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

The excitatory-inhibitory balance as a target for the development of novel drugs to treat schizophrenia

The intricate balance between excitation and inhibition (E/I) in the brain plays a crucial role in normative information processing. Dysfunctions in the E/I balance have been implicated in various psychiatric disorders, including schizophrenia (SCZ). In particular, abnormalities in GABAergic signaling, specifically in parvalbumin (PV)-containing interneurons, have been consistently observed in SCZ pathophysiology. PV interneuron function is vital for maintaining an ideal E/I balance, and alterations in PV interneuron-mediated inhibition contribute to circuit deficits observed in SCZ, including hippocampus hyperactivity and midbrain dopamine system overdrive. While current antipsychotic medications primarily target D2 dopamine receptors and are effective primarily in treating positive symptoms, novel therapeutic strategies aiming to restore the E/I balance could potentially mitigate not only positive symptoms but also negative symptoms and cognitive deficits. This could involve, for instance, increasing the inhibitory drive onto excitatory neurons or decreasing the putative enhanced pyramidal neuron activity due to functional loss of PV interneurons. Compounds targeting the glycine site at glutamate NMDA receptors and muscarinic acetylcholine receptors on PV interneurons that can increase PV interneuron drive, as well as drugs that increase the postsynaptic action of GABA, such as positive allosteric modulators of α5-GABA-A receptors, and decrease glutamatergic output, such as mGluR2/3 agonists, represent promising approaches. Preventive strategies aiming at E/I balance also represent a path to reduce the risk of transitioning to SCZ in high-risk individuals. Therefore, compounds with novel mechanisms targeting E/I balance provide optimism for more effective and tailored interventions in the management of SCZ.

Maternal immune activation and estrogen receptor modulation induce sex-specific dopamine-related behavioural and molecular alterations in adult rat offspring

Dopamine dysregulation contributes to psychosis and cognitive deficits in schizophrenia that can be modelled in rodents by inducing maternal immune activation (MIA). The selective estrogen receptor (ER) modulator, raloxifene, can improve psychosis and cognition in men and women with schizophrenia. However, few studies have examined how raloxifene may exert its therapeutic effects in mammalian brain in both sexes during young adulthood (age relevant to most prevalent age at diagnosis). Here, we tested the extent to which raloxifene alters dopamine-related behaviours and brain transcripts in young adult rats, both control and MIA-exposed females and males. We found that raloxifene increased amphetamine (AMPH)-induced locomotor activity in female controls, and in contrast, raloxifene reduced AMPH-induced locomotor activity in male MIA offspring. We did not detect overt prepulse inhibition (PPI) deficits in female or male MIA offspring, yet raloxifene enhanced PPI in male MIA offspring. Whereas, raloxifene ameliorated increased startle responsivity in female MIA offspring. In the substantia nigra (SN), we found reduced Drd2s mRNA in raloxifene-treated female offspring with or without MIA, and increased Comt mRNA in placebo-treated male MIA offspring relative to placebo-treated controls. These data demonstrate an underlying dopamine dysregulation in MIA animals that can become more apparent with raloxifene treatment, and may involve selective alterations in dopamine receptor levels and dopamine breakdown processes in the SN. Our findings support sex-specific, differential behavioural responses to ER modulation in MIA compared to control offspring, with beneficial effects of raloxifene treatment on dopamine-related behaviours relevant to schizophrenia found in male MIA offspring only.

Insights and implications of sexual dimorphism in osteoporosis

Osteoporosis, a metabolic bone disease characterized by low bone mineral density and deterioration of bone microarchitecture, has led to a high risk of fatal osteoporotic fractures worldwide. Accumulating evidence has revealed that sexual dimorphism is a notable feature of osteoporosis, with sex-specific differences in epidemiology and pathogenesis. Specifically, females are more susceptible than males to osteoporosis, while males are more prone to disability or death from the disease. To date, sex chromosome abnormalities and steroid hormones have been proven to contribute greatly to sexual dimorphism in osteoporosis by regulating the functions of bone cells. Understanding the sex-specific differences in osteoporosis and its related complications is essential for improving treatment strategies tailored to women and men. This literature review focuses on the mechanisms underlying sexual dimorphism in osteoporosis, mainly in a population of aging patients, chronic glucocorticoid administration, and diabetes. Moreover, we highlight the implications of sexual dimorphism for developing therapeutics and preventive strategies and screening approaches tailored to women and men. Additionally, the challenges in translating bench research to bedside treatments and future directions to overcome these obstacles will be discussed.

Estrogen and psychosis - a review and future directions

The link between sex hormones and schizophrenia has been suspected for over a century; however, scientific evidence supporting the pharmacotherapeutic effects of exogenous estrogen has only started to emerge during the past three decades. Accumulating evidence from epidemiological and basic research suggests that estrogen has a protective effect in women vulnerable to schizophrenia. Such evidence has led multiple researchers to investigate the role of estrogen in schizophrenia and its use in treatment. This narrative review provides an overview of the effects of estrogen as well as summarizes the recent work regarding estrogen as a treatment for schizophrenia, particularly the use of new-generation selective estrogen receptor modulators.

The Direct and Long-Term Effects of Raloxifene as Adjunctive Treatment for Schizophrenia-Spectrum Disorders: A Double-Blind, Randomized Clinical Trial

BACKGROUND AND HYPOTHESIS

Several studies suggest that raloxifene, a selective estrogen receptor modulator, improves symptoms and cognition in post-menopausal women with Schizophrenia-Spectrum Disorders (SSD). We aimed to assess the effects of adjunctive raloxifene in women and men with SSD.

STUDY DESIGN

This parallel, randomized, double-blind, placebo-controlled trial included adult SSD patients across the Netherlands and Belgium. Participants were stratified by age, sex, and global functioning and randomly assigned 1:1 to 12-week add-on raloxifene or placebo. Primary outcomes were symptom severity at 6, 12, and 38 weeks and cognition at 12 and 38 weeks, as measured with the Positive and Negative Syndrome Scale and the Brief Assessment of Cognition in Schizophrenia, respectively. Intention-to-treat analyses were performed using linear mixed-effect models.

STUDY RESULTS

We assessed 261 patients for eligibility, of which 102 (28% female) were assigned to raloxifene (n = 52) or placebo (n = 48). Although we found no main effect of raloxifene, secondary sex-specific analysis showed that in women, raloxifene had beneficial effects on negative symptoms at week 6 (LSM -2.92; adjusted P = 0.020) and week 12 (LSM -3.12; adjusted P = 0.030), and on working memory at week 38 (LSM 0.73; adjusted P = 0.040), while having negative effects on working memory at week 38 in men (LSM -0.53; adjusted P = 0.026). The number of adverse events was similar between groups.

CONCLUSIONS

Our results do not support the use of raloxifene in patients with SSD in general, but suggest female-specific beneficial effects of raloxifene on negative symptoms and working memory. Our findings encourage further research on sex-specific pharmacotherapeutic treatment.

Evidence-Based Recommendations for the Pharmacological Treatment of Women with Schizophrenia Spectrum Disorders

PURPOSE OF REVIEW

Despite clear evidence that sex differences largely impact the efficacy and tolerability of antipsychotic medication, current treatment guidelines for schizophrenia spectrum disorders (SSD) do not differentiate between men and women. This review summarizes the available evidence on strategies that may improve pharmacotherapy for women and provides evidence-based recommendations to optimize treatment for women with schizophrenia.

RECENT FINDINGS

We systematically searched PubMed and Embase for peer-reviewed studies on three topics: (1) sex differences in dose-adjusted antipsychotic serum concentrations, (2) hormonal augmentation therapy with estrogen and estrogen-like compounds to improve symptom severity, and (3) strategies to reduce antipsychotic-induced hyperprolactinemia. Based on three database studies and one RCT, we found higher dose-adjusted concentrations in women compared to men for most antipsychotics. For quetiapine, higher concentrations were specifically found in older women. Based on two recent meta-analyses, both estrogen and raloxifene improved overall symptomatology. Most consistent findings were found for raloxifene augmentation in postmenopausal women. No studies evaluated the effects of estrogenic contraceptives on symptoms. Based on two meta-analyses and one RCT, adjunctive aripiprazole was the best-studied and safest strategy for lowering antipsychotic-induced hyperprolactinemia. Evidence-based recommendations for female-specific pharmacotherapy for SSD consist of (1) female-specific dosing for antipsychotics (guided by therapeutic drug monitoring), (2) hormonal replacement with raloxifene in postmenopausal women, and (3) aripiprazole addition as best evidenced option in case of antipsychotic-induced hyperprolactinemia. Combining these strategies could reduce side effects and improve outcome of women with SSD, which should be confirmed in future longitudinal RCTs.

Adjunctive agents to antipsychotics in schizophrenia: a systematic umbrella review and recommendations for amino acids, hormonal therapies and anti-inflammatory drugs

QUESTION

This umbrella review and guidelines aimed to provide evidence to support the rational choice of selected adjunctive therapies for schizophrenia.

STUDY SELECTION AND ANALYSIS

Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and World Federation of Societies of Biological Psychiatry (WFSBP)-grading recommendations, 63 randomised control trials (RCTs) (of which 4219 unique participants have completed the RCTs) and 29 meta-analyses were analysed.

FINDINGS

Provisional recommendations (WFSBP-grade 1) could be made for two molecules in augmentation to antipsychotics: (1) N-acetyl-cysteine (NAC, 1200-3600 mg/day, for >12 consecutive weeks) in improving negative symptoms, general psychopathology (positive and negative syndrome scale for schizophrenia (PANSS) general psychopathology factor (G)-G subscale), with the RCTs with the longer duration showing the most robust findings; (2) polyunsaturated fatty acids (3000 mg/day of eicosapentaenoic acid, for >12 weeks) in improving general psychopathology. Weaker recommendations (ie, WFSBP-grade 2) could be drawn for sarcosine (2 g/day) and minocycline (200-300 mg/day) for improving negative symptoms in chronic schizophrenia (not early schizophrenia), and NAC for improving positive symptoms and cognition. Weak recommendations are not ready for clinical practice. There is provisional evidence that oestrogens and raloxifene are effective in some patients, but further research is needed to determine their benefit/risk ratio.

CONCLUSIONS

The results of this umbrella review should be interpreted with caution as the number of RCTs included in the meta-analyses was generally small and the effect sizes were weak or medium. For NAC, two RCTs with low risk of bias have provided conflicting results and the WFSBP-grade recommendation included also the results of meta-analyses. These drugs could be provisionally prescribed for patients for whom no other treatments have been effective, but they should be discontinued if they prove ineffective.

Women with Schizophrenia-Spectrum Disorders After Menopause: A Vulnerable Group for Relapse

BACKGROUND AND HYPOTHESIS

Throughout the life stages of women with schizophrenia-spectrum disorders (SSD), lower estrogen levels are associated with more severe disease course. At perimenopause in the mid-forties, estrogen levels decline to remain persistently low after menopause. This period is hypothesized to increase relapse risk and reduce antipsychotic effectiveness in preventing relapse.

STUDY DESIGN

The cohort of persons with schizophrenia/schizoaffective disorder was identified from Finnish nationwide registers (N = 61 889) and stratified by sex and age <45 vs. ≥45 years. Hospitalizations for psychosis were defined per 5-year age group during the follow-up 1996-2017. Risk of psychosis hospitalization (Adjusted Hazard Ratio, aHR) was assessed using within-individual design, by comparing antipsychotic monotherapy use to nonuse periods in the same individuals for seven dose categories in defined daily doses (DDDs/day).

RESULTS

Starting at age 45-50, women were consistently more often hospitalized for psychosis than their male peers. Women ≥45 had significantly higher aHRs than women <45 at antipsychotic monotherapy >0.6 DDDs/day, and than men at >1.1 DDDs/day. This female-specific age-dependent decrease in effectiveness was present for clozapine doses >0.6 DDDs/day, olanzapine doses >1.4 DDDs/day, and for specific doses of quetiapine (0.9-1.1 DDDs/day) and risperidone (0.6-0.9 DDDs/day).

CONCLUSIONS

While younger women have a lower risk of relapse and generally need a lower antipsychotic dose to prevent rehospitalization than men, antipsychotic effectiveness declines in women after the age of 45. Starting in mid-forties, older women with SSD should be regarded as a vulnerable group that deserve special attention.

The Effect of Menopause on Antipsychotic Response

Background: It has been hypothesized that, whenever estrogen levels decline, psychosis symptoms in women increase. At menopause, this can happen in two main ways: (a) the loss of estrogen (mainly estradiol) can directly affect central neurotransmission, leading to increase in schizophrenia-related symptoms, and (b) the loss of estrogen can decrease the synthesis of enzymes that metabolize antipsychotic drugs, thus weakening their efficacy. Aims and Methods: The aim of this narrative review was to investigate the second possibility by searching PubMed and ClinicalTrials.gov for studies over the last two decades that investigated the metabolism of antipsychotics and their efficacy before and after menopause in women or that studied systemic and local estrogen level effects on the pharmacokinetics and pharmacodynamics of individual antipsychotic drugs. Results: The evidence suggests that symptom level in women with schizophrenia rises after menopause for many reasons beyond hormones but, importantly, there is an estrogen-dependent loss of efficacy related to antipsychotic treatment. Conclusion: Effective clinical intervention is challenging; nevertheless, several promising routes forward are suggested.

Risk for midlife psychosis in women: critical gaps and opportunities in exploring perimenopause and ovarian hormones as mechanisms of risk

Women show a heightened risk for psychosis in midlife that is not observed in men. The menopausal transition (i.e. perimenopause) and accompanying changes in ovarian hormones are theorized to account for this midlife increase in risk. This narrative review aims to empirically examine these theories by reviewing studies of midlife and perimenopausal psychosis risk in women and potential ovarian hormone mechanisms of effects. Clinical and pre-clinical studies examining the effects of midlife age, menopausal stage, and ovarian hormones across adulthood on psychosis risk were identified. Synthesis of this body of work revealed that the peak ages of midlife psychosis risk in women overlap with the age range of key menopausal stages (especially the perimenopausal transition), although studies directly assessing menopausal stage are lacking. Studies examining ovarian hormone effects have almost exclusively focused on earlier developmental stages and events (e.g. pregnancy, the menstrual cycle) and show increases in psychotic symptoms in women and female rats during periods of lower estradiol levels. Estrogen treatment also tends to enhance the effects of neuroleptics in females across species at various reproductive phases. Initial data are promising in suggesting a role for menopausal stage and ovarian hormones in psychosis risk. However, critical gaps in our knowledge base remain, as there is a tendency to rely on indirect and proxy measures of menopausal status and hormones. Opportunities for future research are discussed with the goal of increasing research in this critical area of women's health.

Hormone Targets for the Treatment of Sleep Disorders in Postmenopausal Women with Schizophrenia: A Narrative Review

While the early identification of insomnia in patients with schizophrenia is of clinical relevance, the use of specific compounds to treat insomnia has been studied less in postmenopausal women with schizophrenia. We aimed to explore the effects of melatonin, sex hormones, and raloxifene for the treatment of insomnia in these populations. Although melatonin treatment improved the quality and efficiency of the sleep of patients with schizophrenia, few studies have explored its use in postmenopausal women with schizophrenia. The estrogen and progesterone pathways are dysregulated in major psychiatric disorders, such as in schizophrenia. While, in the context of menopause, a high testosterone-to-estradiol ratio is associated with higher frequencies of depressive symptoms, the effects of estradiol and other sex hormones on sleep disorders in postmenopausal women with schizophrenia has not been sufficiently investigated. Raloxifene, a selective estrogen receptor modulator, has shown positive effects on sleep disorders in postmenopausal women. Future studies should investigate the effectiveness of hormonal compounds on insomnia in postmenopausal women with schizophrenia.

Peri- and Post-Menopausal Women with Schizophrenia and Related Disorders Are a Population with Specific Needs: A Narrative Review of Current Theories

Background: While gender differences in antipsychotic response have been recognized, the potential role of menopause in changing drug efficacy and clinical outcome in schizophrenia related disorders has been understudied. We aimed to review the relevant literature to test whether optimizing menopausal and post-menopausal treatment and addressing specific health needs of this stage in life will improve outcome. Methods: Non-systematic narrative review using the PubMed database (1900–July 2021) focusing on randomized controlled trial results addressing our question. Forty-nine studies met our criteria. Results: Premenopausal women show significantly better antipsychotic response than postmenopausal women. Hormone replacement therapies (HRT) should be used in postmenopausal women with schizophrenia with caution. Raloxifene, combined with antipsychotics, is effective for psychotic and cognitive symptoms in postmenopausal women with schizophrenia and related disorders. Medical comorbidities increase after menopause, but the influence of comorbidities on clinical outcomes has been poorly investigated. Preventive strategies include weighing risks and benefits of treatment, preventing medical comorbidities, and enhancing psychosocial support. Ideal treatment settings for this population warrant investigation. Conclusions: Antipsychotic dose adjustment at menopause is recommended for schizophrenia. Raloxifene may play an important role in permitting dose reduction and lessening adverse effects. Prevention of comorbidities will help to reduce the mortality rate.

Bazedoxifene - a promising brain active SERM that crosses the blood brain barrier and enhances spatial memory

Over 20 years of accumulated evidence has shown that the major female sex hormone 17β-estradiol can enhance cognitive functioning. However, the utility of estradiol as a therapeutic cognitive enhancer is hindered by its unwanted peripheral effects (carcinogenic). Selective estrogen receptor modulators (SERMs) avoid the unwanted effects of estradiol by acting as estrogen receptor antagonists in some tissues such as breast and uterus, but as agonists in others such as bone, and are currently used for the treatment of osteoporosis. However, understanding of their actions in the brain are limited. The third generation SERM bazedoxifene has recently been FDA approved for clinical use with an improved biosafety profile. However, whether bazedoxifene can enter the brain and enhance cognition is unknown. Using mice, the current study aimed to explore if bazedoxifene can 1) cross the blood-brain barrier, 2) rescue ovariectomy-induced hippocampal-dependent spatial memory deficit, and 3) activate neural estrogen response element (ERE)-dependent gene transcription. Using liquid chromatography-mass spectrometry (LC-MS), we firstly demonstrate that a peripheral injection of bazedoxifene can enter the brain. Secondly, we show that an acute intraperitoneal injection of bazedoxifene can rescue ovariectomy-induced spatial memory deficits. And finally, using the ERE-luciferase reporter mouse, we show in vivo that bazedoxifene can activate the ERE in the brain. The evidence shown here suggest bazedoxifene could be a viable cognitive enhancer with promising clinical applicability.

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.

The association between hormones and antipsychotic use: a focus on postpartum and menopausal women

During the postpartum and menopausal periods of women's lives, there is a well-established and significant drop of circulating estrogens. This may be the reason why both these periods are associated with an increased risk for onset or exacerbation of psychiatric disorders. Whether symptoms are mainly affective or mainly psychotic, these disorders are frequently treated with antipsychotic medications, which calls for an examination of the relationship between hormone replacement and antipsychotic agents at these time periods. The aim of this narrative review is to summarize what is known about the association of hormones and antipsychotics in the postnatal period and at menopause. In the review, we focus on estrogen and oxytocin hormones and include, for the most part, only papers published within the last 10 years. Both estradiol and oxytocin have at various times been implicated in the etiology of postpartum disorders, and estrogens, sometimes combined with progesterone, have been tested as potential treatments for these conditions. The role of estradiol as an adjunct to antipsychotics in the prevention of postpartum relapses is currently controversial. With respect to oxytocin, studies are lacking. Psychosis in menopausal and postmenopausal women has been successfully treated with estrogens and selective estrogen-receptor modulators, mainly raloxifene, in addition to antipsychotics. Some symptoms appear to respond better than others. No oxytocin study has specifically targeted postmenopausal women. Because of feedback mechanisms, there is a theoretical danger of therapy with exogenous hormones interfering with endogenous secretion and disturbing the balance among inter-related hormones. When used with antipsychotics, hormones may also affect the metabolism and, hence, the brain level of specific antipsychotics. This makes treatment with antipsychotics plus hormones complicated. Dose, timing and route of intervention may all prove critical to efficacy. While much remains unknown, this literature review indicates that, within standard dose ranges, the combination of hormones and antipsychotics for postnatal and menopausal women suffering severe mental distress can be beneficial, and is safe.

Estrogens and SERMS as adjunctive treatments for schizophrenia

More than thirty years have passed since sex and gender differences were noted in the age of onset, course and outcomes for schizophrenia. The 'estrogen hypothesis" was coined in the 1990's to describe neuroprotective effects of estrogen. Intervention studies in schizophrenia patients with estradiol and selective estrogen receptor modulators (SERMs) are promising but psychiatrists and other health practitioners do not generally take up this useful adjunctive treatment for their female patients with schizophrenia. The reasons for this are manifold, but overall a cultural shift in the practice of psychiatry is needed to recognise the specific needs of women with schizophrenia and tailor treatments, such as hormone adjuncts to improve the outcomes for this significant population. The two main aims of this article are to review the evidence and theory of estrogen treatments in schizophrenia and to recommend translation of adjunctive estrogen treatment into clinical practice for women with schizophrenia.

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.

The effect of raloxifene augmentation in men and women with a schizophrenia spectrum disorder: a systematic review and meta-analysis

Recognizing the robust sex differences in schizophrenia prevalence, the selective estrogen receptor modulator (SERM) raloxifene is a likely candidate for augmentation therapy in this disorder. Therefore, a systematic search was performed using PubMed (Medline), Embase, PsychInfo, and Cochrane Database of Systematic Reviews. Randomized controlled trials investigating the effect of raloxifene in schizophrenia spectrum disorders were included in the quantitative analyses. Outcome measures were psychotic symptom severity, depression, and cognition. Meta-analyses were performed using Comprehensive Meta-Analysis software. A random-effects model was used to compute overall weighted effect sizes in Hedges’ g. Nine studies were included, investigating 561 patients with a schizophrenia spectrum disorder. Raloxifene was superior to placebo in improving total symptom severity (N = 482; Hedge’s g = .57, p = 0.009), as well as positive (N = 561; Hedge’s g = 0.32, p = 0.02), negative (N = 561; Hedge’s g = 0.40, p = 0.02), and general (N = 526; Hedge’s g = 0.46, p = 0.01) subscales, as measured by the Positive and Negative Syndrome Scale. No significant effects were found for comorbid depression and cognitive functioning. Altogether, these results confirm the potential of raloxifene augmentation in the treatment of schizophrenia.