Sex differences in cognitive functioning of patients at-risk for psychosis and healthy controls: Results from the European Gene-Environment Interactions study.

BACKGROUND: Sex differences in cognitive functioning have long been recognized in schizophrenia patients and healthy controls (HC). However, few studies have focused on patients with an at-risk mental state (ARMS) for psychosis. Thus, the aim of the present study was to investigate sex differences in neurocognitive performance in ARMS patients compared with HC. METHODS: The data analyzed in this study were collected within the multicenter European Gene-Environment Interactions study (11 centers). A total of 343 ARMS patients (158 women) and 67 HC subjects (33 women) were included. All participants completed a comprehensive neurocognitive battery. Linear mixed effects models were used to explore whether sex differences in cognitive functioning were present in the total group (main effect of sex) and whether sex differences were different for HC and ARMS (interaction between sex and group). RESULTS: Women performed better in social cognition, speed of processing, and verbal learning than men regardless of whether they were ARMS or HC. However, only differences in speed of processing and verbal learning remained significant after correction for multiple testing. Additionally, ARMS patients displayed alterations in attention, current IQ, speed of processing, verbal learning, and working memory compared with HC. CONCLUSIONS: Findings indicate that sex differences in cognitive functioning in ARMS are similar to those seen between healthy men and women. Thus, it appears that sex differences in cognitive performance may not be specific for ARMS, a finding resembling that in patients with schizophrenic psychoses.

Gender differences of patients at-risk for psychosis regarding symptomatology, drug use, comorbidity and functioning - Results from the EU-GEI study.

BACKGROUND: Gender differences in symptomatology in chronic schizophrenia and first episode psychosis patients have often been reported. However, little is known about gender differences in those at risk of psychotic disorders. This study investigated gender differences in symptomatology, drug use, comorbidity (i.e. substance use, affective and anxiety disorders) and global functioning in patients with an at-risk mental state (ARMS) for psychosis. METHODS: The sample consisted of 336 ARMS patients (159 women) from the prodromal work package of the EUropean network of national schizophrenia networks studying Gene-Environment Interactions (EU-GEI; 11 centers). Clinical symptoms, drug use, comorbidity and functioning were assessed at first presentation to an early detection center using structured interviews. RESULTS: In unadjusted analyses, men were found to have significantly higher rates of negative symptoms and current cannabis use while women showed higher rates of general psychopathology and more often displayed comorbid affective and anxiety disorders. No gender differences were found for global functioning. The results generally did not change when corrected for possible cofounders (e.g. cannabis use). However, most differences did not withstand correction for multiple testing. CONCLUSIONS: Findings indicate that gender differences in symptomatology and comorbidity in ARMS are similar to those seen in overt psychosis and in healthy controls. However, observed differences are small and would only be reliably detected in studies with high statistical power. Moreover, such small effects would likely not be clinically meaningful.

Gender differences in first self-perceived signs and symptoms in patients with an at-risk mental state and first-episode psychosis.

AIM: Gender differences in the current symptomatology of patients with psychotic disorders have previously been described in the literature. However, it has not yet been investigated whether gender differences exist in the very first self-perceived signs or symptoms of illness onset. The aim of this study was to investigate this aspect in at-risk mental state (ARMS) and first-episode psychosis (FEP) patients. METHODS: ARMS and FEP were recruited via the early detection of psychosis (FePsy) clinic Basel, Switzerland. The Basel Interview for Psychosis (BIP) was used to retrospectively assess the first 3 self-perceived signs and symptoms at illness onset. Differences between gender and patient groups on single item and symptom cluster levels were analysed using logistic regression models. RESULTS: One-hundred-thirty six ARMS (91 men, 45 women) and 89 FEP patients (63 men, 26 women) could be recruited for this study. On a single item level, women more frequently reported "unusual anxiety, fears" and men (at a trend level) "social withdrawal" as being among their 3 first self-perceived symptoms, independent of diagnostic group. On the symptom cluster level, women more frequently reported "increased worrying/anxiety" and (sub-threshold) "hallucinations", independent of diagnostic group. Problems with "thinking, concentration" were reported more frequently by men in the ARMS group only. CONCLUSION: Our results suggest that only few and relatively small gender differences exist in the first self-perceived signs and symptoms. While men initially mainly notice negative/cognitive symptoms, women first notice (sub-threshold) positive and affective symptoms.

Evaluating verbal learning and memory in patients with an at-risk mental state or first episode psychosis using structural equation modelling.

BACKGROUND: Verbal learning and memory are impaired not only in patients with a first episode of psychosis (FEP) but also-to a lower extent-in those with an at-risk mental state for psychosis (ARMS). However, little is known about the specific nature of these impairments. Hence, we aimed to study learning and memory processes in ARMS and FEP patients by making use of structural equation modelling. METHODS: Verbal learning was assessed with the California Verbal Learning Test (CVLT) in 98 FEP patients, 126 ARMS patients and 68 healthy controls (HC) as part of the Basel early detection of psychosis (FePsy) study. The four-factorial CFA model of Donders was used to estimate test performance on latent variables of the CVLT and growth curve analysis was used to model the learning curve. The latter allows disentangling initial recall, which is strongly determined by attentional processes, from the learning rate. RESULTS: The CFA model revealed that ARMS and FEP patients were impaired in Attention Span, Learning Efficiency and Delayed Memory and that FEP patients were additionally impaired in Inaccurate Memory. Additionally, ARMS-NT, but not ARMS-T, performed significantly worse than HC on Learning Efficiency. The growth curve model indicated that FEP patients were impaired in both initial recall and learning rate and that ARMS patients were only impaired in the learning rate. CONCLUSIONS: Since impairments were more pronounced in the learning rate than the initial recall, our results suggest that the lower scores in the CVLT reported in previous studies are more strongly driven by impairments in the rate of learning than by attentional processes.

Sex differences in prolactin levels in emerging psychosis: Indication for enhanced stress reactivity in women.

BACKGROUND: Hyperprolactinemia is a known side effect of antipsychotics. In recent reports it has also been shown in antipsychotic-naïve at-risk mental state (ARMS) and first-episode psychosis (FEP) patients. Prolactin is not only involved in reproduction and lactation, but is also synthesized in response to stress. As stress is thought to play an important role in the onset and relapse of schizophrenia, the aim of this study was to further elucidate the influence of prolactin in emerging psychosis. METHODS: The data analysed in this study were collected within the prospective Früherkennung von Psychosen (FePsy) study. Blood sample collection took place under standardized conditions between 8 and 10am after an overnight fast and 30minutes of rest. All patients were antipsychotic-naïve and did not take any prolactin influencing medication. RESULTS: Our sample consisted of 116 antipsychotic-naïve ARMS and 49 FEP patients. Hyperprolactinemia was shown in 32% of ARMS and 35% of FEP patients. After correction for the normal biological variation between the sexes, we still found higher average prolactin levels in female than in male patients (ß=0.42; t=2.47; p=0.01) but no difference in prolactin levels between ARMS and FEP patients (ß=-0.05; t=-0.30; p=0.76). The survival analysis revealed no significant predictive value for prolactin levels to predict transition to psychosis. CONCLUSION: Our findings support a possible role of prolactin in emerging psychosis and it could be speculated that stress, which can induce hyperprolactinemia, has a stronger effect on women than on men in emerging psychosis.