Plasma prolactin levels are associated with the severity of illness in drug-naive first-episode psychosis female patients

Sex differences in prolactin levels and clinical outcomes in patients with a first psychotic episode

AIM

To analyze the clinical, neurocognitive, and functional impact of prolactin levels according to sex in patients with a First Episode Psychosis (FEP).

METHODS

We measured prolactin levels in 221 non-affective FEP patients treated with antipsychotics (AP) and 224 healthy controls, at baseline and 2-year follow-up. We examined whether the relationships between clinical and functional variables were mediated by prolactin, controlling for antipsychotic use, according to sex.

RESULTS

Prolactin levels were higher in patients when compared to controls at both time points. Baseline factors associated with prolactin were chlorpromazine equivalents, attention, and executive functioning. In the FEP group, prolactin levels were associated with functioning and diminished expression in males, and with working memory in females. Prolactin levels (p=0.0134) played a role as a mediator between negative symptomatology (p=0.086) and functional outcome (p=0.008) only in FEP male patients at baseline.

CONCLUSIONS

Prolactin plays a role in the functionality and clinical symptomatology of FEP patients. Our results suggest that pharmacological counselling in patients with hyperprolactinemia at baseline and negative symptomatology might improve their functional and clinical outcomes.

Prolactin: A Mammalian Stress Hormone and Its Role in Cutaneous Pathophysiology

The hormone prolactin (PRL) is best recognised for its indispensable role in mammalian biology, specifically the regulation of lactation. Bearing in mind that the mammary gland is a modified sweat gland, it is perhaps unsurprising to discover that PRL also plays a significant role in cutaneous biology and is implicated in the pathogenesis of a range of skin diseases, often those reportedly triggered and/or exacerbated by psychological stress. Given that PRL has been implicated in over 300 biological processes, spanning reproduction and hair growth and thermo- to immunoregulation, a comprehensive understanding of the relationship between PRL and the skin remains frustratingly elusive. In an historical curiosity, the first hint that PRL could affect skin biology came from the observation of seborrhoea in patients with post-encephalitic Parkinsonism as a result of another global pandemic, encephalitis lethargica, at the beginning of the last century. As PRL is now being postulated as a potential immunomodulator for COVID-19 infection, it is perhaps timeous to re-examine this pluripotent hormone with cytokine-like properties in the cutaneous context, drawing together our understanding of the role of PRL in skin disease to illustrate how targeting PRL-mediated signalling may represent a novel strategy to treat a range of skin diseases and hair disorders.

Antipsychotics-related hyperprolactinaemia among patients with schizophrenia in Maiduguri

Background

Hyperprolactinaemia among patients on antipsychotic medications is generally overlooked due to lack of outwardly visible symptoms, patient resistance to reporting because the symptoms are perceived as shameful, or to clinician's insufficient knowledge.

Aim

The study aimed to evaluate the patterns and correlates of hyperprolactinemia among patients with schizophrenia on antipsychotic medications.

Setting

The study was conducted in a psychiatric facility in Maiduguri, Northeastern Nigeria.

Methods

A total of 209 patients with schizophrenia were evaluated through a cross-sectional design and assayed for serum prolactin with ELISA Kits. Frequencies and percentages were tabulated for categorical variables. Variables with significant associations with hyperprolactinaemia on chi-square (p < 0.05) were subjected to logistic regression analysis.

Results

The prevalence of hyperprolactinaemia was 45.9% in all patients on antipsychotic medication. The prevalence because of the use of typical and atypical antipsychotics was 51.5% and 25.0%, respectively. Hyperprolactinaemia was significantly associated with typical antipsychotics (β = 0314, p = 0.002), high overall drug dosage (β = 2.340, p = 0.003), high-dose typical antipsychotics (β = 3.228, p = 0.000), twice daily dosing frequency (β = 2.751, p = 0.001) and polypharmacy (β = 1.828, p = 0.0024).

Conclusion

The findings support that patients on typical, high-dose antipsychotic medications and polypharmacy have a high prevalence of hyperprolactinaemia. As hyperprolactinaemia is often undetectable, screening and patient psycho-education on the significance of the signs and symptoms of hyperprolactinaemia is required for necessary clinical intervention.

Contribution

The study provides evidence for the rational use of antipsychotic medications in sub-Saharan Africa.

Blood concentrations of anterior pituitary hormones in drug-naïve people with first-episode psychosis: A systematic review and meta-analysis

INTRODUCTION

The role of anterior pituitary hormones - i.e., adrenocorticotropic hormone (ACTH), luteinizing and follicle stimulating hormones (LH and FSH), growth hormone (GH), prolactin (PRL), and thyroid-stimulating hormone (TSH) - in early schizophrenia and psychoses unclear. We thus performed a systematic review and meta-analysis on the blood concentrations of ACTH, LH and FSH, GH, PRL, and TSH in drug-naïve people with first-episode psychosis (FEP) as compared with healthy controls.

METHODS

We searched Embase, MEDLINE, and PsycInfo for articles indexed until September 2022. Data quality was appraised. Random-effects meta-analyses were carried out, generating pooled standardized mean differences (SMDs). Between-study heterogeneity was estimated using the I2 statistic. Sensitivity and meta-regression analyses were performed.

RESULTS

Twenty-six studies were included. Drug-naïve people with FEP, compared to healthy subjects, had higher blood concentrations of ACTH (k = 7; N = 548; SMD = 0.62; 95%CI: 0.29 to 0.94; p < 0.001; I2 = 60.9%) and PRL (k = 17; N = 1757; SMD = 0.85; 95%CI: 0.56 to 1.14; p < 0.001; I2 = 85.5%) as well as lower levels of TSH (k = 6; N = 677; SMD = -0.34; 95%CI: -0.54 to -0.14; p = 0.001; I2 = 29.1%). Meta-regressions did not show any moderating effect of age (p = 0.78), sex (p = 0.21), or symptom severity (p = 0.87) on PRL concentrations in drug-naïve FEP. Available data were not sufficient to perform meta-analyses on FSH, LH, and GH.

CONCLUSIONS

Drug-naïve people with FEP have altered ACTH, PRL, and TSH blood concentrations, supporting the hypothesis that an abnormal anterior pituitary hormone secretion may be involved in the onset of schizophrenia and psychoses. Further research is needed to elucidate the role of pituitary hormones in FEP.

Association of Prolactin, Oxytocin, and Homocysteine With the Clinical and Cognitive Features of a First Episode of Psychosis Over a 1-Year Follow-Up

BACKGROUND

The clinical debut of schizophrenia is frequently a first episode of psychosis (FEP). As such, there is considerable interest in identifying associations between biological markers and clinical or cognitive characteristics that help predict the progression and outcome of FEP patients. Previous studies showed that high prolactin, low oxytocin, and high homocysteine are factors associated with FEP 6 months after diagnosis, at which point plasma levels were correlated with some clinical and cognitive characteristics.

METHODS

We reexamined 75 patients at 12 months after diagnosis to measure the evolution of these molecules and assess their association with clinical features.

RESULTS

At follow-up, FEP patients had lower prolactin levels than at baseline, and patients treated with risperidone or paliperidone had higher prolactin levels than patients who received other antipsychotic agents. By contrast, no changes in oxytocin and homocysteine plasma levels were observed between the baseline and follow-up. In terms of clinical features, we found that plasma prolactin and homocysteine levels were correlated with the severity of the psychotic symptoms in male FEP patients, suggesting that they might be factors associated with psychotic symptomatology but only in men. Together with oxytocin, these molecules may also be related to sustained attention, verbal ability, and working memory cognitive domains in FEP patients.

CONCLUSION

This study suggests that focusing on prolactin, oxytocin, and homocysteine at a FEP may help select adequate pharmacological treatments and develop new tools to improve the outcome of these patients, where sex should also be borne in mind.

Monitoring the Effectiveness of Treatment in Women with Schizophrenia: New Specialized Cooperative Approaches

Women with schizophrenia have specific health needs that differ from those of men and that change through successive life stages. We aimed to review the biopsychosocial literature on schizophrenia that addresses clinically important questions related to the treatment of women, including somatic morbi-mortality, hyperprolactinemia, comorbid substance use disorders, social risk factors, and medication effectiveness/safety. Data search terms were as follows: (Morbidity AND mortality) OR hyperprolactinemia OR ("substance use disorders" OR addictions) OR ("social risk factors") OR ("drug safety" OR prescription) AND women AND schizophrenia. A secondary aim was to describe a method of monitoring and interdisciplinary staff strategies. Schizophrenia patients show an increased risk of premature death from cardiovascular/respiratory disease and cancer compared to the general population. The literature suggests that close liaisons with primary care and the introduction of physical exercise groups reduce comorbidity. Various strategies for lowering prolactin levels diminish the negative long-term effects of hyperprolactinemia. Abstinence programs reduce the risk of victimization and trauma in women. Stigma associated with women who have serious psychiatric illness is often linked to reproductive functions. The safety and effectiveness of antipsychotic drug choice and dose differ between men and women and change over a woman's life cycle. Monitoring needs to be multidisciplinary, knowledgeable, and regular.

De Novo Psychiatric Disorders in a Woman With Giant Prolactinoma Treated With Cabergoline

Dopamine agonists are the first-line treatment of prolactinomas. The risk of developing de novo psychiatric symptoms during dopamine agonist therapy is low. Herein, we report the case of a 42-year-old woman with a giant prolactinoma who developed a psychiatric disorder after 1 day of cabergoline therapy initiation. She presented with amenorrhea, galactorrhea, headaches, and disturbed vision. Biological investigations revealed hyperprolactinemia (2975 ng/ml) with gonadotropin deficiency. Pituitary MRI showed a giant pituitary adenoma. The patient was treated with cabergoline at the dose of 1 mg twice weekly. One day after the treatment initiation, she developed acute delirium with temporospatial disorientation and compulsive medication use. These symptoms disappeared 1 week after the reduction of the dose of cabergoline. Patients with hyperprolactinemia receiving an initial high dose of cabergoline may develop changes in mood and behavior regardless of prior psychiatric history.

Prolactin and morning cortisol concentrations in antipsychotic naïve first episode psychosis: A systematic review and meta-analysis

IMPORTANCE

Alterations in prolactin and cortisol levels have been reported in antipsychotic naïve patients with first episode psychosis (FEP). However, it has been studied in very small samples, and inter-group variability has never been studied before.

OBJECTIVE

To provide estimates of standardized mean differences (SMD) and inter-group variability for prolactin, cortisol awakening response (CAR) and morning cortisol concentrations in antipsychotic naïve FEP (AN-FEP) patients and healthy controls (HC).

DATA SOURCES

BIOSIS, KCI, MEDLINE, Russian Science Citation Index, SciELO, Cochrane, PsycINFO, Web of Science were searched from inception to February 28, 2022.

STUDY SELECTION

Peer-reviewed cohort studies that reported on prolactin or cortisol blood concentrations in AN- FEP patients and HC were included.

DATA EXTRACTION AND SYNTHESIS

Study characteristics, means and standard deviations (SD) were extracted from each article. Inter group differences in magnitude of effect were estimated using Hedges g. Inter-group variability was estimated with the coefficient of variation ratio (CVR). In both cases estimates were pooled using random-effects meta-analysis. Differences by study-level characteristics were estimated using meta-regression. PRISMA guideline was followed (No. CRD42022303555).

MAIN OUTCOMES AND MEASURES

Prolactin, CAR and morning cortisol blood concentrations in AN-FEP group in relation to HC group.

RESULTS

Fourteen studies for prolactin (N = 761 for AN-FEP group, N = 687 for HC group) and twelve studies for morning cortisol (N = 434 for AN-FEP group, N = 528 for HC group) were included. No studies were found in CAR in AN-FEP patients. Mean SMD for prolactin blood concentration was 0.88 (95% CI 0.57, 1.20) for male and 0.56 (95% CI 0.26, 0.87) for female. As a group, AN-FEP presented greater inter-group variability for prolactin levels than HC (CVR=1.28, 95% CI 1.02, 1.62). SMD for morning cortisol concentrations was non-significant: 0.34 (95% CI -0.01, 0.69) and no inter-group variability significant differences were detected: CVR= 1.05 (95% CI 0.91, 1.20). Meta-regression analyses for age and quality were non-significant. Funnel plots did not suggest a publication bias.

CONCLUSIONS AND RELEVANCE

Increased prolactin levels were found in AN-FEP patients. A greater inter-group variability in the AN-FEP group suggests the existence of patient subgroups with different prolactin levels. No significant abnormalities were found in morning cortisol levels. Further research is needed to clarify whether prolactin concentrations could be used as an illness biomarker.

The Involvement of Prolactin in Stress-Related Disorders

The most important and widely studied role of prolactin (PRL) is its modulation of stress responses during pregnancy and lactation. PRL acts as a neuropeptide to support physiological reproductive responses. The effects of PRL on the nervous system contribute to a wide range of changes in the female brain during pregnancy and the inhibition of the hypothalamic-pituitary axis. All these changes contribute to the behavioral and physiological adaptations of a young mother to enable reproductive success. PRL-driven brain adaptations are also crucial for regulating maternal emotionality and well-being. Hyperprolactinemia (elevated PRL levels) is a natural and beneficial phenomenon during pregnancy and lactation. However, in other situations, it is often associated with serious endocrine disorders, such as ovulation suppression, which results in a lack of offspring. This introductory example shows how complex this hormone is. In this review, we focus on the different roles of PRL in the body and emphasize the results obtained from animal models of neuropsychiatric disorders.

Prospective analysis of serum prolactin levels, clinical symptomatology and sexual functions in patients with schizophrenia switched to paliperidone palmitate 3-monthly from paliperidone palmitate 1-monthly: Preliminary findings of the first 3 months

OBJECTIVE

Long-acting injectable (LAI) antipsychotics were developed to improve adherence to schizophrenia treatment. Paliperidone palmitate (PP) has two LAI forms: Monthly (PP1M) and three-monthly (PP3M). PP3M shows less difference in Peak-to-Trough drug concentration levels. This could be related to a lower incidence of hyperprolactinemia, which may negatively affect adherence. We aimed to compare prolactin levels and investigate relationships between prolactin levels, symptomatology and sexual function in patients with schizophrenia after switching from PP1M to PP3M.

METHODS

Twenty-five patients were enrolled. The sociodemographic data form, the Positive and Negative Syndromes Scale (PANSS) and the Arizona Sexual Experience Scale (ASEX) were used. Morning blood samples were drawn to determine prolactin levels.

RESULTS

Prolactin level (p < 0.001), the total score and arousal sub-score of ASEX (respectively; p = 0.015, p = 0.020) and the total score and positive scale of PANSS (respectively; p = 0.017, p = 0.021) were decreased on the 90th day (±15 days).

CONCLUSIONS

After switching to PP3M, the decreases in prolactin levels and potentially related sexual side effects was statistically significant. There may be a difference between two formulations of the same drug in terms of side effects, and there is a need for prospective follow-up studies with larger samples.

The Influence of Oxytocin and Prolactin During a First Episode of Psychosis: The Implication of Sex Differences, Clinical Features, and Cognitive Performance

BACKGROUND

Approximately 3% of the population suffers a first episode of psychosis (FEP), and a high percentage of these patients subsequently relapse. Because the clinical course following a FEP is hard to predict, it is of interest to identify cognitive and biological markers that will help improve the diagnosis, treatment, and outcome of such events and to define new therapeutic targets. Here we analyzed the plasma oxytocin and prolactin levels during an FEP, assessing their correlation with clinical and cognitive features.

METHODS

The oxytocin and prolactin in plasma was measured in 120 FEP patients and 106 healthy controls, all of whom were subjected to a clinical and neuropsychological assessment. Most patients were under antipsychotics. Statistical analyses aimed to identify factors associated with the FEP and to search for associations between the variables. This study is preliminary and exploratory because the P-values were not corrected for multiple comparisons.

RESULTS

FEP patients had less oxytocin, more prolactin, and a poor premorbid IQ, and they performed worse in sustained attention. Male patients with higher prolactin levels experienced more severe psychotic symptoms and required higher doses of antipsychotics. Low oxytocin was associated with poor sustained attention in women, whereas low oxytocin and high prolactin in men correlated with better performance in sustained attention.

CONCLUSION

Low oxytocin, high prolactin, and poor premorbid IQ and sustained attention are factors associated with an FEP, representing potential therapeutic targets in these patients. These biological factors and cognitive domains might play an important role during a FEP, which could help us to develop new strategies that improve the outcomes of this disorder and that should perhaps be gender specific.

A population-based follow-up study shows high psychosis risk in women with PCOS

Polycystic ovary syndrome (PCOS) is a common endocrine disorder affecting up to 18% of women. Besides metabolic and fertility aspects, attention has lately been directed towards the detrimental effect of PCOS on psychological health. The objective of the study was to investigate whether women with PCOS are at higher risk for psychotic disorders. The study population derives from the Northern Finland Birth Cohort 1966 (N = 5889 women). The women with PCOS were identified by two simple questions on oligo-amenorrhea and hirsutism at age 31. Women reporting both symptoms were considered PCOS (N = 124) and asymptomatic women as controls (N = 2145). The diagnosis of psychosis was traced using multiple national registers up to the year 2016. Symptoms of psychopathology were identified using validated questionnaires at age 31. Women with PCOS showed an increased risk for any psychosis by age 50 (HR [95% CI] 2.99, [1.52-5.82]). Also, the risk for psychosis after age 31 was increased (HR 2.68 [1.21-5.92]). The results did not change after adjusting for parental history of psychosis, nor were they explained by body mass index or hyperandrogenism at adulthood. The scales of psychopathology differed between women with PCOS and non-PCOS controls showing more psychopathologies among the affected women. PCOS cases were found to be at a three-fold risk for psychosis, and they had increased psychopathological symptoms. PCOS should be taken into consideration when treating women in psychiatric care. More studies are required to further assess the relationship between PCOS and psychotic diseases.

Prolactin, metabolic and immune parameters in naïve subjects with a first episode of psychosis

BACKGROUND

Prolactin (Prl) is a pleiotropic hormone initially described for its regulation of lactation in mammals but later associated with metabolic and immune homeostasis, stress, inflammatory response and human behavior. Its regulation through dopamine receptors highlights its importance in psychiatry mostly because hyperprolactinemia is a common secondary side effect of dopamine antagonists. Despite its undeciphered patho-physiological mechanisms, hyperprolactinemia in naïve psychosis patients has been widely described. Its consequences might underlie the increased morbidity and early mortality found in naïve subjects as described in the general population where prolactin values have been correlated with inflammatory, immune and metabolic parameters.

METHODS

We aimed to evaluate the correlation between prolactin values and other biochemical parameters (C-reactive Protein-CrP, blood cell count, lipid and hepatic profile, fasting glucose) in a cohort of first episode psychosis naïve subjects (N = 491) stratified by sex. Regression analyses with confounders were performed to evaluate the association.

FINDINGS

Prl displayed significant correlations with C-Reactive Protein (CrP), Low-Density Lipoprotein (LDL), Aspartate Transaminase (AST) for females and High-Density Lipoprotein (HDL) and eosinophil count for males. However, and despite previous specific sex correlations, significant associations were described for CrP, HDL, LDL, AST and ALT without sex interaction and despite confounders such as age, Body Mass Index or smoking status.

CONCLUSIONS

Our results show a specific relation of Prl with immune and metabolic parameters describing a heterogeneous pattern. Our results suggest that prolactin might underlie the excess of morbidity and early mortality in naïve patients through a specific pathway.

Estrogens in schizophrenia: progress, current challenges and opportunities

PURPOSE OF REVIEW

Schizophrenia is a heterogeneous psychiatric disorder with a different, but not necessarily milder clinical presentation in women as compared to men. These sex differences have largely been attributed to the protective role of estrogens. This article reviews the current state of estrogen research in schizophrenia.

RECENT FINDINGS

Estrogens regulate important pathophysiological pathways in schizophrenia, including dopamine activity, mitochondrial function, and the stress system. Estrogen deficiency is common in both sexes and is associated with increases in psychotic symptoms. Hyperprolactinemia causes secondary estrogen deficiency and can be a reaction to stress, or secondary to prolactin-raising antipsychotics. Therefore, prolactin-sparing antipsychotics should be preferred especially in premenopausal women, who are more prone to hyperprolactinemia. Premenopausal women furthermore require lower doses of antipsychotics than men, since estrogens raise the availability and efficacy of antipsychotics.

SUMMARY

The past years have established the importance of estrogens in the pathophysiology of schizophrenia and have shown its relevance to clinical practice through its influence on antipsychotic drug efficacy. Future research should focus on the neurobiological and clinical effect of contraceptives in premenopausal women with schizophrenia. Furthermore, the potential of estrogen-like augmentation with raloxifene and phytoestrogens in schizophrenia should be established in the coming years.

Plasma prolactin is higher in major depressive disorder and females, and associated with anxiety, hostility, somatization, psychotic symptoms and heart rate

Background

Major Depressive Disorder (MDD) is linked to poor physical health including an increased risk of developing cardiometabolic disease (CMD), yet the underlying physiology of this relationship is not clear. One pathophysiological mechanism that may underlie this relationship is neuroendocrine dysregulation, including that of the hormone prolactin. Prolactin has a role in the regulation of stress, and it is linked to anxiety, hostility, and weight gain, which are all implicated in MDD and increased CMD risk. However, little research has examined plasma prolactin in association with psychological symptoms of MDD or biometric indices of CMD risk. Method: Plasma samples of 120 participants (n ​= ​60 meeting DSM-5 criteria for MDD and n ​= ​60 control; age and sex matched) were analysed to assess prolactin concentration. Biometric data (BMI, waist circumference, blood pressure and heart rate) were collected, and participants completed the Brief Symptom Inventory (BSI) and Depression Anxiety Stress Scale (DASS).

Results

Plasma prolactin was higher in participants with MDD versus controls (8.79 ​± ​5.16 ​ng/mL and 7.03 ​± ​4.78 ​ng/mL, respectively; F ​= ​4.528, p ​= ​0.035) and among females versus males (9.14 ​± ​5.57 ​ng/mL and 6.31 ​± ​3.70 ​ng/mL, respectively; F ​= ​9.157, p ​= ​0.003). Prolactin was correlated with several psychological symptoms including anxiety, hostility and somatization, and with heart rate, but not with any other biometric measures.

Conclusions

The results of this study indicate that neuroendocrine dysregulation in MDD may extend to the hormone prolactin, with prolactin being specifically associated with a subset of related psychometric and cardiovascular measures.

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Plasma prolactin is higher in major depressive disorder group than in controls.

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Plasma prolactin is significantly higher in females versus males.

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Prolactin is significantly correlated with heart rate.

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Prolactin is correlated with paranoid ideation, anxiety, hostility, somatization.

Gender-specific approach in psychiatric diseases: Because sex matters

In both animals and human beings, males and females differ in their genetic background and hormonally driven behaviour and show sex-related differences in brain activity and response to internal and external stimuli. Gender-specific medicine has been a neglected dimension of medicine for long time, and only in the last three decades it is receiving the due scientific and clinical attention. Research has recently begun to identify factors that could provide a neurobiological basis for gender-based differences in health and disease and to point to gonadal hormones as important determinants of male-female differences. Animal studies have been of great help in understanding factors contributing to sex-dependent differences and sex hormones action. Here we review and discuss evidence provided by clinical and animal studies in the last two decades showing gender (in humans) and sex (in animals) differences in selected psychiatric disorders, namely eating disorders (anorexia nervosa, bulimia nervosa, binge eating disorder), schizophrenia, mood disorders (anxiety, depression, obsessive-compulsive disorder) and neurodevelopmental disorders (autism spectrum disorders, attention-deficit/hyperactivity disorder).

Phenomenology, Epidemiology and Aetiology of Postpartum Psychosis: A Review

Postpartum psychoses are a severe form of postnatal mood disorders, affecting 1–2 in every 1000 deliveries. These episodes typically present as acute mania or depression with psychosis within the first few weeks of childbirth, which, as life-threatening psychiatric emergencies, can have a significant adverse impact on the mother, baby and wider family. The nosological status of postpartum psychosis remains contentious; however, evidence indicates most episodes to be manifestations of bipolar disorder and a vulnerability to a puerperal trigger. While childbirth appears to be a potent trigger of severe mood disorders, the precise mechanisms by which postpartum psychosis occurs are poorly understood. This review examines the current evidence with respect to potential aetiology and childbirth-related triggers of postpartum psychosis. Findings to date have implicated neurobiological factors, such as hormones, immunological dysregulation, circadian rhythm disruption and genetics, to be important in the pathogenesis of this disorder. Prediction models, informed by prospective cohort studies of high-risk women, are required to identify those at greatest risk of postpartum psychosis.

Pharmacological treatment strategies for lowering prolactin in people with a psychotic disorder and hyperprolactinaemia: A systematic review and meta-analysis

Different therapeutic strategies are used for lowering prolactin concentrations in patients with psychotic disorders with antipsychotic-induced hyperprolactinaemia. We aimed to examine the evidence from open-label studies and randomized clinical trials (RCTs) that studied four prolactin-lowering therapeutic strategies in people with psychotic disorders and hyperprolactinaemia: 1) switching to prolactin-sparing antipsychotics; 2) adding aripiprazole; 3) adding dopamine agonists; and 4) adding metformin. RCTs were included in a meta-analysis. Effect sizes (Hedges' g) of prolactin reductions with each strategy were calculated. Withdrawal rates were also considered. We identified 26 studies. Nine studies explored switching antipsychotic treatment to aripiprazole (n = 4), olanzapine (n = 1), quetiapine (n = 2), paliperidone palmitate (n = 1) or blonanserin (n = 1). Twelve studies tested the addition of aripiprazole. Six studies explored the addition of cabergoline (n = 3), bromocriptine (n = 2) or terguride (n = 1). We also found one meta-analysis testing the addition of metformin to antipsychotic treatment but no other individual studies. A meta-analysis could only be performed for the addition of aripiprazole, the strategy with the best level of evidence. Five RCTs testing the addition of aripiprazole yielded a significant reduction in prolactin concentration compared to placebo (N = 3) or maintaining antipsychotic treatment (N = 2): Hedges' g was -1.35 (CI 95%: -1.93 to -0.76, p < 0.001). The three placebo-controlled RCTs for aripiprazole addition showed similar withdrawal rates for aripiprazole (10.1%) and placebo (11.5%), without significant differences in the meta-analysis. Our study suggests that, in terms of levels of evidence, adding aripiprazole is the first option to be considered for lowering prolactin concentrations in patients with schizophrenia and hyperprolactinaemia.

Neuroendocrinology and neurobiology of sebaceous glands

The nervous system communicates with peripheral tissues through nerve fibres and the systemic release of hypothalamic and pituitary neurohormones. Communication between the nervous system and the largest human organ, skin, has traditionally received little attention. In particular, the neuro-regulation of sebaceous glands (SGs), a major skin appendage, is rarely considered. Yet, it is clear that the SG is under stringent pituitary control, and forms a fascinating, clinically relevant peripheral target organ in which to study the neuroendocrine and neural regulation of epithelia. Sebum, the major secretory product of the SG, is composed of a complex mixture of lipids resulting from the holocrine secretion of specialised epithelial cells (sebocytes). It is indicative of a role of the neuroendocrine system in SG function that excess circulating levels of growth hormone, thyroxine or prolactin result in increased sebum production (seborrhoea). Conversely, growth hormone deficiency, hypothyroidism, and adrenal insufficiency result in reduced sebum production and dry skin. Furthermore, the androgen sensitivity of SGs appears to be under neuroendocrine control, as hypophysectomy (removal of the pituitary) renders SGs largely insensitive to stimulation by testosterone, which is crucial for maintaining SG homeostasis. However, several neurohormones, such as adrenocorticotropic hormone and α-melanocyte-stimulating hormone, can stimulate sebum production independently of either the testes or the adrenal glands, further underscoring the importance of neuroendocrine control in SG biology. Moreover, sebocytes synthesise several neurohormones and express their receptors, suggestive of the presence of neuro-autocrine mechanisms of sebocyte modulation. Aside from the neuroendocrine system, it is conceivable that secretion of neuropeptides and neurotransmitters from cutaneous nerve endings may also act on sebocytes or their progenitors, given that the skin is richly innervated. However, to date, the neural controls of SG development and function remain poorly investigated and incompletely understood. Botulinum toxin-mediated or facial paresis-associated reduction of human sebum secretion suggests that cutaneous nerve-derived substances modulate lipid and inflammatory cytokine synthesis by sebocytes, possibly implicating the nervous system in acne pathogenesis. Additionally, evidence suggests that cutaneous denervation in mice alters the expression of key regulators of SG homeostasis. In this review, we examine the current evidence regarding neuroendocrine and neurobiological regulation of human SG function in physiology and pathology. We further call attention to this line of research as an instructive model for probing and therapeutically manipulating the mechanistic links between the nervous system and mammalian skin.

The role of cortisol and prolactin in the pathogenesis and clinical expression of psychotic disorders

For many years, the study of the psychotic phenotpe and approach to treatment of schizophrenia has been focused on positive psychotic symptoms, although the functional outcome is more clearly associated with negative and cognitive symptoms. Recently, there has been a growing interest in identifying biomarkers associated with these symptoms at early stages of the illness, including the risk of psychosis in vulnerable individuals (at-risk mental states [ARMS]). In this paper, the role of cortisol and prolactin in the clinical expression of psychosis will be reviewed. In examination of the role of these hormones and the risk of developing a psychotic disorder in ARMS individuals, previous studies have suggested potential roles for both cortisol and prolactin. The study of cognitive abilities in recent-onset psychotic patients has suggested that affected cognitive domains differ depending upon the studied hormones: cortisol (processing speed, verbal and working memory) and prolactin (processing speed), with several studies suggesting that there are sex-differences in these associations. All of these results suggest that both cortisol and prolactin contribute to the pathogenesis and clinical expression of psychotic disorders.