Circadian rhythm of vital signs, norepinephrine, epinephrine, thyroid hormones, and cortisol in schizophrenia

Identification of key circadian rhythm genes in skin aging based on bioinformatics and machine learning

Skin aging is often accompanied by disruption of circadian rhythm and abnormal expression of circadian rhythm-related genes. In this study, we downloaded skin aging expression datasets from the GEO database and utilized bioinformatics and machine learning methods to explore circadian rhythm genes and pathways involved in skin aging, revealing the pathological and molecular mechanisms of skin aging. Results showed that 39 circadian rhythm-related genes (CRGs) were identified in skin aging, and these CRGs were enriched in signaling pathways such as glucagon signaling pathway, insulin resistance, thyroid hormone signaling pathway, and adipocytokine signaling pathway. Three key skin aging-related CRGs, SIRT1, ARNTL, and ATF4, were identified based on machine learning. Additionally, we found that skin aging was associated with infiltration of immune cells including NK cells activated, Macrophages M1, Mast cells resting, T cells CD4 memory activated, and Macrophages M2, and the expression of the three key skin aging-related CRGs was correlated with these immune cells. Finally, SIRT1, ARNTL, and ATF4 were all down-regulated in skin aging and had a good ability to distinguish young skin tissue from aging skin tissue. In conclusion, three key CRGs, including SIRT1, ARNTL, and ATF4, which are closely related to skin aging, were obtained based on bioinformatics and machine learning technology screening. These three key CRGs were potential risk genes for skin aging and also associated with changes in the immune microenvironment in skin aging. The language used in this paragraph follows the guidelines for scientific writing specified by SCI, making it clear and concise.

Association between thyroid function and psychotic symptoms in adolescents with major depressive disorder: A large sample sized cross-sectional study in China

Backgrounds

Thyroid function was associated with depression and psychotic symptoms; however, little research has focused on its role in coexisting psychotic symptoms in adolescents with depressive disorder. This study aimed to explore the association between thyroid function and psychotic symptoms among depression adolescents.

Methods

A total of 679 adolescent patients (aged 12-18) diagnosed as depressive disorder were recruited. Their socio-demographic, clinical data and thyroid function parameters were collected. The severity of psychotic symptoms was measured according to the assessment measure in DSM-5. Based on the severity of psychotic symptoms, patients were distributed into psychotic depression (PD) and non-psychotic depression (NPD) subgroups, respectively.

Results

The prevalence rate of PD was 52.7% among adolescents with depressive disorder in this study. PD patients were younger (p < 0.01), with more female (p < 0.001) and non-Han nationality (p < 0.01), and presented serum FT4 level decrease (p < 0.01). PD patients displayed a higher rate of abnormal thyroid relevant parameters (p < 0.05). 35.2% of PD patients presented at least one abnormal parameter among all five parameters tested (TSH, TT3, FT3, TT4, and FT4), compared to 27.4% among NPD patients. Further logistic regression analysis indicated that increased serum FT4 level was a protective effect of PD with an adjusted odds ratio (OR) of 0.615. We did not find a statistically significant difference in the family history of mental disorders, serum TSH, TT3, FT3, and TT4 levels.

Conclusions

Our results suggested a high prevalence of PD among depression adolescents, associated with younger age, female, non-Han nationality, and decreased serum FT4 level. We recommend that adolescents with depressive disorder regularly screen their serum FT4 levels for better clinical outcomes.

Taurine prevents MK-801-induced shoal dispersion and altered cortisol responses in zebrafish

Schizophrenia is a chronic neuropsychiatric disorder characterized by a shortened lifespan and significant impaired social and vocational functioning. Schizophrenic patients can present hypothalamic-pituitary-adrenal (HPA) axis dysfunctions and cortisol dysregulation, which play an important role on the etiology onset, exacerbation, and relapsing of symptoms. Based on its intrinsic neuroprotective properties, taurine is considered a promising substance with beneficial role on various brain disorders, including schizophrenia. Here, we evaluated the effects of taurine on shoaling behavior and whole-body cortisol levels in zebrafish treated with dizocilpine (MK-801), which elicits schizophrenia-like phenotypes in animal models. Briefly, zebrafish shoals (4 fish per shoal) were exposed to dechlorinated water or taurine (42, 150, or 400 mg/L) for 60 min. Then, saline (PBS, pH 7.4 or 2.0 mg/kg MK-801) were intraperitoneally injected and zebrafish behavior was recorded 15 min later. In general, MK-801 disrupted shoaling behavior and reduced whole-body cortisol levels in zebrafish. All taurine pretreatments prevented MK-801-induced increase in shoal area, while 400 mg/L taurine prevented the MK-801-induced alterations in neuroendocrine responses. Moreover, all taurine-pretreated groups showed increased geotaxis, supporting a modulatory role in the overall dispersion pattern of the shoal. Collectively, our novel findings show a potential protective effect of taurine on MK-801-induced shoal dispersion and altered neuroendocrine responses, fostering the use of zebrafish models to assess schizophrenia-like phenotypes.

Interoception abnormalities in schizophrenia: A review of preliminary evidence and an integration with Bayesian accounts of psychosis

Schizophrenia research has traditionally focused almost exclusively on how the brain interprets the outside world. However, our internal bodily milieu is also central to how we interpret the world and construct our reality: signals from within the body are critical for not only basic survival, but also a wide range of brain functions from basic perception, emotion, and motivation, to sense of self. In this article, we propose that interoception-the processing of bodily signals-may have implications for a wide range of clinical symptoms in schizophrenia and may thus provide key insights into illness mechanisms. We start with an overview of interoception pathways. Then we provide a review of direct and indirect findings in various interoceptive systems in schizophrenia and interpret these findings in the context of computational frameworks that model interoception as hierarchical Bayesian inference. Finally, we propose a conceptual model of how altered interoceptive inference may contribute to specific schizophrenia symptoms-negative symptoms in particular-and suggest directions for future research, including potential new avenues of treatment.

Effects of antipsychotics on circadian rhythms in humans: a systematic review and meta-analysis

Antipsychotics are widely used to treat psychiatric illness and insomnia. However, the etiology of insomnia is multifactorial, including disrupted circadian rhythms. Several studies show that antipsychotics might modulate even healthy circadian rhythms. The purpose of this systematic review is to integrate current knowledge about the effects of antipsychotics on the circadian rhythms in humans, and to conduct a meta- analysis with the available data. Nine electronic databases were searched. We followed the PRISMA guidelines and included randomized controlled trials (RCTs), non-RCTs, case-control studies, case series, and case reports. Of 7,217 articles, 70 were included. The available data was mainly from healthy individuals, or patients having schizophrenia, but the findings showed a transdiagnostic impact on circadian parameters. This was consistently seen as decreased amplitude of cortisol, melatonin, and body temperature. Particularly, a meta-analysis of 16 RCTs measuring cortisol rhythm showed that antipsychotics, especially atypical antipsychotics, decreased the cortisol area under the curve and morning cortisol level, compared to placebo. The data with melatonin or actigraphy was limited. Overall, this evidence about the circadian effect of antipsychotics showed a need for longitudinal, real-time monitoring of specific circadian markers to differentiate a change in amplitude from a shift in phasing, and for knowledge about optimal timing of administration of antipsychotics, according to individual baseline circadian parameters. Standardizing selection criteria and outcome methods could facilitate good quality intervention studies and evidence-based treatment guidelines. This is relevant considering the accumulating evidence of the high prevalence and unfavorable impact of disrupted circadian rhythms in psychiatric disorders.

Disrupted circadian rhythms and mental health

During the evolution of life, the temporal rhythm of our rotating planet was internalized in the form of circadian rhythms. Circadian rhythms are ~24h internal manifestations that drive daily patterns of physiology and behavior. These rhythms are entrained (synchronized) to the external environment, primarily by the light-dark cycle, and precisely controlled via molecular clocks located within the suprachiasmatic nucleus of the hypothalamus. Misalignment and/or disruption of circadian rhythms can have detrimental consequences for human health. Indeed, studies suggest strong associations between mental health and circadian rhythms. However, direct interactions between mood regulation and the circadian system are just beginning to be uncovered and appreciated. This chapter examines the relationship between disruption of circadian rhythms and mental health. The primary focus will be outlining the association between circadian disruption, in the form of night shift work, exposure to light at night, jet lag, and social jet lag, and psychiatric illness (i.e., anxiety, major depressive disorder, bipolar disorder, and schizophrenia). Additionally, we review animal models of disrupted circadian rhythms, which provide further evidence in support of a strong association between circadian disruption and affective responses. Finally, we discuss future directions for the field and suggest areas of study that require further investigation.

HPA axis in psychotic major depression and schizophrenia spectrum disorders: Cortisol, clinical symptomatology, and cognition

The Hypothalamic Pituitary Adrenal (HPA) axis has been implicated in the pathophysiology of a variety of mood and cognitive disorders. Neuroendocrine studies have demonstrated HPA axis overactivity in major depression, a relationship of HPA axis activity to cognitive performance, and a potential role of HPA axis genetic variation in cognition. In schizophrenia differential HPA activity has been found, including higher rates of non-suppression to dexamethasone challenge and higher salivary cortisol levels, which have been a premonitory risk factor for conversion to psychosis in adolescents at risk for developing schizophrenia. The present study investigated the simultaneous roles HPA axis activity and clinical symptomatology play in poor cognitive performance. Patients with major depression with psychosis (PMD) or schizophrenia spectrum disorder (SCZ) and healthy controls (HC) were studied. All participants underwent a diagnostic interview and psychiatric ratings, a comprehensive neuropsychological battery, and overnight hourly blood sampling for cortisol. Cognitive performance did not differ between the clinical groups, though they both performed more poorly than the HC's across a variety of cognitive domains. Across all subjects, cognitive performance was negatively correlated with higher cortisol, and PMD patients had higher evening cortisol levels than did SCZ and HCs. Cortisol and clinical symptoms, as well as age, sex, and antipsychotic use predicted cognitive performance. Diathesis stress models and their links to symptomatology, cognition, and HPA function are discussed.

Catecholamines in Post-traumatic Stress Disorder: A Systematic Review and Meta-Analysis

Studies on the association between post-traumatic stress disorder (PTSD) and levels of catecholamines have yielded inconsistent results. The aim of this study was to conduct a systematic review and meta-analysis to assess whether concentrations of the catecholamines dopamine, norepinephrine, and epinephrine are associated with PTSD. This study searched relevant articles in the following databases: PubMed, Embase, Web of Science, and Psyc-ARTICLES. Each database was searched from its inception to September, 2018. Data related to catecholamine concentrations were extracted for patients with PTSD and the controls to calculate standardized mean differences and to evaluate effect sizes. A meta-analysis was then performed to compare the concentration of each catecholamine between the two groups in blood and/or urine samples. Heterogeneity was quantified using I² and its significance was tested using the Q statistics. Subgroup analyses of the types of controls, PTSD assessment tools, and assayed methods used in the studies were performed to explore sources of heterogeneity among studies. Random-effects models were used to combine results from selected studies. A total of 1,388 articles were identified, of which 27 were included in the final analysis. Heterogeneity was high; hence random-effects models were used to combine results of selected studies. Results revealed significantly higher norepinephrine levels in people with PTSD than in the controls [standardized mean difference (SMD) = 0.35, 95% confidence interval (CI): 0.13 to 0.57, p = 0.002]. No difference was found in dopamine and epinephrine concentrations between the two groups. Elevated norepinephrine levels may be an important indicator for PTSD.

Clinical correlates of hypothalamic-pituitary-adrenal axis measures in individuals at risk for psychosis and with first-episode psychosis

Hypothalamic-pituitary-adrenal (HPA) axis alterations in at-risk mental states (ARMS) resemble those observed in established psychosis but are less consistent. We aimed to explore HPA axis abnormalities in both first-episode psychosis (FEP) and ARMS patients, while controlling for psychopathological symptoms. We studied 21 ARMS, 34 FEP patients and 34 healthy subjects. Clinical assessment included psychopathological symptoms (positive, negative, disorganized, excited and depressive symptoms) and stress measures. Saliva cortisol levels were determined at awakening, 30' and 60' post-awakening, 10:00 h, 23:00 h and 10:00 h on the day after the administration of 0.25 mg of dexamethasone, which occurred at 23:00 h. Three HPA axis measures were calculated: cortisol awakening response (CAR), cortisol diurnal slope and cortisol suppression ratio of the dexamethasone suppression test (DST). There were no significant differences between groups in HPA axis measures. However, when exploring the relationship between HPA axis measures and psychopathological symptoms, in ARMS subjects (but not FEP patients), a flatter cortisol slope was associated with more prominent negative symptoms, whereas a blunted CAR was associated with excited symptoms. Although no significant differences in HPA axis measures were found between diagnostic groups, subtle abnormalities in the CAR or circadian cortisol rhythmicity might be important for the phenotype of ARMS individuals.

Altered circadian patterns of salivary cortisol in individuals with schizophrenia: A critical literature review

This article focuses on stress vulnerability in schizophrenia through an integrated clinical and biological approach. The objective of this article is to better understand the relationships between vulnerability, stress and schizophrenia. First, the concept of vulnerability is defined and several models of vulnerability in schizophrenia are reviewed. Second, a section is developed on the biology of stress, and more specifically on the stress responses of the hypothalamo-pitutary adrenal (HPA) axis. Then, studies of cortisol circadian rhythms are summarized, suggesting hyper-reactivity of the HPA axis in patients with schizophrenia and high risk individuals for schizophrenia. The results support the models of stress vulnerability in schizophrenia and the hypothesis of high cortisol levels as an endophenotype in this disorder. In conclusion, this article highlights the interest of studying the cortisol circadian rhythms in schizophrenia and opens the perspective to identify high risk individuals for schizophrenia by measuring circadian patterns of salivary cortisol.

Schizophrenia: the role of sleep and circadian rhythms in regulating dopamine and psychosis

Schizophrenia has long been associated with abnormalities in circadian rhythms and sleep. Up until now, there have been no thorough reviews of the potential mechanisms behind the myriad of circadian and sleep abnormalities observed in schizophrenia and psychosis. We present evidence of sleep playing an important role in psychosis predominantly mediated by dopaminergic pathways. A synthesis of both human and animal experimental work suggests that the interplay between sleep and dopamine is important in the generation and maintenance of psychosis. In particular, both animal and human data point to sleep disruption increasing dopamine release and sensitivity. Furthermore, elevated dopamine levels disrupt sleep and circadian rhythms. The synthesis of knowledge suggests that circadian rhythms, dopamine dysregulation, and psychosis are intricately linked. This suggests that treatment of circadian disturbance may be a useful target in improving the lives and symptoms of patients with schizophrenia.

Ultradian Variation of Nerve Growth Factor Plasma Levels in Healthy and Schizophrenic Subjects

Some studies in animal models showed that several neurotrophins may be implicated in the regulation of light-dependent suprachiasmatic pacemaker and in other functions implicated in long-term memory acquisition during sleep. However, no data are known about the role played by NGF in ultradian regulation in humans. The aim of this study was to investigate whether or not there is a natural diurnal fluctuation during daytime in healthy and schizophrenic subjects with a normal light/dark cycle. In a sample of 33 subjects (10 male schizophrenics and 23 healthy subjects) an ELISA assay was used to study the ultradian NGF cycle in blood samples at 9.00, 13.00 and 20.00 hours. The study showed an ultradian rhythm of NGF in healthy subjects with a “V” trend: higher at 9:00 and 20:00 and lower at 13:00. We also show significant differences between male and female controls. No NGF ultradian rhythm among schizophrenic patients compared to healthy subjects was found. The results of this study lead to a rhythmic NGF regulation that appears altered in schizophrenics, where higher levels in the morning and lower levels in the evening were observed, compared to the controls, and support the hypothesis of a role played by NGF in schizophrenia.

Diurnal cortisol variation and cortisol response to an MRI stressor in schizophrenia and bipolar disorder

Markers of HPA axis function, including diurnal cortisol rhythm and cortisol responses to stress or pharmacological manipulation, are increasingly reported as disrupted in schizophrenia (SZ) and bipolar disorder (BD). However, there has been no direct comparison of cortisol responses to stress in SZ and BD in the same study, and associations between cortisol dysfunction and illness characteristics remain unclear. In this study we used spline embedded linear mixed models to examine cortisol levels of SZ and BD participants at waking, during the first 45min after waking (representing the cortisol awakening response; CAR), during the period of rapid cortisol decline post the awakening response, and in reaction to a stressor (MRI scan), relative to healthy controls (HC). Contrary to expectations, neither SZ nor BD showed differences in waking cortisol levels, CAR, or immediate post-CAR decline compared to HC; however, waking cortisol levels were greater in BD relative to SZ. In response to the MRI stressor, the SZ group showed a significant absence of the expected increase in cortisol responsivity to stress, which was seen in both the BD and HC groups. Clinical factors affecting the CAR differed between SZ and BD. In SZ, higher antipsychotic medication dosage was associated with a steeper incline of the CAR, while greater positive symptom severity was associated with a more blunted CAR, and greater levels of anxiety were associated with the blunted cortisol response to stress. In BD, longer illness duration was associated with a steeper incline in CAR and lower levels of waking cortisol. These results suggest that cortisol responses may normalize with medication (in SZ) and longer illness duration (in BD), in line with findings of aberrant cortisol levels in the early stages of psychotic disorders.

Diurnal neurobiological alterations after exposure to clozapine in first-episode schizophrenia patients

BACKGROUND

Irregular circadian rhythm and some of its most characteristic symptoms are frequently observed in patients with schizophrenia. However, changes in the expression of clock genes or neuropeptides that are related to the regulation of circadian rhythm may influence the susceptibility to recurrence after antipsychotic treatment in schizophrenia, but this possibility has not been investigated.

METHODS

Blood samples were collected from 15 healthy male controls and 13 male schizophrenia patients at 4h intervals for 24h before and after treatment with clozapine for 8 weeks. The outcome measures included the relative expression of clock gene mRNA PERIOD1 (PER1), PERIOD2 (PER2), PERIOD3 (PER3) and the levels of plasma cortisol, orexin, and insulin.

RESULTS

Compared with healthy controls, schizophrenia patients presented disruptions in diurnal rhythms of the expression of PER1, PER3, and NPAS2 and the release of orexin, accompanied by a delayed phase in the expression of PER2, decreases in PER3 and NPAS2 expression, and an increase in cortisol levels at baseline. Several of these disruptions (i.e., in PER1 and PER3 expression) persisted after 8 weeks of clozapine treatment, similar to the decreases in the 24-h expression of PER3 and NPAS2. Clozapine treatment for 8 weeks significantly decreased the 24-h levels of PER2 and increased the 24-h levels of insulin.

CONCLUSION

These persistent neurobiological changes that occur after 8 weeks of clozapine treatment may contribute to the vulnerability to recurrence and efficacy of long-term maintenance treatment in schizophrenia.

Levothyroxine Augmentation in Clozapine Resistant Schizophrenia: A Case Report and Review

There are many reports that show different thyroid abnormalities in schizophrenia without clear establishment of their role in etiology and treatment outcome of schizophrenia. Among these reports, there are only a few that consider a role for thyroid hormones as augmenting agents in the treatment with antipsychotic drugs. This case report outlines symptom subsidence of a patient with clozapine refractory paranoid schizophrenia and normal thyroid function who added levothyroxine to clozapine and found that symptoms of psychosis returned once levothyroxine was discontinued. Although this observation needs to be confirmed in controlled clinical trials, we aimed to discuss possible hypothesized mechanisms underlying this observation.

Revisiting thyroid hormones in schizophrenia

Thyroid hormones are crucial during development and in the adult brain. Of interest, fluctuations in the levels of thyroid hormones at various times during development and throughout life can impact on psychiatric disease manifestation and response to treatment. Here we review research on thyroid function assessment in schizophrenia, relating interrelations between the pituitary-thyroid axis and major neurosignaling systems involved in schizophrenia's pathophysiology. These include the serotonergic, dopaminergic, glutamatergic, and GABAergic networks, as well as myelination and inflammatory processes. The available evidence supports that thyroid hormones deregulation is a common feature in schizophrenia and that the implications of thyroid hormones homeostasis in the fine-tuning of crucial brain networks warrants further research.

Impaired neuroendocrine and immune response to acute stress in medication-naive patients with a first episode of psychosis

Little is known about how the biological stress response systems--the autonomic nervous system (ANS), the hypothalamic-pituitary-adrenal (HPA) axis, and the immune system--function during psychosis. Results of studies on the effect of stress on the immune and autonomic system in patients with schizophrenia are inconsistent. The present study investigates whether the stress response is impaired in medication-naive patients with a first episode of psychosis. Ten male patients with a first episode of psychosis and 15 controls were exposed to the stress of public speaking. Parameters of the ANS (heart rate and catecholamines), the HPA axis (plasma adrenocorticotropic hormone [ACTH] and cortisol), and the immune system (number and activity of natural killer [NK] cells) were measured. Peak responses were calculated to examine the relationship between stress-induced activation of the different systems. Subjective stress and anxiety before and during the task were assessed. Patients and controls displayed similar autonomic responses to acute stress. However, there was an impaired HPA axis response, slow onset and return of ACTH, and flattened cortisol response and a reduced increase in number NK cells and NK cell activity in patients with a first episode of psychosis. Furthermore, in patients, the relationship between the different stress response systems was weaker or absent compared with controls. These findings indicate that impairments in stress processing are associated with the endophenotype of psychosis and are not a result of illness progression or antipsychotic medication.

A randomised controlled study of risperidone and olanzapine for schizophrenic patients with neuroleptic-induced acute dystonia or parkinsonism

The objective of this study was to compare the effects of risperidone and olanzapine in schizophrenic patients with intolerant extrapyramidal side effects (EPS) on first generation antipsychotics. We conducted an 8-week, rater-blinded, flexible dose study. Seventy patients with schizophrenia, who met the DSM-IV research criteria of having neuroleptic-induced acute dystonia or parkinsonism, were randomly assigned to risperidone or olanzapine group. The primary outcome was a comparison of the incidence of concomitant anticholinergic drugs usage between the groups to manage their acute dystonia and parkinsonism. The average doses of risperidone and olanzapine from baseline to study end point were 1.8-3.5 mg/day and 7.7-11.7 mg/day, respectively. There were no significant differences in demographic data, severity of EPS or psychotic symptoms between the groups at baseline assessment. Patients taking risperidone had significantly higher incidence of using anticholinergic drugs to manage acute dystonia or parkinsonism overall during the study (OR = 5.17, 95%CI = 1.49-17.88, P = 0.013). There was no significant between-group difference in the changing of rating scales of EPS and psychotic symptoms. The results of our study favour olanzapine as a better choice in schizophrenic patients with intolerant EPS. Double-blinded, fixed dose and different ethnical study for EPS-intolerant schizophrenic patients is needed to confirm the results of our study.

A systematic review of hypothalamic-pituitary-adrenal axis function in schizophrenia: implications for mortality

There is convincing evidence that environmental stress plays a significant role in modifying both mental and physical health. The biological mechanisms linking stress to ill health are not fully understood, but significant evidence points to a central role of the stress axes; the hypothalamic- pituitary-adrenal (HPA) axis and the sympathetic nervous system. Together these two systems link the brain and the body and are crucial in maintaining homeostasis as well as improving an organism's survival chances in the face of environmental challenge. There is evidence of altered HPA axis function in people with a range of mental disorders, and this may in part explain the poor physical health of people with psychotic, mood and anxiety disorders. This paper systematically reviews HPA axis function in people with schizophrenia and relates this to the pattern of physical health seen in this disease. In summary, the evidence suggests people with schizophrenia can experience both hyper- and hypo-function of the HPA axis. It is likely that this contributes to the pattern of poor physical health and premature mortality suffered by people with schizophrenia, in particular the high rates of cardiovascular and metabolic disturbance.

Diurnal cortisol patterns of young male patients with schizophrenia

AIMS

It has been suggested that schizophrenic patients are more vulnerable to stress than healthy persons, and that stressors can trigger a psychotic episode or worsen symptoms. The biological system often studied in relation to stress is the hypothalamic-pituitary-adrenal (HPA) axis, which controls the release of cortisol. We investigated whether the diurnal basal activity of the HPA axis differed between young male patients with schizophrenia and healthy controls.

METHODS

Twenty-seven male patients (mean age 22 ± 5 years) and 38 healthy male control subjects (mean age 22 ± 3 years) were included in the present study. Saliva was sampled at five time points during the day: directly after awakening, 30 min thereafter, and at 12.00 hours, 16.00 hours and 22.00 hours.

RESULTS

The cortisol concentration decreased significantly more during the day in the patient group thanin the control group. Patients also showed a significantly decreased area under the curve with respect to the increase, again indicating that the cortisol concentrations decreased more during the day in patients than in controls. Both the morning increase and the area under the curve with respect to the increase were significantly negatively correlated with negative symptom severity.

CONCLUSIONS

Patients with schizophrenia showed a different daytime sensitivity of the HPA axis. Our findings further suggest that an increase in negative symptom severity is related to a decreased HPA axis sensitivity.

Sex differences in the cortisol response to awakening in recent onset psychosis

A dysregulation of the hypothalamus-pituitary-adrenal (HPA) axis has been suggested as a factor in the etiology and exacerbation of psychosis, but has not been reported consistently. Sex differences are apparent in many aspects of psychotic disorders and may explain some of the equivocation associated with the regulation of the HPA axis in the illness. The present study compared the cortisol response to awakening (CRA) in 27 patients (16 men and 11 women) with recent onset of psychosis (within the past 2 years) and 40 age and gender matched controls. Within the patient group, we also assessed the relationship between the CRA and positive and negative symptoms of psychosis, anxiety and depression. The CRA in patients was not significantly different from controls. However, within the patient group, we observed a significant sex difference, with a blunted cortisol response to awakening in men but not in women (F=7.26; p<0.002). This difference could not be explained by differences between male and female patients in awakening time, medication, or diagnosis of schizophrenia vs. affective psychosis. Cortisol levels were not related to symptom measures. Our findings demonstrate a dysregulation of the HPA axis in male patients with recent onset of psychosis. This sex specificity might be related to and explain in part the unfavorable course of the illness observed in men.

Monitoring patients to improve physical health and treatment outcome

Patients with schizophrenia suffer a number of comorbidities and a range of potential side effects from their medication, which contribute to a negative impact on their quality of life, and are sometimes responsible for lack of compliance and relapse. Side effects, in particular, can be identified by physicians, but only if they examine their patients regularly. Many physicians would suggest that this is good clinical practice for treating patients with schizophrenia, whatever the intended medication. This continuous monitoring might include weight gain, cognitive effects, and blood tests. In fact, patients appreciate being carefully monitored and it contributes to a good patient/physician relationship. This interaction has benefits in terms of impact on compliance and better control of symptoms due to treatment adherence (to appropriate doses), because it enables action before the patient stops taking medication. Good clinical practice suggests that investment in patient monitoring is offset by improved clinical outcomes.

Olanzapine orally disintegrating tablet vs. risperidone oral solution in the treatment of acutely agitated psychotic patients

OBJECTIVE

Efficacy and tolerability of risperidone oral solution (RIS-OS) and olanzapine orally disintegrating tablet (OLZ-ODT) were compared for the treatment of acute psychotic agitation.

METHOD

During a 2-month period, patients scoring > or =15 on the Excited Component for Positive and Negative Syndrome Scale (PANSS-EC) were assigned to treatment with OLZ-ODT (n=34) or RIS-OS (n=53) on psychiatric emergency situations, and assessed every 15 min.

RESULTS

Two (OLZ-ODT and RIS-OS) by five (0-, 15-, 30-, 45- and 60-min time points) repeated-measures analysis of variance revealed only a significant main effect of time course on PANSS-EC (F=82.2, P<.0001). No differences in the number of patients receiving additional injection due to worsening were found (OLZ-ODT, 11.8%; RIS-OS, 9.4%). No differences in rate of extrapyramidal symptoms and patient satisfaction with assigned treatment were found. However, patients in the OLZ-ODT group recovered significantly more from tachycardia than those in the RIS-OS group (t=2.17, P=.03).

CONCLUSION

OLZ-ODT and RIS-OS treatments yielded similar improvements in acutely agitated patients who accepted oral medication. However, on one physiological parameter (i.e., tachycardia) OLZ-ODT might be superior to RIS-OS. Physiological indicators may also be useful for measuring levels of agitation.

Minireview: The circadian clockwork of the suprachiasmatic nuclei--analysis of a cellular oscillator that drives endocrine rhythms

The secretion of hormones is temporally precise and periodic, oscillating over hours, days, and months. The circadian timekeeper within the suprachiasmatic nuclei (SCN) is central to this coordination, modulating the frequency of pulsatile release, maintaining daily cycles of secretion, and defining the time base for longer-term rhythms. This central clock is driven by cell-autonomous, transcriptional/posttranslational feedback loops incorporating Period (Per) and other clock genes. SCN neurons exist, however, within neural circuits, and an unresolved question is how SCN clock cells interact. By monitoring the SCN molecular clockwork using fluorescence and bioluminescence videomicroscopy of organotypic slices from mPer1::GFP and mPer1::luciferase transgenic mice, we show that interneuronal neuropeptidergic signaling via the vasoactive intestinal peptide (VIP)/PACAP2 (VPAC2) receptor for VIP (an abundant SCN neuropeptide) is necessary to maintain both the amplitude and the synchrony of clock cells in the SCN. Acute induction of mPer1 by light is, however, independent of VIP/VPAC2 signaling, demonstrating dissociation between cellular mechanisms mediating circadian control of the clockwork and those mediating its retinally dependent entrainment to the light/dark cycle. The latter likely involves the Ca(2+)/cAMP response elements of mPer genes, triggered by a MAPK cascade activated by retinal afferents to the SCN. In the absence of VPAC2 signaling, however, this cascade is inappropriately responsive to light during circadian daytime. Hence VPAC2-mediated signaling sustains the SCN cellular clockwork and is necessary both for interneuronal synchronization and appropriate entrainment to the light/dark cycle. In its absence, behavioral and endocrine rhythms are severely compromised.

Stress and HPA-axis functioning in young people at ultra high risk for psychosis

It is thought that hypothalamic-pituitary-adrenal (HPA) axis functioning mediates between the experience of stress and development of psychotic symptoms. This study aimed to evaluate this model in a cohort of young people at ultra high risk (UHR) of psychosis. Information about the experience of psychological symptoms and recent stressful experiences was obtained from 23 young people who met UHR criteria. Plasma samples were taken to assess cortisol and glucocorticoid receptor numbers, and an MRI scan was also performed. Plasma cortisol levels were significantly and positively correlated with the experience of 'hassles' but not with the experience of stressful life events. Significant positive associations were also found between plasma cortisol levels and level of depression and anxiety. No significant relationships were found between plasma cortisol level and global psychopathology, psychotic symptomatology, functioning or pituitary and hippocampal volumes. These results suggest that the number of hassles experienced by young people at UHR of psychosis could be an important factor in raising their cortisol levels, which might, in turn, affect the severity of depressive and anxiety symptoms. No other relationships were found between plasma cortisol levels and the experience of psychotic symptoms, functioning or hippocampal and pituitary volumes. These results indicate possible impairment in HPA-axis functioning in the early stages of psychotic illness, but further investigation of the relationships between these parameters is required.

A new look at the neural diathesis--stress model of schizophrenia: the primacy of social-evaluative and uncontrollable situations

The neural diathesis-stress model of schizophrenia proposes that stress, through its effects on cortisol production, acts upon a preexisting vulnerability to trigger and/or worsen the symptoms of schizophrenia. In line with its focus on the neurobiology of stress response in schizophrenia, this model treats stressors as a homogeneous category. Recent research has shown that, in healthy individuals, cortisol is most strongly produced in response to stressors that result from perceived uncontrollable threats to important goals and/or social-evaluative threats. We hypothesize that it is specifically these stressors that trigger and/or worsen the symptoms of schizophrenia in those with a preexisting vulnerability. This hypothesis may provide a way of making sense of contradictory findings on the relations between stress and schizophrenia. We propose some empirical tests of this hypothesis and explore implications for the treatment and management of the disorder.

Cryptochrome1 maybe a candidate gene of schizophrenia

During the last 10 years, we have witnessed major progress in the genetic study of schizophrenia, but gene-mapping efforts have been hampered by the complex mode of inheritance and the likelihood of multiple genes of small effect. In view of the complexity, it may be instructive to understand the biological bases for pathogenesis. Extensive disruption in circadian function is known to occur among schizophrenia patients. If circadian dysfunction can be established as an 'endophenotype' for schizophrenia, it may not only enable the identification of more homogenous sub-groups, but also facilitate the genetic analyses. Therefore, circadian dysfunction maybe underlies the pathogenesis of schizophrenia and would be logical to investigate polymorphisms of genes encoding key proteins that mediate circadian rhythms. Cryptochrome1 (Cry1), located in a chromosomal region 12q23-q24.1, performs predominantly regulatory function in circadian clock and which is close to a linkage hotspot (12q24) of schizophrenia. Recent studies also found that Cry1 gene interacted with antipsychotic drugs and dopamine system which played a core role in the pathophysiology of schizophrenia. Based on these findings, we speculate that Cry1 was the candidate gene of schizophrenia. The proposition may have new clues on the development of genetic study on complex diseases.

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

OBJECTIVE

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

METHOD

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

RESULTS

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

CONCLUSIONS

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

Hormonal Profile Effects Following Dehydroepiandrosterone (DHEA) Administration to Schizophrenic Patients

Dehydroepiandrosterone (DHEA) is an important neurosteroid and has demonstrated efficacy in the improvement of mood and energy. The authors previously reported the efficacy of DHEA augmentation in the management of negative, depressive, and anxiety symptoms of schizophrenia. To characterize further the effects of DHEA administration and to describe any hormonal effects following DHEA augmentation of antipsychotic medication, several hormones were measured (TSH, prolactin, testosterone, insulin, and estradiol) in 27 chronic schizophrenic inpatients receiving DHEA or placebo augmentation for 6 weeks. No significant changes in hormonal blood measures were noted. At the study end point, an association was noted between DHEA-S and TSH levels (P < 0.05) as well as a change in DHEA-S and insulin levels (P < 0.001). A modest nonsignificant decrease in plasma testosterone was observed following DHEA treatment. In subjects receiving DHEA, change in testosterone levels was associated with improvement in anxiety (P < 0.05) and illness severity (P < 0.05). Findings in this preliminary study demonstrate minimal effects on hormonal profiles despite the theoretic possibility that DHEA may elevate various hormones (eg, testosterone) with potential long-term adverse effects. DHEA's clinical efficacy appears to be mediated by other mechanisms, including direct effects on membrane channel-coupled receptors.

Circadian phase variation in bipolar I disorder

Abnormalities in circadian rhythms are prominent features of bipolar I disorder (BD1). To investigate circadian variation in BD1, we evaluated morningness-eveningness (M/E), a stable trait reflecting circadian phase, using the composite scale (CS) among BD1 patients (DSM IV criteria; n = 75), unscreened controls (n = 349), and patients with schizophrenia (SZ) or schizoaffective disorder (SZA) (n = 81). Our analyses showed that CS scores correlated significantly with age but did not differ by gender among the controls. BD1 patients differed significantly from controls and from SZ/SZA patients when age was considered. CS scores were distributed bi-modally among BD1 cases. There are several possible reasons for the observed heterogeneity. Younger BD1 patients, and those with rapid mood swings, were significantly more likely to have lower CS scores (i.e., to score in the 'evening' range and to have later circadian phase). CS scores were also positively correlated with the age at onset and the duration of the most severe depressive episodes. These relationships were not observed among the SZ/SZA groups. Thus, distinct patterns of M/E were noted among BD1 patients and among BD1 subgroups. The impact of medication, mood state, and chronicity on CS scores needs to be considered.

Male patients with paranoid schizophrenia have greater ACTH and cortisol secretion in response to metoclopramide-induced AVP release

Dynamic testing of the hypothalamic-pituitary-adrenal axis in schizophrenia has yielded conflicting results, which may be related to patient selection and previous exposure to psychotropic medication. The objective of this study was to determine the pattern of corticotropin (ACTH) and cortisol release in response to metoclopramide (a dopamine antagonist), which appears to be unique in its ability to release vasopressin (AVP), in drug naive patients with schizophrenia experiencing their first episode of psychosis. In this study, we examined AVP, ACTH and cortisol release in response to metoclopramide in 10 drug-naive, first-episode male patients with a DSM IV diagnosis of paranoid schizophrenia and compared them to healthy control subjects matched for age, sex and smoking status. Patients, as compared to controls had higher levels of baseline plasma cortisol (375.5+/-47.4/l vs. 273.8+/-42.2 nmol/l, respectively; t=2.48, df=9, p< 0.02) and plasma ACTH (14.9+/-0.85 vs. 11.3+/-0.57 pg/ml, respectively; t=4.29, df=9, p<0.001). AVP levels were lower in patients though this did not reach statistical significance (0.89+/-0.09 vs. 1.3+/-0.08 pmol/l, respectively; t=1.97, df=9, p<0.07). A repeated measures 2-way ANOVA to compare responses to metoclopramide over time between the two groups yielded a significant group by time interaction for cortisol (F=11.3, df=6, 108, p<0.001) and ACTH (F=15.65, df=6, 108, p<0.002). Post hoc Tukey's test revealed significant differences between the two groups at +30, +45, +60, +90 and +120 min for cortisol (p<0.01) and at +30, +45, +60 and +90 min for ACTH (p<0.01). The group by time interactions continued to remain significant when cortisol (F=10.9, df=6, 107, p<0.001) and ACTH (F=13.04, df=6, 108, p<0.002) were entered as co-variates. There was a significant positive correlation between AVP and cortisol responses in patients (r=0.65, df=8, p<0.01). Male patients with paranoid schizophrenia release greater amounts of ACTH and cortisol in responses to metoclopramide-induced AVP secretion than control subjects.

Antipsychotic-induced hyperprolactinaemia: mechanisms, clinical features and management

Hyperprolactinaemia is an important but neglected adverse effect of antipsychotic medication. It occurs frequently with conventional antipsychotics and some atypical antipsychotics (risperidone and amisulpride) but is rare with other atypical antipsychotics (aripiprazole, clozapine, olanzapine, quetiapine, ziprasidone). For this reason the terms 'prolactin-sparing' and 'prolactin-raising' are more useful than 'atypical' and 'conventional' when considering the effect of antipsychotic drugs on serum prolactin. During antipsychotic treatment prolactin levels can rise 10-fold or more above pretreatment values. In a recent study approximately 60% of women and 40% of men treated with a prolactin-raising antipsychotic had a prolactin level above the upper limit of the normal range. The distinction between asymptomatic and symptomatic hyperprolactinaemia is important but is often not made in the literature. Some symptoms of hyperprolactinaemia result from a direct effect of prolactin on target tissues but others result from hypogonadism caused by prolactin disrupting the normal functioning of the hypothalamic-pituitary-gonadal axis. Symptoms of hyperprolactinaemia include gynaecomastia, galactorrhoea, sexual dysfunction, infertility, oligomenorrhoea and amenorrhoea. These symptoms are little researched in psychiatric patients. Existing data suggest that they are common but that clinicians underestimate their prevalence. For example, well conducted studies of women treated with conventional antipsychotics have reported prevalence rates of approximately 45% for oligomenorrhoea/amenorrhoea and 19% for galactorrhoea. An illness-related under-function of the hypothalamic-pituitary-gonadal axis in female patients with schizophrenia may also contribute to menstrual irregularities. Long-term consequences of antipsychotic-related hypogonadism require further research but are likely and include premature bone loss in men and women. There are conflicting data on whether hyperprolactinaemia is associated with an increased risk of breast cancer in women. In patients prescribed antipsychotics who have biochemically confirmed hyperprolactinaemia it is important to exclude other causes of prolactin elevation, in particular tumours in the hypothalamic-pituitary area. If a patient has been amenorrhoeic for 1 year or more, investigations should include bone mineral density measurements. Management should be tailored to the individual patient. Options include reducing the dose of the antipsychotic, switching to a prolactin-sparing agent, prescribing a dopamine receptor agonist and prescribing estrogen replacement in hypoestrogenic female patients. The efficacy and risks of the last two treatment options have not been systematically examined. Antipsychotic-induced hyperprolactinaemia should become a focus of interest in the drug treatment of psychiatric patients, particularly given the recent introduction of prolactin-sparing antipsychotics. Appropriate investigations and effective management should reduce the burden of adverse effects and prevent long-term consequences.

Evidence of basal pituitary-adrenal overactivity in first episode, drug naïve patients with schizophrenia

BACKGROUND

Evidence for basal hypothalamic-pituitary-adrenal (HPA) axis dysfunction in schizophrenia is less consistent than that seen in major depression. Potential reasons include sampling procedures and the use of patients on antipsychotic medications which may suppress the HPA axis. Therefore, the objective of this study was to determine whether first episode, drug naïve patients with schizophrenia have evidence of basal HPA axis dysfunction by measuring plasma levels of AVP, ACTH and cortisol from 13:00 to 16:00 h, a time frame which is believed to reflect 24 h concentrations of HPA axis activity.

METHOD

In this cross-sectional study, plasma levels of AVP, ACTH and cortisol were measured in 12 (7 males and 5 females) (mean age +/-SD=33.6+/-12.6 years) patients with DSM-IV schizophrenia and compared with those found in age- and sex-matched healthy controls.

RESULTS

Patients and controls did not differ in terms of their 13:00 h cortisol and AVP. However, patients with schizophrenia had higher levels of ACTH as compared to control subjects at 13:00 h (41.3+/-14.6 vs. 12.4+/-1.1 pg/ml respectively; t=1.99, df=11, p <0.05). In comparison to controls subjects, patients with schizophrenia, had higher mean (+/-SE) AUC of ACTH (26.3+/-6.2 vs. 13.9 nmol/l, respectively; t=2.86, df=11, p <0.02) and cortisol (279.4+/-26.0 vs. 213.1+/-18.4 nmol/l, respectively; t=3.72, df=11, p <0.01). Though, patients with schizophrenia, in comparison to control subjects, had lower mean (+/-SE) AUC of AVP (0.87+/-0.24 vs. 1.42+/-0.34 pmol/l, respectively; t=2.29, df=11, p <0.02).

CONCLUSIONS

First episode, drug naïve patients with schizophrenia show evidence of basal overactivity of the pituitary-adrenal axis.

24-h Monitoring of plasma norepinephrine, MHPG, cortisol, growth hormone and prolactin in depression

Depression is associated with alterations in hormone and catecholamine circadian rhythms. Analysis of these alterations has the potential to distinguish between three neurobiological models of depression, the catecholamine model, the phase advance model and the dysregulation model. Although a number of studies of 24-h rhythms have been reported, inconsistencies among the findings have complicated efforts to model the chronobiology of depression. The present study takes advantage of frequent plasma sampling over the 24-h period and a multioscillator cosinor model to fit the 24-h rhythms.

METHOD

Plasma levels of norepinephrine, cortisol, prolacatin and growth hormone were sampled at 30-min intervals, and MHPG at 60-min intervals, over a 24-h period in 22 patients with major depressive disorder and 20 healthy control volunteers.

RESULTS

The depressed patients had phase advanced circadian rhythms for cortisol, norepinephrine and MHPG, phase advanced hemicircadian rhythms for cortisol and prolactin, and a phase advanced ultradian rhythm for prolactin compared to healthy control subjects. In addition, the rhythm-corrected 24-h mean value (mesor) of norepinephrine was lower in the depressed patients compared to the healthy controls. There also was a poorer goodness-of-fit for norepinephrine to the circadian oscillator in the depressed patients relative to the healthy controls.

CONCLUSIONS

These findings provide partial support for the dysregulation model of depression and are consistent with those studies that have found phase advances in cortisol, norepinephrine and MHPG rhythms in depression.

Layer upon layer: thermoregulation in schizophrenia

A review of the relevant published literature regarding disorders of thermoregulation in people with schizophrenia was undertaken. This entailed a search of the Medline and PsychINFO databases to 28th May 2003 using the search terms "schizophrenia and thermoregulation" and "schizophrenia and temperature". The relevant articles as well as secondary references were reviewed. It has generally been shown that, when compared with controls, people with schizophrenia exhibit dysregulation of body temperature including different baseline temperatures; abnormal daily range of temperatures and diurnal variation showing an earlier peak; an impaired ability to compensate to heat stress; and compensating more effectively to cold stress. This may be intrinsic to the syndrome of schizophrenia but is potentially confounded by the administration of neuroleptic medication. The underlying cause is likely to be a combination of "peripheral" and "central" mechanisms of thermoregulation. Further study is required to delineate clearly the quality and magnitude of the temperature dysregulation as well as elucidating its mechanism(s). This could further our understanding of the mechanism underlying the syndrome of schizophrenia.

Metabolic disturbance in first-episode schizophrenia

BACKGROUND

Schizophrenia shortens life, e.g. through suicide and obesity-related diseases such as type 2 diabetes mellitus. It is assumed that medications play a major role, but most of the evidence for this comes from studies poorly controlled for variables such as lifestyle and medication status.

AIMS

To determine whether schizophrenia is associated (independently of medication) with the development of certain metabolic disturbances and whether these might be explained by stress axis dysfunction.

METHOD

Literature review.

RESULTS

Most studies did not control for confounding factors such as previous usage of medication, lifestyle, age and ethnicity. A few conducted in drug-naïve patients with first-episode schizophrenia appear to indicate that these patients have higher than expected rates of visceral obesity and impaired fasting glucose concentrations, which may be related to a subtle disturbance of the hypothalamic-pituitary-adrenal axis.

CONCLUSIONS

Schizophrenia is independently associated with physical illnesses that have a metabolic signature. Therefore, patients need to have a thorough physical assessment at diagnosis and at regular intervals thereafter. Metabolic disturbances have been found in drug-naïve patients with first-episode illness and may be an inherent part of the illness.

Effects of estrogen on brain development and neuroprotection--implications for negative symptoms in schizophrenia

Increasing evidence during the last few years suggests that there are gender-specific differences in schizophrenia, influencing the age of onset, treatment outcome and the prevalence of negative symptoms. With respect to the latter in postmortem brain and cerebrospinal fluid of schizophrenic patients with negative symptoms a reduction of dopaminergic activity became evident. Measures of noradrenergic activity, dopamine beta-hydroxylase and the metabolite MHPG, appear to decrease with brain atrophy seen in patients with negative symptoms. Serotonergic activity tends to be low in patients with impaired cognitive function as is seen in negative schizophrenia. In these patients ventricular enlargement is associated with the severity of negative symptoms, low monoamine activity and low cerebral glucose metabolism. On the other hand atypical antipsychotic drugs that modulate also glutamate receptor activity, suggest an additional alternative mechanism of antipsychotic action beyond aminergic neurotransmitters. These drugs improve glutamatergic transmission and decrease negative symptoms; this suggests a glutamatergic deficiency as an extension of the dopamine model. The glutamate-dopamine interaction illustrates the importance of cross-talk between projections to the cortex, striatum, and lower brainstem for the expression of negative symptomatology. On the other hand, estradiol-17beta the most potent female sex hormone influences not only primary and secondary sexual characteristics but also embryonal and fetal growth as well as development of the brain aminergic networks, which are involved in schizophrenia. Estradiol-l7beta possesses neuroprotective properties, which are relevant for the course of schizophrenia and this may explain the pronounced gender differences with respect to progression and therapeutic response of schizophrenia. The present review attempts an update and synthesis of the information about the hormonal influence on neuronal pathways in negative symptoms of schizophrenia. It shows that estradiol-l7beta influences transporters and receptors as well as the morphological appearance of neuronal systems and that it may be an integral part of the neuroprotective system ameliorating schizophrenia.

Antipsychotic-induced hyperprolactinaemia in women: pathophysiology, severity and consequences. Selective literature review

BACKGROUND

Hyperprolactinaemia has for decades been an inevitable and neglected side-effect of antipsychotic medication. The recent introduction of prolactin-sparing antipsychotic agents makes a re-examination of this problem timely.

AIMS

To review the literature on antipsychotic-induced hyperprolactinaemia and its consequences.

METHOD

A search was made of the Medline database (1966-2002) for key articles, supplemented by cross-referencing.

RESULTS

During antipsychotic treatment prolactin concentrations can rise to ten times normal levels or above, and existing data indicate that 17-78% of female patients have amenorrhoea with or without galactorrhoea. Survey data, however, suggest that clinicians underestimate the prevalence of these conditions. Long-term consequences of antipsychotic-related hypo-oestrogenism require further research but are likely to include premature bone loss.

CONCLUSIONS

Antipsychotic-induced hyperprolactinaemia should become a focus of interest in the drug treatment of psychiatric patients.

Stress in schizophrenia: an integrative view

Stress and the development of a (schizophrenic) psychosis are inextricably related. The process by which stress actually affects psychosis is far less clear. The hypothalamic-pituitary-adrenal system, and in particular the release of corticosteroids, has been attributed an essential role. However, schizophrenia is a disorder in which many functions are distorted. Dysfunctions can be found in behavior, cognition, coping, physiology, pituitary-adrenal and immune functioning. In this short paper, these functions are discussed as to how they contribute to the way stress is appraised and processed. Schizophrenic patients are impaired in their biological response to stress by showing a blunted cortisol response to psychosocial stress. It is hypothesized that this reflects rather cognitive dysfunction, based on biological dysfunctions in those brain structures that are responsible for these processes, i.e. the prefrontal cortex and the limbic system. Considering the blunted cortisol response as a maladaptive stress response, its consequences are commented on with an emphasis on the immune system. Finally, the role of neuroleptics, and in particular the atypical ones, is discussed for their beneficial effect, beyond their fear-and anxiety-reducing properties, in restoring some of the cognitive dysfunctions schizophrenic patients display. By doing so, they may improve perception of the environment, enhance adjustment and thus a proper stress response. Integration of these processes in stress research described, may provide new vistas of the stress concept in schizophrenia.

Time of day of testing and neuropsychological performance of schizophrenic patients and healthy controls

The current project examined how time of day of neuropsychological testing influenced the performance of schizophrenic patients and healthy controls. All subjects were tested twice, once in the morning (AM) and once in the afternoon (PM), on a battery of neuropsychological tests. Testings were separated by 1week, and order of first testing (AM versus PM) was counterbalanced. Consistent with recent research, the current study found that time of day (TOD) influenced performance on most measures. However, the TOD effect differentially influenced the performance of each group. The controls showed better performance during PM (compared with AM) testings on measures of verbal memory and attention; whereas the patients showed better performance during PM (compared with AM) testings on measures of visual memory and motor speed. These results were not due to practice effects. Finally, there were trends for patient medication dosage to be associated with performance on some measures.

Diurnal variation in spontaneous eye-blink rate

The daily pattern of spontaneous eye-blink rate (BR), a non-invasive peripheral measure of central dopamine activity, was investigated in 24 healthy subjects. The spontaneous eye-blink rate showed a stable pattern in morning, midday and afternoon hours. A significant increase was found at the evening time point (20.30 h). The finding is suggestive of a late evening increase of central dopamine activity. An increased level of subjective sleepiness was also found at the same evening point, at a time corresponding to the 'evening wake maintenance zone' or the 'forbidden zone for sleep'. A possible hypothesis is that the 'forbidden zone for sleep' may reflect a dopamine-mediated activation that counteracts a rising sleep drive. The role of diurnal variation of dopamine function should be considered both in the choice of the drug treatment regimen, and in the evaluation of biological and neuropsychological parameters.

HPA axis and cytokines dysregulation in schizophrenia: potential implications for the antipsychotic treatment

The authors discuss literature evidence on the possible dysfunctioning of HPA axis and the inflammatory response system (IRS) in schizophrenia in relation to a more comprehensive bio-pathogenetic hypothesis of the disorder and to the development of specific clinical patterns or 'core' schizophrenic symptoms, like those included in the so called negative/depressive dimension. The dysfunctions of HPA axis and IRS could be linked to some neurodevelopmental damage in relevant brain areas like hippocampus and it could involve mainly the glutamatergic pathways (e.g. NMDA receptors). Moreover, these changes could have some predictive value for response to typical antipsychotics (specifically for negative symptoms and drug resistance) in schizophrenia. Finally, the differential activity of typical versus atypical antipsychotic compounds on the basic HPA axis and IRS dysregulations in schizophrenia could account, at least partly, for the better clinical stabilization achieved in patients treated with the latter drugs compared to those receiving conventional neuroleptics.

Psychoneuroendocrinology of schizophrenia

The study of psychoneuroendocrinology of schizophrenia has yielded an extensive but inconclusive body of data. Investigations to date have been limited by several factors, including the confounding effects of neuroleptic drugs, methodological limitations, and lack of appreciation for the heterogeneity of the illness. Previously, the focus of research has been on the measurement of anterior pituitary hormones, guided by the assumptions that these hormones are regulated by the central nervous system (CNS) to a significant degree and that the unique anatomic relationship of the pituitary gland to the hypothalamus and the CNS is potentially relevant. Patients with schizophrenia do appear to have distinct endocrinologic profiles. However, although the hormonal differences between patients with schizophrenia and the general population appear to be subtle in magnitude. Nonetheless, investigation, and the exploration of the possible effect of gonadal and posterior pituitary hormones merits particular attention.