Background: The suggestion that the neurohormone oxytocin may have clinical application in the treatment of schizophrenia was first published in 1972. Since then, a considerable body of research on a variety of fronts – including several recent double-blind treatment trials – has buttressed these early reports, providing support for the assertion that the oxytocin system is a promising and novel therapeutic target for this devastating malady. Herein, we review the diverse, convergent lines of evidence supporting the therapeutic potential of oxytocin in psychotic illness.

Methods: We performed a systematic review of preclinical and clinical literature pertaining to oxytocin's role in schizophrenia.

Results: Multiple lines of evidence converge to support the antipsychotic potential of oxytocin. These include several animal models of schizophrenia, pharmacological studies examining the impact of antipsychotics on the oxytocin system, human trials in patients examining the aspects of the oxytocin system and several double-blind, placebo-controlled clinical treatment trials.

Conclusions: There exists considerable, convergent evidence that oxytocin has potential as a novel antipsychotic with a unique mechanism of action. Auspiciously, based on the few chronic trials to date, its safety profile and tolerability appear very good. That said, several critical clinical questions await investigation before widespread use is clinically warranted.

Objective: Alexithymia refers to an ineffective regulation and expression of emotions. It constitutes a major risk factor for a range of medical and psychiatric problems, including chronic pain, somatisation, anxiety and depression. Alexithymia is a multi-faceted concept, described in terms of cognitive and affective aspects. From a neuropsychological perspective, alexithymia can be defined as a disturbance in affective information processing and social cognition. As the growing literature on brain structures involved in alexithymia is fragmented and sometimes even contradictory, the aim of this article was to review findings on neural substrates with regard to their convergence.

Methods: A narrative review was performed, including both early neuropsychological and more recent imaging studies, in order to achieve a better understanding of the aetiology of alexithymia.

Results: Corpus callosum, cingulate cortex and insula are clearly involved in alexithymia. The amygdala and the orbitofrontal part of the cortex appear to be implicated as mediators, because of their broader involvement in emotional processing and executive control.

Conclusion: Notwithstanding the diffuse neural representation, the alexithymia construct can be usefully applied in the clinical and empirical studies of social cognition, particularly when adopting a dimensional neuropsychological approach.

Objective: The mechanisms involved in the dysregulation of the hypothalamic–pituitary–adrenal (HPA) axis, especially in the functioning of glucocorticoid receptor (GR) and mineralocorticoid receptor (MR) in depressed patients, are not well elucidated. The objective of this study was to conduct a systematic review of articles that assess the HPA axis activity from GR and MR in depressed patients and healthy controls with or without early life stress.

Methods: We conducted a systematic review of articles in PubMed, SCOPUS and SciELO published between 2000 and 2011, using the following search terms: child abuse, depression, HPA axis, dexamethasone, prednisolone, fludrocortisone and spironolactone. Thirty-four papers were selected for this review.

Results: Most studies identified in this review used the dexamethasone/corticotropin-releasing hormone test and dexamethasone suppression test. In these studies, hypercortisolaemia was associated with depression. We identified three studies with the Prednisolone suppression test, only one study with the use of fludrocortisone and one with spironolactone. This review found nine studies that evaluated the HPA axis in individuals with early life stress.

Conclusions: The majority of the studies assessed in this review show that early life stress leads to permanent changes in the HPA axis and may lead to development of depression in adults. The most consistent findings in the literature show increased activity of the HPA axis in depression associated with hypercortisolaemia and reduced inhibitory feedback. These findings suggest that this dysregulation of the HPA axis is partially attributable to an imbalance between GR and MR. Evidences have consistently showed that GR function is impaired in major depression, but few studies have assessed the activity of MR in depression and early life stress.

Objective: Considering that mitochondria may be drug targets and some characteristics of drug–mitochondria interactions may still be misjudged because of the difficulty in foreseeing and understanding all possible implications of the complex pathophysiology of mitochondria, our study aimed to investigate the effect of escitalopram on the activity of enzymes of mitochondrial energy metabolism.

Methods: Animals received daily administration of escitalopram dissolved in saline [10 mg/kg, intraperitoneal (IP)] at 1.0 ml/kg volume for 14 days. Control rats received an equivalent volume of saline, 1.0 ml/kg (IP), for the same treatment period. Twelve hours after last injection, rats were killed by decapitation and brain areas were rapidly isolated. The samples were homogenised and the activities of mitochondrial respiratory chain complexes, some enzymes of Krebs cycle (citrate synthase, malate dehydrogenase and succinate dehydrogenase) and creatine kinase were measured.

Results: We verified that chronic administration of escitalopram decreased the activities of complexes I and II–III in cerebellum, hippocampus, striatum and posterior cortex whereas prefrontal cortex was not affected. Complex II activity was decreased only in striatum without affecting prefrontal cortex, hippocampus, cerebellum and posterior cortex. However, chronic administration of escitalopram did not affect complex IV and enzymes of Krebs cycle activities as well as creatine kinase.

Conclusion: In this study we showed a decrease in the activities of complexes I and II–III in most of the brain structures analysed and complex II activity was decreased only in striatum. However, it remains to be determined if mitochondrial dysfunction is rather a causal or a consequential event of abnormal signalling.

Objective: There is clear evidence of a genetic component in major depression, and several studies indicate that neuropeptide Y (NPY) could play an important role in the pathophysiology of the disease. A well-known polymorphism encoding the substitution of leucine to proline in the signal peptide sequence of NPY (Leu7Pro variation) was previously found to protect against depression. Our study aimed at replicating this association in a large Danish population with major depression.

Method: Leu7Pro was studied in a sample of depressed patients and ethnically matched controls, as well as psychiatric disease controls with schizophrenia. Possible functional consequences of Leu7Pro were explored in vitro.

Results: In contrast to previous studies, Pro7 appeared to be a risk allele for depression, being significantly more frequent in the depression sample (5.5%, n = 593; p = 0.009; odds ratio, OR: 1.46) as compared to ethnically matched controls (3.8%, n = 2912), while schizophrenia patients (4.1%, n = 503) did not differ. In vitro, the Pro7 substitution appeared to be associated with reduced levels of NPY without affecting its mRNA level.

Conclusion: The Leu7Pro variation may increase the risk of major depression, possibly by affecting the biosynthesis of NPY.

Background: The last few decades have seen a renaissance in the development of neuropsychiatric services on a global scale.

Methods: This paper reviews the existing literature on the changing role of the clinical neuropsychiatrist and discusses the evolving theory and practice of neuropsychiatry in the United Kingdom.

Results: The rapidly evolving specialty of neuropsychiatry is currently facing a number of challenges. These include, but are not limited to, uncertainties about the curricular requirements for clinical neuropsychiatrists and the changing roles within the wider scenario of health-care service provision.

Discussion: An informed historical perspective on this multifaceted discipline allows key insights into its future development.

Objective: Deficits in adult and embryonic neurogenesis have been linked with neurological and psychiatric disorders, so it is important to understand the molecular mechanisms underlying this process. SOX11 is a transcription factor known to play a critical role in the regulation of the neuronal and glial differentiation stage of neurogenesis, so we hypothesised that the identification of its target genes would reveal underlying biological processes relevant to disease.

Methods: SOX11 protein was over-expressed in HEK293 cells and transcriptional changes assessed by microarray analysis. Selected candidate genes were further tested for SOX11 activation in quantitative reverse transcriptase PCR studies of HEK293 cells and Western analysis of SH-SY5Y cells.

Results: Regulated genes included a previously established SOX11 target, known markers of neurogenesis, as well as several genes implicated in neuropsychiatric disorders. Immunofluorescence localised several of the genes within the proliferative subgranular zone of the hippocampus. We observed multiple histone and zinc finger genes regulated by SOX11, many of which were located in two clusters on chromosomes 6 and 19. The chromosome 6 cluster lies within a region of the genome showing the strongest genetic association with schizophrenia.

Conclusion: SOX11 appears to regulate a complex programme of chromatin remodelling and downstream gene expression changes to achieve a mature neuronal phenotype. SOX11 target genes are shown to be involved in neurodevelopmental processes important in health and, potentially, disease.

Objective: Causative relations between infections and psychosis, especially schizophrenia, have been speculated for more than a century, suggesting a hypothesis of association between schizophrenia and hereditary immune defects. Mannan-binding lectin (MBL) is a pattern-recognition molecule of the innate immune defence. MBL deficiency is the most common hereditary defect in the immune system and may predispose to infection and autoimmunity. Mannan-binding lectin serine protease-2 (MASP-2) is an MBL-associated serine protease mediating complement activation upon binding of MBL/MASP to microorganisms. The objective was to investigate if schizophrenia is associated with serum concentrations of MBL and MASP-2 or with genetic variants of the genes MBL2 and MASP2 encoding these proteins.

Methods: The sample consisted of 100 patients with schizophrenia and 350 controls. Concentrations of MBL and MASP-2 in serum were measured and seven single nucleotide polymorphisms known to influence these concentrations were genotyped.

Results: Significant association of disease with genetic markers was found in MBL2 but not in MASP2. Significant difference in MBL serum concentration was found between patients and controls when adjusting for MBL2 haplotypes. For concentrations of MASP-2, a significant interaction effect between a MASP2 variant and disease was found. Interestingly, MASP-2 levels also depended significantly on variants in MBL2 exon 1.

Conclusion: This study supports previous studies showing increased complement activity in patients with schizophrenia, indicates aetiological heterogeneity among patients and underlines that multilocus genotypes have to be considered when investigating effects on MBL level. It appears that inclusion of additional components from the system of complement activation is warranted.