditions for which currently available treatments are often only partially effective and entail a high risk of serious side-effects, novel therapeutic strategies are needed. The literature reviewed in this paper suggests that hormones such as oestrogen could be a viable option, and it is hoped that with further research and larger trials, the oestrogen hypothesis can be translated into effective clinical practice.

Association of increased prenatal estrogen with risk factors for schizophrenia

The author previously described a theoretical cause of schizophrenia based on the effects of estrogenic endocrine disruption. In the current review, the author describes how increased estrogen during pregnancy increases susceptibility to certain viral infections associated with increased risk for schizophrenia. The review further discusses how prenatal estrogen exposure could explain associations of schizophrenia with autoimmune diseases, urban environments, and stress. Based on the association of increased estrogen with schizophrenia risk factors, the author proposes increased prenatal estrogen as a unifying factor, perhaps the primary event, in the etiology of schizophrenia.

Schizophrenia, cancer and obstetric complications in an evolutionary perspective-an empirically based hypothesis

OBJECTIVE

Patients diagnosed with schizophrenia have reduced fecundity and premature mortality (both accidental and violent) with no obvious compensatory advantages among kin. The prevalence of the disorder is around 0.7/1%, higher than the expected prevalence of spontaneous mutations. Genes favoring schizophrenia may have been positively selected in the environment of evolutionary adaptation. Literature on potential adaptive genes is reviewed within an evolutionary framework.

METHODS

Literature search on major scientific search engine (PubMed/Medline, Ovid/PsychInfo) on papers aimed at investigating potential pathways justifying a mutation-selection balanced model. Findings are presented with a narrative touch to favor readability and understanding.

RESULTS

Reduced incidence of cancer in both patients diagnosed with schizophrenia and their siblings was reported worldwide. Such findings are notable given higher cancer risk factors in schizophrenia, i.e., smoking, alcohol abuse, obesity, poor diet, and poor adherence to therapy. Some genes involved in cancer proliferation might as well confer protective advantage in immune-surveillance, inflammation, vascular proliferation or apoptosis that otherwise will adversely affect early neurodevelopment.

CONCLUSION

Evidence that reduced risk of certain somatic diseases is associated with schizophrenia is quite significant to progress in the evolutionary epidemiological analysis of psychopathology.

Rapid estradiol modulation of neuronal connectivity and its implications for disease

Estrogens have multiple actions in the brain including modulating synaptic plasticity, connectivity, and cognitive behaviors. While the classical view of estrogens are as endocrine signals, whose effects manifest via the regulation of gene transcription, mounting evidence has been presented demonstrating that estrogens have rapid effects within specific areas of the brain. The emergence that 17 β-estradiol can be produced locally in the brain which can elicit rapid (within minutes) cellular responses has led to its classification as a neurosteroid. Moreover, recent studies have also begun to detail the molecular and cellular underpinnings of how 17 β-estradiol can rapidly modulate spiny synapses (dendritic spines). Remodeling of dendritic spines is a key step in the rewiring of neuronal circuitry thought to underlie the processing and storage of information in the forebrain. Conversely, abnormal remodeling of dendritic spines is thought to contribute to a number of psychiatric and neurodevelopmental disorders. Here we review recent molecular and cellular work that offers a potential mechanism of how 17 β-estradiol may modulate synapse structure and function of cortical neurons. This mechanism allows cortical neurons to respond to activity-dependent stimuli with greater efficacy. In turn this form of plasticity may provide an insight into how 17 β-estradiol can modulate the rewiring of neuronal circuits, underlying its ability to influencing cortically based behaviors. We will then go on to discuss the potential role of 17 β-estradiol modulation of neural circuits and its potential relevance for the treatment of psychiatric and neurodevelopmental disorders.

Genetic variability in estrogen disposition: Potential clinical implications for neuropsychiatric disorders

Variability in the physiological levels of neuroactive estrogens is widely believed to play a role in predisposition to several disorders of the central nervous system. Local biosynthesis of estrogens in the brain as well as their circulating serum levels are known to contribute to this pool of neuroactive steroids. It has been well accepted that estrogens modulate neuronal functions by affecting genesis, differentiation, excitability, and degeneration of nerve cells. These actions of estrogens appear to be more prominent in females with higher concentrations and marked variability of circulating serum levels occurring over a woman's lifetime. However, our knowledge regarding the variability of neuroactive steroid levels is very limited. Furthermore, several studies have recently reported differences in the synchronization of circulating and neuronal levels of estradiol. In the absence of reliable circulating steroid levels, knowledge of genetic variability in estrogen disposition may play a determining factor in predicting altered susceptibility or severity of neuropsychiatric disorders in women. Over the past decade, several genetic variants have been linked to both differential serum estrogen levels and predisposition to diverse types of neuropsychiatric disorders in women. Polymorphisms in genes encoding estrogen-metabolizing enzymes as well as estrogen receptors may account for this phenotypic variability. In this review, we attempt to show the contribution of genetics in determining estrogenicity in females with a particular emphasis on the central nervous system. This knowledge will further provide a driving force for unearthing the novel field of "Estrogen Pharmacogenomics." © 2010 Wiley-Liss, Inc.

Sex-dependent antipsychotic capacity of 17β-estradiol in the latent inhibition model: a typical antipsychotic drug in both sexes, atypical antipsychotic drug in males

The estrogen hypothesis of schizophrenia suggests that estrogen is a natural neuroprotector in women and that exogenous estrogen may have antipsychotic potential, but results of clinical studies have been inconsistent. We have recently shown using the latent inhibition (LI) model of schizophrenia that 17β-estradiol exerts antipsychotic activity in ovariectomized (OVX) rats. The present study sought to extend the characterization of the antipsychotic action of 17β-estradiol (10, 50 and 150 μg/kg) by testing its capacity to reverse amphetamine- and MK-801-induced LI aberrations in gonadally intact female and male rats. No-drug controls of both sexes showed LI, ie, reduced efficacy of a previously non-reinforced stimulus to gain behavioral control when paired with reinforcement, if conditioned with two but not five tone-shock pairings. In both sexes, amphetamine (1 mg/kg) and MK-801 (50 μg/kg) produced disruption (under weak conditioning) and persistence (under strong conditioning) of LI, modeling positive and negative/cognitive symptoms, respectively. 17β-estradiol at 50 and 150 μg/kg potentiated LI under strong conditioning and reversed amphetamine-induced LI disruption in both males and females, mimicking the action of typical and atypical antipsychotic drugs (APDs) in the LI model. 17β-estradiol also reversed MK-induced persistent LI, an effect mimicking atypical APDs and NMDA receptor enhancers, but this effect was observed in males and OVX females but not in intact females. These findings indicate that in the LI model, 17β-estradiol exerts a clear-cut antipsychotic activity in both sexes and, remarkably, is more efficacious in males and OVX females where it also exerts activity considered predictive of anti-negative/cognitive symptoms.

Contrasting effects of increased and decreased dopamine transmission on latent inhibition in ovariectomized rats and their modulation by 17beta-estradiol: an animal model of menopausal psychosis?

Women with schizophrenia have later onset and better response to antipsychotic drugs (APDs) than men during reproductive years, but the menopausal period is associated with increased symptom severity and reduced treatment response. Estrogen replacement therapy has been suggested as beneficial but clinical data are inconsistent. Latent inhibition (LI), the capacity to ignore irrelevant stimuli, is a measure of selective attention that is disrupted in acute schizophrenia patients and in rats and humans treated with the psychosis-inducing drug amphetamine and can be reversed by typical and atypical APDs. Here we used amphetamine (1 mg/kg)-induced disrupted LI in ovariectomized rats to model low levels of estrogen along with hyperfunction of the dopaminergic system that may be occurring in menopausal psychosis, and tested the efficacy of APDs and estrogen in reversing disrupted LI. 17beta-Estradiol (50, 150 microg/kg), clozapine (atypical APD; 5, 10 mg/kg), and haloperidol (typical APD; 0.1, 0.3 mg/kg) effectively reversed amphetamine-induced LI disruption in sham rats, but were much less effective in ovariectomized rats; 17beta-estradiol and clozapine were effective only at high doses (150 microg/kg and 10 mg/kg, respectively), whereas haloperidol failed at both doses. Haloperidol and clozapine regained efficacy if coadministered with 17beta-estradiol (50 microg/kg, an ineffective dose). Reduced sensitivity to dopamine (DA) blockade coupled with spared/potentiated sensitivity to DA stimulation after ovariectomy may provide a novel model recapitulating the combination of increased vulnerability to psychosis with reduced response to APD treatment in female patients during menopause. In addition, our data show that 17beta-estradiol exerts antipsychotic activity.

A female advantage in basic face recognition is absent in schizophrenia

Healthy females outperform males on face recognition tasks. Relative to healthy individuals, schizophrenia patients are impaired at face perception. Yet, it is unclear whether the female advantage found in healthy controls is preserved in females with schizophrenia. In the present study, we compared male and female patients and healthy controls on two basic face perception tasks - detection and identity discrimination. In the detection task, subjects located an upright or inverted line-drawn face (or tree) embedded within a larger line-drawing. In the identity discrimination task, subjects determined which of two side-by-side face images matched an earlier presented face image. Healthy females were significantly more accurate than healthy males on face detection, but not on identity discrimination. However, female patients were not more accurate than male patients on either task. On both upright face detection and face identity discrimination, healthy controls significantly outperformed patients. Patients' performance on face detection was closely associated with tree detection and IQ scores, as well as level of psychosis. This pattern of results suggests that a female advantage in basic face perception is no longer available in schizophrenia, and that this absence may be related to a generalized deficit factor which acts to level performance across sexes, and putative changes in sex-related neurobiological differences associated with schizophrenia.

Disruption of latent inhibition induced by ovariectomy can be reversed by estradiol and clozapine as well as by co-administration of haloperidol with estradiol but not by haloperidol alone

INTRODUCTION

Epidemiological and clinical life cycle studies have indicated that the more favorable illness course and the better response to antipsychotic drugs (APDs) in women with schizophrenia correlate with high levels of estrogen, whereas increased vulnerability to exacerbation and relapse and reduced sensitivity to treatment are associated with low estrogen levels. Accordingly, the estrogen hypothesis of schizophrenia proposes that estrogen has a neuroprotective effect in women vulnerable to schizophrenia.

MATERIALS AND METHODS

Latent inhibition (LI), the capacity to ignore stimuli that received nonreinforced preexposure prior to conditioning, is disrupted in acute schizophrenia patients and in rats and humans treated with the psychosis inducing drug amphetamine. Disruption of LI is reversible by typical and atypical APDs. The present study tested whether low levels of estrogen induced by ovariectomy (OVX) would lead to disruption of LI in female rats and whether such disruption would be normalized by estrogen replacement treatment and/or APDs.

RESULTS

Results showed that OVX led to LI disruption, which was reversed by 17beta-estradiol (150 microg/kg) and the atypical APD clozapine (5 mg/kg), but not by the typical APD haloperidol (0.1, 0.2, 0.3 mg/kg). Haloperidol regained efficacy when administered with 17beta-estradiol (50 microg/kg).

DISCUSSION

These results provide the first demonstration in rats that low levels of hormones can induce a pro-psychotic state that is resistant to at least typical antipsychotic treatment. This constellation may mimic states seen in schizophrenic women during periods associated with low levels of hormones such as the menopause.

The interrelationships among sex hormone concentrations, motoneuron excitability, and anterior tibial displacement in women and men

CONTEXT

Sex hormone fluctuations have been implicated as a contributing factor to the high rates of noncontact injury to the anterior cruciate ligament in females.

OBJECTIVE

To determine the strength of the relationships among variables of sex hormone concentrations, motoneuron excitability, and anterior tibial displacement (ATD) in women and men and to determine if these relationships differ between the sexes.

DESIGN

Cohort study.

SETTING

Sports medicine laboratory.

PATIENTS OR OTHER PARTICIPANTS

Twenty-eight regularly menstruating women (age = 22.4 +/- 3.4 years) and 15 men (age = 22.3 +/- 3.7 years) participated in the study.

INTERVENTION(S)

Fluctuations in sex hormones were determined for the participants. Female participants were tested every other day of their menstrual cycles, whereas male participants were tested every fourth day during the 28-day period.

MAIN OUTCOME MEASURE(S)

We measured Hoffmann reflexes (maximum Hoffmann reflex [H(max)] to maximum M-wave [M(max)] ratio in the soleus), ATD under a 134-N load, and saliva concentrations of estrogen and progesterone. The independent variable was sex. Pearson product moment correlation coefficients were calculated for each participant by pairing measurements made on the same day. Two-tailed independent-samples t tests were used to determine the difference between the male and female correlations for each variable.

RESULTS

Over the course of the study, the relationships between H(max)ratioM(max) and estrogen, H(max)ratioM(max) and progesterone, ATD and estrogen, and ATD and progesterone were not different between the sexes. However, the relationship between ATD and progesterone was different between the sexes (P = .036).

CONCLUSIONS

The observed correlations did not support our hypothesis that the relationships between sex hormone levels and reflex activity or between sex hormone levels and ATD would be different for women compared with men. If sex hormone concentrations significantly contribute to anterior cruciate ligament ruptures because of changes in laxity or in motoneuron excitability, their mechanism of action is likely multifactorial and complex.

Estrogen and comprehension of metaphoric speech in women suffering from schizophrenia: results of a double-blind, placebo-controlled trial

OBJECTIVE

The effects of estrogen on comprehension of metaphoric speech, word fluency, and verbal ability were investigated in women suffering from schizophrenia. The issue of estrogen-dependent neuropsychological performance could be highly relevant because women with schizophrenia frequently suffer from hypoestrogenism.

METHOD

A placebo-controlled, double-blind, crossover study using 17beta-estradiol for replacement therapy and as an adjunct to a naturalistic maintenance antipsychotic treatment was carried out over a period of 8 months. Nineteen women (mean age = 38.0 years, SD = 9.9 years) with schizophrenia were included in the study. Comprehension of metaphoric speech was measured by a lexical decision paradigm, word fluency, and verbal ability by a paper-and-pencil test.

RESULTS

Significant improvement was seen for the activation of metaphoric meaning during estrogen treatment (P = .013); in contrast, no difference was found for the activation of concrete meaning under this condition. Verbal ability and word fluency did not improve under estrogen replacement therapy either.

CONCLUSIONS

This is the very first study based on estrogen intervention instead of the physiological hormone changes to examine the estrogen effects on neuropsychological performance in women with schizophrenia. In addition, it is the first time that the effect of estrogen on metaphoric speech comprehension was investigated in this context. While in a previous study estrogen therapy as adjunct to a naturalistic maintenance treatment with antipsychotics did not show an effect on psychopathology measured by a rating scale, a significant effect of estrogen on the comprehension of metaphoric speech and/or concretism, a main feature of schizophrenic thought and language disturbance, was found in the present study. Because the improvement of formal thought disorders and language disturbances is crucial for social integration of patients with schizophrenia, the results may have implications for the treatment of these individuals.

Testosterone and gonadotropins but not estrogen associated with spatial ability in women suffering from schizophrenia: a double-blind, placebo-controlled study

The aim of this study was to investigate the association between estrogen and spatial ability tasks in women suffering from schizophrenia. For this purpose, a placebo-controlled, double-blind, three-time cross-over study using 17beta-estradiol combined with norethisterone acetate for replacement therapy and as an adjunct to a naturalistic maintenance antipsychotic treatment was carried out over a period of 8 months. Nineteen women (mean age=38.0 years, SD=9.9 years) with schizophrenia hospitalized for the first time or repeatedly were included in the study. Sex hormones - 17beta-estradiol, luteinizing hormone (LH), follicle-stimulating hormone (FSH), prolactin, testosterone, and dehydroepiandrosterone sulfate - were measured and the patients completed a neuropsychological test in the last two active drug and/or placebo phases. Three different spatial ability tasks - spatial orientation, spatial visualization, and flexibility of closure - were measured by a paper-and-pencil test. No association between estrogen and spatial ability was found; however, in an additional exploratory data analysis, high levels of testosterone, LH, and FSH correlated significantly with performance in the flexibility of closure task. This is the very first study, based on estrogen intervention instead of physiological hormone changes, to examine the association between estrogen and spatial ability in women with schizophrenia.

Molecular mechanisms of schizophrenia

Schizophrenia is a complex disorder, where family, twin and adoption studies have been demonstrating a high heritability of the disease and that this disease is not simply defined by several major genes but rather evolves from addition or potentiation of a specific cluster of genes, which subsequently determines the genetic vulnerability of an individual. Linkage and association studies suggest that a genetic vulnerablility, is not forcefully leading to the disease since triggering factors and environmental influences, i.e. birth complications, drug abuse, urban background or time of birth have been identified. This has lead to the assumption that schizophrenia is not only a genetically defined static disorder but a dynamic process leading to dysregulation of multiple pathways. There are several different hypothesis based on several facets of the disease, some of them due to the relatively well-known mechanisms of therapeutic agents. The most widely considered neurodevelopmental hypothesis of schizophrenia integrates environmental influences and causative genes. The dopamine hypothesis of schizophrenia is based on the fact that all common treatments involve antidopaminergic mechanisms and genes such as DRD2, DRD3, DARPP-32, BDNF or COMT are closely related to dopaminergic system functioning. The glutamatergic hypothesis of schizophrenia lead recently to a first successful mGlu2/3 receptor agonistic drug and is underpinned by significant findings in genes regulating the glutamatergic system (SLC1A6, SLC1A2 GRIN1, GRIN2A, GRIA1, NRG1, ErbB4, DTNBP1, DAAO, G72/30, GRM3). Correspondingly, GABA has been proposed to modulate the pathophysiology of the disease which is represented by the involvement of genes like GABRA1, GABRP, GABRA6 and Reelin. Moreover, several genes implicating immune, signaling and networking deficits have been reported to be involved in the disease, i.e. DISC1, RGS4, PRODH, DGCR6, ZDHHC8, DGCR2, Akt, CREB, IL-1B, IL-1RN, IL-10, IL-1B. However, molecular findings suggest that a complex interplay between receptors, kinases, proteins and hormones is involved in schizophrenia. In a unifying hypothesis, different cascades merge into another that ultimately lead to the development of symptoms adherent to schizophrenic disorders.