Schizophrenia (SZ) is a complex brain disorder linked to cognitive and neurostructural abnormalities that involves genetic and environmental factors with obstetric complications (OCs) at birth conferring a high risk for the disease. Indeed, current research in the general population describes the deleterious effect of OCs on cognitive performance in adulthood. With this rationale, we aim to review the relationship between OCs and cognition in SZ and related psychotic disorders.

A systematic review and meta-analysis describing cognitive function and OCs in patients with SZ and related disorders were conducted. PubMed, EmBase, SCOPUS, and the Cochrane Library were systematically searched to identify eligible studies up to January 2022. We calculated the effect sizes (Hedges' g) of cognitive domains within each study and quantified the proportion of between-study variability using the I2 statistic. Homogeneity was assessed using the Q-statistic (X2). The study was registered on PROSPERO (CRD42018094238).

A total of 4124 studies were retrieved, with 10 studies meeting inclusion criteria for the systematic review and eight for meta-analysis. SZ subjects with OCs showed poor verbal memory [Hedges' g = −0.89 (95% CI −1.41 to −0.37), p < 0.001] and working memory performance [Hedges' g = −1.47 (95% CI −2.89 to −0.06), p = 0.01] in a random-effect model compared to those without OCs.

OCs appear to have a moderate impact on specific cognitive such as working memory and verbal memory. Our findings suggest that OCs are associated with brain development and might underlie the cognitive abnormalities described at onset of psychosis.

Cognition heavily relies on social determinants and genetic background. Latin America comprises approximately 8% of the global population and faces unique challenges, many derived from specific demographic and socioeconomic variables, such as violence and inequality. While such factors have been described to influence mental health outcomes, no large-scale studies with Latin American population have been carried out. Therefore, we aim to describe the cognitive performance of a representative sample of Latin American individuals with schizophrenia and its relationship to clinical factors. Additionally, we aim to investigate how socioeconomic status (SES) relates to cognitive performance in patients and controls.

We included 1175 participants from five Latin American countries (Argentina, Brazil, Chile, Colombia, and Mexico): 864 individuals with schizophrenia and 311 unaffected subjects. All participants were part of projects that included cognitive evaluation with MATRICS Consensus Cognitive Battery and clinical assessments.

Patients showed worse cognitive performance than controls across all domains. Age and diagnosis were independent predictors, indicating similar trajectories of cognitive aging for both patients and controls. The SES factors of education, parental education, and income were more related to cognition in patients than in controls. Cognition was also influenced by symptomatology.

Patients did not show evidence of accelerated cognitive aging; however, they were most impacted by a lower SES suggestive of deprived environment than controls. These findings highlight the vulnerability of cognitive capacity in individuals with psychosis in face of demographic and socioeconomic factors in low- and middle-income countries.

Social and environmental factors such as poverty or violence modulate the risk and course of schizophrenia. However, how they affect the brain in patients with psychosis remains unclear.

We studied how environmental factors are related to brain structure in patients with schizophrenia and controls in Latin America, where these factors are large and unequally distributed.

This is a multicentre study of magnetic resonance imaging in patients with schizophrenia and controls from six Latin American cities. Total and voxel-level grey matter volumes, and their relationship with neighbourhood characteristics such as average income and homicide rates, were analysed with a general linear model.

A total of 334 patients with schizophrenia and 262 controls were included. Income was differentially related to total grey matter volume in both groups (P = 0.006). Controls showed a positive correlation between total grey matter volume and income (R = 0.14, P = 0.02). Surprisingly, this relationship was not present in patients with schizophrenia (R = −0.076, P = 0.17). Voxel-level analysis confirmed that this interaction was widespread across the cortex. After adjusting for global brain changes, income was positively related to prefrontal cortex volumes only in controls. Conversely, the hippocampus in patients with schizophrenia, but not in controls, was relatively larger in affluent environments. There was no significant correlation between environmental violence and brain structure.

Our results highlight the interplay between environment, particularly poverty, and individual characteristics in psychosis. This is particularly important for harsh environments such as low- and middle-income countries, where potentially less brain vulnerability (less grey matter loss) is sufficient to become unwell in adverse (poor) environments.

This study aimed to explore effects of adjunctive treatment with N-acetyl cysteine (NAC) on markers of inflammation and neurogenesis in bipolar depression.

This is a secondary analysis of a placebo-controlled randomised trial. Serum samples were collected at baseline, week 8, and week 32 of the open-label and maintenance phases of the clinical trial to determine changes in interleukin (IL)-6, IL-8, IL-10, tumour necrosis factor-α (TNF-α), C-reactive protein (CRP) and brain-derived neurotrophic factor (BDNF) following adjunctive NAC treatment, and to explore mediation and moderator effects of the listed markers.

Levels of brain-derived neurotrophic factor (BDNF), tumour necrosis factor-α (TNF-α), C-reactive protein (CRP), interleukins (IL) -6, 8, or 10 were not significantly changed during the course of the trial or specifically in the open-label and maintenance phases. There were no mediation or moderation effects of the biological factors on the clinical parameters.

The results suggest that these particular biological parameters may not be directly involved in the therapeutic mechanism of action of adjunctive NAC in bipolar depression.

To evaluate the effect of N-acetylcysteine (NAC) on substance use in a double-blind, placebo-controlled trial of NAC in bipolar disorder. It is hypothesised that NAC will be superior to placebo for reducing scores on the Clinical Global Impressions scale for Substance Use (CGI-SU).

Participants were randomised to 6-months of treatment with 2 g/day NAC (n = 38) or placebo (n = 37). Substance use was assessed at baseline using the Habits instrument. Change in substance use was assessed at regular study visits using the CGI-SU.

Amongst the 75 participants 78.7% drank alcohol (any frequency), 45.3% smoked tobacco and 92% consumer caffeine. Other substances were used by fewer than six participants. Caffeine use was significantly lower for NAC-treated participants compared with placebo at week 2 of treatment but not at other study visits.

NAC appeared to have little effect on substance use in this population. A larger study on a substance using population will be necessary to determine if NAC may be a useful treatment for substance use.

There is a paucity of data about risk factors for suicide attempts in bipolar disorder. The aim of this study is to examine the association between suicide attempts and obesity in people with bipolar disorder.

Two hundred fifty-five DSM-IV out-patients with bipolar disorder were consecutively recruited from the Bipolar Disorder Program at Hospital das Clínicas de Porto Alegre and the University Hospital at the Universidade Federal de Santa Maria, Brazil. Diagnosis and clinical variables were assessed with Structured Clinical Interview for DSM-IV-axis I (SCID I) and Program structured protocol. History of suicide attempts was obtained from multiple information sources including patients, relatives and review of medical records. Patients with body mass index (BMI) ≥ 30 were classified as obese.

Over 30% of the sample was obese and over 50% had a history of suicide attempt. In the multivariate model, obese patients were nearly twice (OR = 1.97, 95% CI: 1.06–3.69, p = 0.03) as likely to have a history of suicide attempt(s).

Our results emphasise the relevance of obesity as an associated factor of suicide attempts in bipolar disorder. Obesity may be seen as correlate of severity and as such, must be considered in the comprehensive management of bipolar patients.

To evaluate the effect of N-acetylcysteine (NAC) on substance use in a double-blind, placebo-controlled trial of NAC in bipolar disorder. It is hypothesised that NAC will be superior to placebo for reducing scores on the Clinical Global Impressions scale for Substance Use (CGI-SU).

Participants were randomised to a 6-months of treatment with 2 g/day NAC (n = 38) or placebo (n = 37). Substance use was assessed at baseline using a Habits instrument. Change in substance use was assessed at regular study visits using the CGI-SU.

Among the 75 participants 78.7% drank alcohol (any frequency), 45.3% smoked tobacco and 92% consumed caffeine. Other substances were used by fewer than six participants. Caffeine use was significantly lower for NAC-treated participants compared to placebo at week 2 of treatment but not at other study visits.

NAC appeared to have little effect on the participants who were using substances. A larger study on a substance-using population will be necessary to determine if NAC may be a useful treatment for substance use.

The dimensional approach of the obsessive-compulsive symptoms may help to find more homogeneous groups of patients. The brain derived neurotrophic factor (BDNF) may help to identify neurobiological differences between obsessive-compulsive symptom dimensions.

We compared serum BDNF (pg/μg) levels of 25 unmedicated patients meeting Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria for obsessivecompulsive disorder (OCD) and 25 controls, using the Dimensional Yale‐Brown Obsessive‐Compulsive Scale, the Yale‐Brown Obsessive‐Compulsive Scale and the Beck's Anxiety and Depression Inventories.

There were no sociodemographic differences between the groups. The standard error of mean serum BDNF levels were reduced in unmedicated OCD patients (0.47+0.038) when compared to healthy controls (0.75+0.060) (P<.001). The patients with the presence of sex/religion obsessive-compulsive symptoms (OCS) dimension (P=.002), with chronic course of OCS (P=.022) and the presence of lifetime major depression (P=.016) and social anxiety (P=.030) presented higher levels of BDNF than OCD patients without those features. The severity of aggression (P=.039) and sex/religion (P<.001) OCS dimension presented direct (moderate and strong, respectively) correlation with serum BDNF levels in this sample. Serum BDNF levels were decreased in OCD patients when compared to healthy controls.

Sexual and religious content of symptoms and aggression and sex/religion dimensions severity should be better explored, since these specific OCS dimensions could be based on neurocircuits diverse from those of the other OCS dimensions.