Longitudinal evidence for a relation between depressive symptoms and quality of life in schizophrenia using structural equation modeling.

Patients diagnosed with schizophrenia often report a low quality of life (QoL). The purpose of this study was to investigate whether we could replicate a cross-sectional model by Alessandrini et al. (2016, n = 271) and whether this model predicts QoL later in life. This model showed strong associations between schizophrenia spectrum symptoms and depressive symptoms on QoL, but lacked follow-up assessment. This model was adapted in the current study and the robustness was investigated by using a longitudinal design in which the association between baseline variables (including IQ, depression, schizophrenia spectrum symptoms as well as social functioning) and QoL during 3-years of follow-up was investigated. We included patients with a non-affective psychotic disorder (n = 744) from a prospective naturalistic cohort-study. In the cross-sectional model, with good measure of fit, both depression as well as social functioning was associated with QoL (direct path coefficient -0.28 and 0.41, respectively). Additionally, the severity of schizophrenia spectrum symptoms was highly associated with social functioning (direct path coefficient -0.70). Importantly, the longitudinal model showed good measures of fit, which strengthens the validity of the initial model and highlights that depression prospectively affect QoL while schizophrenia spectrum symptoms prospectively influence QoL via social functioning. The negative, longitudinal impact of a depression on QoL highlights the need to focus on treatment of this co-morbidity.

Low prevalence of substance use in people with 22q11.2 deletion syndrome.

BACKGROUND: 22q11.2 deletion syndrome (22q11DS), one of the most common recurrent copy number variant disorders, is associated with dopaminergic abnormalities and increased risk for psychotic disorders. AIMS: Given the elevated prevalence of substance use and dopaminergic abnormalities in non-deleted patients with psychosis, we investigated the prevalence of substance use in 22q11DS, compared with that in non-deleted patients with psychosis and matched healthy controls. METHOD: This cross-sectional study involved 434 patients with 22q11DS, 265 non-deleted patients with psychosis and 134 healthy controls. Psychiatric diagnosis, full-scale IQ and COMT Val158Met genotype were determined in the 22q11DS group. Substance use data were collected according to the Composite International Diagnostic Interview. RESULTS: The prevalence of total substance use (36.9%) and substance use disorders (1.2%), and weekly amounts of alcohol and nicotine use, in patients with 22q11DS was significantly lower than in non-deleted patients with psychosis or controls. Compared with patients with 22q11DS, healthy controls were 20 times more likely to use substances in general (P < 0.001); results were also significant for alcohol and nicotine use separately. Within the 22q11DS group, there was no relationship between the prevalence of substance use and psychosis or COMT genotype. Male patients with 22q11DS were more likely to use substances than female patients with 22q11DS. CONCLUSIONS: The results suggest that patients with 22q11DS are at decreased risk for substance use and substance use disorders despite the increased risk of psychotic disorders. Further research into neurobiological and environmental factors involved in substance use in 22q11DS is necessary to elucidate the mechanisms involved. DECLARATION OF INTEREST: None.

Cognitive behavioral therapy for social activation in recent-onset psychosis: Randomized controlled trial.

OBJECTIVE: Negative symptoms largely account for poor outcome in psychotic disorders but remain difficult to treat. A cognitive-behavioral approach to these symptoms showed promise in chronic schizophrenia patients. We explored whether a combination of group and individual treatment focused on social activation (CBTsa) could benefit patients recently diagnosed with a psychotic disorder. METHOD: A single-blind randomized controlled trial enrolled 99 participants recently diagnosed with schizophrenia or a related disorder that received treatment as usual (TAU; n = 50), or TAU plus CBTsa (n = 49). Negative symptoms (Brief Negative Symptom Scale) and social withdrawal (Positive and Negative Syndrome Scale) were primary outcomes. Secondary outcome measures included dysfunctional beliefs (Dysfunctional Attitudes Scale-Defeatist Performance Attitude), stigma Internalized Stigma of Mental Illness Scale (ISMIS), and symptom severity and functioning as measured with the Global Assessment of Functioning (GAF). Outcomes were compared directly posttreatment and at follow-up (6 months posttreatment). RESULTS: Intention-to-treat analyses showed significant improvement in GAF symptoms (p = .02, d = 0.36) and a decrease in negative symptoms on trend level (p = .08, d = -0.29) in CBTsa compared to TAU at posttreatment. These group differences were no longer apparent at 6 months follow-up. Social withdrawal and negative symptoms improved over time in both conditions. CONCLUSIONS: The current trial showed small positive effects on symptom severity posttreatment but did not demonstrate maintenance of longer-term effects in favor of the CBTsa group. Findings suggest that the treatment duration may have been too short to change dysfunctional beliefs, a potentially important maintaining factor of negative symptom severity. Longer intervention periods in later, more stable stages of the illness when intensive standard treatment has tapered off may yield more beneficial effects. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Associations between olfactory identification and (social) cognitive functioning: A cross-sectional study in schizophrenia patients and healthy controls.

Schizophrenia patients have difficulties identifying odors, possibly a marker of cognitive and social impairment. This study investigated olfactory identification (OI) differences between patients and controls, related to cognitive and social functioning in childhood and adolescence, to present state cognition and to present state social cognition. 132 schizophrenia patients and 128 healthy controls were assessed on OI performance with the Sniffin' Sticks task. Multiple regression analyses were conducted investigating OI in association with cognitive and social functioning measures in childhood/adolescence and in association with IQ, memory, processing speed, attention, executive functioning, face recognition, emotion recognition and theory of mind. Patients had reduced OI performance compared to controls. Also, patients scored worse on childhood/adolescence cognitive and social functioning, on present state cognitive functioning and present state social cognition compared to controls. OI in patients and controls was significantly related to cognitive and social functioning in childhood/adolescence, to present state cognition and to present state social cognition, with worse functioning being associated with worse OI. In this study, findings of worse OI in patients relative to controls were replicated. We also showed associations between OI and cognitive and social functioning which are not specific to schizophrenia.

The role of cognitive functioning in the relationship between childhood trauma and a mixed phenotype of affective-anxious-psychotic symptoms in psychotic disorders.

Cognitive impairments in patients with psychotic disorder have been associated with poor functioning and increased symptom severity. Furthermore, childhood trauma (CT) exposure has been associated with worse cognitive functioning as well as co-occurrence of affective-anxious-psychosis symptoms or a 'mixed phenotype of psychopathology' (MP), which in turn is associated with greater symptom severity, and poor functioning. This study aims to evaluate if cognition could be associated with CT/MP. 532 patients with non-affective psychotic patients were assessed on CT, symptom profile, cognition, functioning, and symptom severity at baseline and 3 and 6-year follow-up. Four subgroups were made according to trauma exposure (CT- or CT+) and presence of a mixed phenotype (MP- or MP+): CT-/MP (n=272), CT-/MP+ (n=157), CT+/MP- (n=49), and CT+/MP+ (n=54). Mixed-effects multilevel regression, linear regression, and Tobit analyses were performed. Patients with both CT and MP showed lower verbal learning and memory than CT-/MP+ individuals (p<0.001). No other significant differences were found among the 4 subgroups. No cognitive decline was found at follow-up, neither in the CT+/MP- nor in CT-/MP- group. Lower cognition was not associated with increased symptom severity or poor functioning at follow-up, neither in the CT+/MP- nor in CT-/MP- group. Although cognitive impairments and CT may be related to clinical or functional features of psychotic disorder, and cognitive functioning could be affected by CT exposure, cognition does not discriminate subgroups of patients stratified by CT exposure and MP.

Metacognitive training in patients recovering from a first psychosis: an experience sampling study testing treatment effects.

Cognitive biases, negative affect and negative self-esteem are associated with paranoia in people with psychotic disorders. Metacognitive group training (MCT) aims to target these biases although research has shown mixed results. Our objective was to establish the effect of MCT on paranoid ideation in patients with recent onset psychosis in a powerful experience sampling design. 50 patients between the age of 18 and 35 were included in a single-blind, parallel group RCT comparing MCT with occupational therapy (OT) as an active control condition. We assessed via questionnaires and experience sampling treatment effects on paranoid ideation, delusional conviction, the cognitive bias jumping to conclusion (JTC), and cognitive insight, as well as treatment effects on associations between negative affect, negative self-esteem and paranoid ideation. Patients in the MCT group did not show a decrease in paranoid ideation, delusional conviction, JTC-bias or an increase in cognitive insight compared with OT. However, negative affect showed a weaker association with paranoid ideation post-treatment in the MCT condition. In the OT condition, this association was stronger post-treatment. We tentatively suggest that patients with an early psychosis seemed to benefit from MCT in emotional learning compared with the OT condition. Despite the fact that the group training is well-received by patients, subsequent individual MCT (MCT+) may be indicated for stronger favorable effects on paranoid ideation.

A state-independent network of depressive, negative and positive symptoms in male patients with schizophrenia spectrum disorders.

Depressive symptoms occur frequently in patients with schizophrenia. Several factor analytical studies investigated the associations between positive, negative and depressive symptoms and reported difficulties differentiating between these symptom domains. Here, we argue that a network approach may offer insights into these associations, by exploring interrelations between symptoms. The aims of current study were to I) construct a network of positive, negative and depressive symptoms in male patients with schizophrenia to investigate interactions between individual symptoms; II) identify the most central symptoms within this network and III) examine group-level differences in network connectivity between remitted and non-remitted patients. We computed a network of depressive, positive and negative symptoms in a sample of 470 male patients diagnosed with a psychotic disorder. Depressive symptoms were assessed with the Calgary Depression Rating Scale for Schizophrenia, while psychotic symptoms were assessed with the Positive and Negative Syndrome Scale. Networks of male patients who fulfilled remission criteria (Andreasen et al., 2005) and non-remitters for psychosis were compared. Our results indicate that depressive symptoms are mostly associated with suicidality and may act as moderator between psychotic symptoms and suicidality. In addition, 'depressed mood', 'observed depression', 'poor rapport', 'stereotyped thinking' and 'delusions' were central symptoms within the network. Finally, although remitted male patients had a similar network structure compared to non-remitters the networks differed significantly in terms of global strength. In conclusion, clinical symptoms of schizophrenia were linked in a stable way, independent of symptomatic remission while the number of connections appears to be dependent on remission status.

Obsessive-compulsive symptoms and overall psychopathology in psychotic disorders: longitudinal assessment of patients and siblings.

The course of obsessive-compulsive symptoms (OCS) and its association with alterations in other clinical variables in patients with psychotic disorders is insufficiently known. Patients (n = 602) and unaffected siblings (n = 652) from the Dutch Genetic Risk and Outcome of Psychosis (GROUP) study were investigated at baseline and after 3 years. Participants were assigned to four groups based on the course of OCS over time: no-OCS, persistent OCS, initial OCS and de novo OCS. In addition to cross-sectional comparisons, longitudinal associations between changes in OCS and symptoms of schizophrenia and general functioning were investigated. Patients with co-occurring OCS reported significantly higher severity of psychotic and affective symptoms as well as lower overall functioning compared to patients without OCS. These differences were stable over time for patients reporting persistent OCS. Subsequent repeated measure analysis revealed significant interaction effects for groups reporting changes in their OCS. Whereas the group with remission of initial OCS showed significant improvement in positive symptoms, emotional distress and functioning, the de novo group showed no significant change in these variables, but rather reported stable higher psychopathology. Similar results were found on a subclinical level in siblings. Patients with co-occurring OCS present a more severe clinical picture, especially if symptoms persist over time. The remission of OCS was associated with overall improvement, whereas individuals with de novo OCS already reported higher clinical impairment before OCS onset. More research is needed to elucidate causal pathways and to develop effective interventions for persistent comorbid OCS.

An experience sampling study on the ecological validity of the SWN-20: Indication that subjective well-being is associated with momentary affective states above and beyond psychosis susceptibility.

Subjective well-being (SWB) is associated with treatment adherence and symptom outcome in people with psychotic disorders. Also, it is associated with psychosis susceptibility and it is partly hereditable. The SWN-20 is a widely used tool to assess subjective well-being in patients; it was also found to be suitable for assessing SWB in healthy populations. Yet it is unclear how this retrospectively measured construct may be associated with momentary affective state, which is the proposed underlying mechanism of subjective well-being. This study therefore investigated the ecological validity of the SWN-20 in people at different risk for psychosis. In 63 patients with a psychotic disorder and 61 siblings of patients with a psychotic disorder we assessed whether subjective well-being as measured with the SWN-20, was associated with momentary positive affect, negative affect, reward experience and stress-sensitivity as measured by the experience sample method (ESM). Higher subjective well-being was associated with higher momentary positive affect and lower negative affect, and this association was not conditional on psychosis vulnerability. Subjective well-being was not associated with stress-sensitivity or reward-experience. SWN-20 is an easy-to-use and ecologically valid tool to measure subjective well-being in people with different vulnerability for psychosis.

Dopamine D2-receptor affinity of antipsychotics in relation to subjective well-being in patients with a psychotic disorder.

Dopamine D2-receptor blockade by antipsychotic medication reduces psychotic symptoms, but may reduce subjective well-being. The current study aims to further explore the relation between dopamine D2-receptor affinity and subjective well-being within a large sample of patients with psychotic disorders. Patients participated in a longitudinal naturalistic cohort study: the Genetic Risk and Outcome of Psychosis (GROUP) study. Three groups of antipsychotic medication were created on the basis of their affinity for the D2-receptor: (i) loose or partial agonistic binding, (ii) moderate binding, and (iii) tight binding. Subjective well-being was assessed using the Subjective Well-being under Neuroleptics scale (SWN) at baseline and the 3-year follow-up. In addition, we compared changes in SWN scores when switching to a more 'loose or partial agonistic' binding agent or to a 'tighter' binding agent between baseline and the 3-year follow-up. The final group included 388 patients at baseline and 290 at the 3-year follow-up. No significant differences in the SWN scores were found between the three affinity groups at baseline and the 3-year follow-up. In addition, analyses yielded no significant changes in SWN scores after switching to a more 'loose or partial agonistic' or more 'tight' binding antipsychotic agent. We did not find further support for the hypothesis that subjective well-being is associated with antipsychotics affinity for dopamine D2-receptors. This might imply that the effect of antipsychotic D2-receptors binding on subjective well-being is not large enough to be detected in this cross-sectional study. Other factors besides dopamine antagonism are probably more relevant for subjective well-being.

The associations between childhood trauma, neuroticism and comorbid obsessive-compulsive symptoms in patients with psychotic disorders.

Various studies reported remarkably high prevalence rates of obsessive-compulsive symptoms (OCS) in patients with a psychotic disorder. Little is known about the pathogenesis of this co-occurrence. The current study aimed to investigate the contribution of shared underlying risk factors, such as childhood trauma and neuroticism, to the onset and course of OCS in patients with psychosis. Data were retrieved from 161 patients with psychosis included in the 'Genetic Risk and Outcome in Psychosis' project. Patients completed measures of OCS and psychotic symptoms at study entrance and three years later. Additionally, childhood maltreatment and neuroticism were assessed. Between-group comparisons revealed increased neuroticism and positive symptoms in patients who reported comorbid OCS compared to OCS-free patients. Subsequent mediation analyses suggested a small effect of childhood abuse on comorbid OCS severity at baseline, which was mediated by positive symptom severity. Additionally, results showed a mediating effect of neuroticism as well as a moderating effect of positive symptoms on the course of OCS severity over time. OCS severity in patients with psychosis might thus be associated with common vulnerability factors, such as childhood abuse and neuroticism. Furthermore, the severity of positive symptoms might be associated with more severe or persistent comorbid OCS.

A symptom network structure of the psychosis spectrum.

Current diagnostic systems mainly focus on symptoms needed to classify patients with a specific mental disorder and do not take into account the variation in co-occurring symptoms and the interaction between the symptoms themselves. The innovative network approach aims to further our understanding of mental disorders by focusing on meaningful connections between individual symptoms of a disorder and has thus far proven valuable insights to psychopathology. The aims of current study were to I) construct a symptom network and investigate interactions between a wide array of psychotic symptoms; II) identify the most important symptoms within this network and III) perform an explorative shortest pathway analysis between depressive and delusional symptoms. We analyzed interview data from n=408 male patients with non-affective psychosis using the Comprehensive Assessment of Symptoms and History (CASH). A network structure of 79 symptoms was computed to explore partial correlations between positive, negative, catatonia and affective symptoms. The resulting network showed strong connectivity between individual symptoms of the CASH, both within- and between-domains. Most central symptoms included 'loss of interest', 'chaotic speech', 'inability to enjoy recreational interest in activities', 'inability to form or maintain relationships with friends' and 'poverty of content of speech'. The shortest pathway analysis between depressive and delusional symptoms displayed an important role for 'persecutory delusions'. In conclusion, this study showed that individual psychotic symptoms are meaningfully related to each other not only within their own cluster, but also between different clusters and that important information may be acquired by investigating interactions at a symptom level.

Reduced specialized processing in psychotic disorder: a graph theoretical analysis of cerebral functional connectivity.

BACKGROUND: Previous research has shown that the human brain can be represented as a complex functional network that is characterized by specific topological properties, such as clustering coefficient, characteristic path length, and global/local efficiency. Patients with psychotic disorder may have alterations in these properties with respect to controls, indicating altered efficiency of network organization. This study examined graph theoretical changes in relation to differential genetic risk for the disorder and aimed to identify clinical correlates. METHODS: Anatomical and resting-state MRI brain scans were obtained from 73 patients with psychotic disorder, 83 unaffected siblings, and 72 controls. Topological measures (i.e., clustering coefficient, characteristic path length, and small-worldness) were used as dependent variables in a multilevel random regression analysis to investigate group differences. In addition, associations with (subclinical) psychotic/cognitive symptoms were examined. RESULTS: Patients had a significantly lower clustering coefficient compared to siblings and controls, with no difference between the latter groups. No group differences were observed for characteristic path length and small-worldness. None of the topological properties were associated with (sub)clinical psychotic and cognitive symptoms. CONCLUSIONS: The reduced ability for specialized processing (reflected by a lower clustering coefficient) within highly interconnected brain regions observed in the patient group may indicate state-related network alterations. There was no evidence for an intermediate phenotype and no evidence for psychopathology-related alterations.

The effect of childhood trauma and Five-Factor Model personality traits on exposure to adult life events in patients with psychotic disorders.

INTRODUCTION: Recent life events are associated with transition to and outcome in psychosis. Childhood trauma and personality characteristics play a role in proneness to adult life events. However, little is known about the relative contribution and interrelatedness of these characteristics in psychotic disorders. Therefore, we investigated whether Five-Factor Model (FFM) personality traits and childhood trauma (abuse and neglect) predict adult life events, and whether the effect of childhood trauma on life events is mediated by personality traits. METHOD: One hundred and sixty-three patients with psychotic disorders were assessed at baseline on history of childhood maltreatment and FFM personality traits, and on recent life events at 3-year follow-up. RESULTS: Childhood abuse is associated with negative life events, and part of the effect of childhood abuse on negative life events is mediated by openness to experience. Openness to experience and extraversion are associated with more positive and negative life events. Childhood neglect and lower extraversion are related to experiencing less positive events. CONCLUSION: The association between childhood trauma and recent life events is partly mediated by personality. Future research could focus on mechanisms leading to positive life events, as positive life events may buffer against development of mental health problems.

Grey Matter Changes Associated with Heavy Cannabis Use: A Longitudinal sMRI Study.

Cannabis is the most frequently used illicit drug worldwide. Cross-sectional neuroimaging studies suggest that chronic cannabis exposure and the development of cannabis use disorders may affect brain morphology. However, cross-sectional studies cannot make a conclusive distinction between cause and consequence and longitudinal neuroimaging studies are lacking. In this prospective study we investigate whether continued cannabis use and higher levels of cannabis exposure in young adults are associated with grey matter reductions. Heavy cannabis users (N = 20, age baseline M = 20.5, SD = 2.1) and non-cannabis using healthy controls (N = 22, age baseline M = 21.6, SD = 2.45) underwent a comprehensive psychological assessment and a T1- structural MRI scan at baseline and 3 years follow-up. Grey matter volumes (orbitofrontal cortex, anterior cingulate cortex, insula, striatum, thalamus, amygdala, hippocampus and cerebellum) were estimated using the software package SPM (VBM-8 module). Continued cannabis use did not have an effect on GM volume change at follow-up. Cross-sectional analyses at baseline and follow-up revealed consistent negative correlations between cannabis related problems and cannabis use (in grams) and regional GM volume of the left hippocampus, amygdala and superior temporal gyrus. These results suggests that small GM volumes in the medial temporal lobe are a risk factor for heavy cannabis use or that the effect of cannabis on GM reductions is limited to adolescence with no further damage of continued use after early adulthood. Long-term prospective studies starting in early adolescence are needed to reach final conclusions.

Disturbed Experience of Self: Psychometric Analysis of the Self-Experience Lifetime Frequency Scale (SELF).

BACKGROUND: Schizophrenia is characterized by positive and negative symptoms, but recently anomalous self-experiences, e.g. exaggerated self-consciousness (hyperreflectivity), receive more attention as an important symptom domain in schizophrenia patients. The semi-structured interview, the Examination of Anomalous Self-Experience (EASE) [Psychopathology 2005;38:236-258], examines experiences of a disturbed sense of self in a sophisticated but time-consuming manner. Therefore, we proposed the Self-Experience Lifetime Frequency scale (SELF), an instrument intended to screen for self-disturbance phenomena. Here we compared scores of patients, their siblings and healthy controls on the SELF. Methods and Sampling: The SELF is composed of a validated screener for symptoms of depersonalization complemented by questions covering several other domains of self-disturbance. A total of 426 patients with a psychotic disorder, 526 of their unaffected siblings, and 297 healthy controls completed the SELF. Patients' scores on the 12 items of the SELF were subjected to an explorative principal axis factor analysis (PAF); composite scores on factor components were compared between the three participant groups. RESULTS: The PAF revealed two components, explaining 43.9 and 9.5% of variance, respectively. The first component represents a disturbance of self-awareness; the second component reflects (milder forms of) diminished self-affection or depersonalization. The two components of the SELF revealed good internal consistency (component 1, α = 0.88; component 2, α = 0.79; x03C1; = 0.85). Patients showed significantly higher scores on both factor components in comparison with both siblings and controls. No significant differences were found between siblings and controls. CONCLUSIONS: The findings of the current study suggest that the SELF comprises two components of self-disturbance. Patients reported more (severe) symptoms of self-disturbance on both components, suggesting that it is feasible to screen for self-disturbance phenomena in patients with psychotic disorders with the SELF. Screening for symptoms of self-disturbance is important since these symptoms are associated with suffering and, moreover, these phenomena may mark the transition from intact to aberrant reality testing.

Levels of Red Blood Cell Fatty Acids in Patients With Psychosis, Their Unaffected Siblings, and Healthy Controls.

BACKGROUND: Two recent meta-analyses showed decreased red blood cell (RBC) polyunsaturated fatty acids (FA) in schizophrenia and related disorders. However, both these meta-analyses report considerable heterogeneity, probably related to differences in patient samples between studies. Here, we investigated whether variations in RBC FA are associated with psychosis, and thus may be an intermediate phenotype of the disorder. METHODS: For the present study, a total of 215 patients (87% outpatients), 187 siblings, and 98 controls were investigated for multiple FA analyses. Based on previous studies, we investigated docosahexaenoic acid (DHA), docosapentaenoic acid (DPA), arachidonic acid (AA), linoleic acid (LA), nervonic acid (NA), and eicasopentaenoic acid (EPA). On an exploratory basis, a large number of additional FA were investigated. Multilevel mixed models were used to compare the FA between the 3 groups. RESULTS: Compared to controls, both patients and siblings showed significantly increased DHA, DPA, AA, and NA. LA was significantly higher in siblings compared to controls. EPA was not significantly different between the 3 groups. Also the exploratory FA were increased in patients and siblings. CONCLUSIONS: We found increased RBC FA DHA, DPA, AA, and NA in patients and siblings compared to controls. The direction of change is similar in both patients and siblings, which may suggest a shared environment and/or an intermediate phenotype. Differences between patient samples reflecting stage of disorder, dietary patterns, medication use, and drug abuse are possible modifiers of FA, contributing to the heterogeneity in findings concerning FA in schizophrenia patients.

Association between olfactory identification and parkinsonism in patients with non-affective psychosis.

AIM: Olfactory identification deficits (OIDs) are seen in schizophrenia patients and individuals at increased risk for psychosis but its pathophysiology remains unclear. Although dopaminergic imbalance is known to lie at the core of schizophrenia symptomatology, its role in the development of OIDs has not been elucidated yet. This study investigated the association between OIDs and symptoms of parkinsonism as a derivative of dopaminergic functioning. METHODS: In 320 patients diagnosed with non-affective psychosis, olfactory identification performance was assessed by means of the Sniffin' Sticks task. Level of parkinsonian symptoms was assessed by means of the Unified Parkinson's Disease Rating Scale (UPDRS-III). By means of multiple linear regression with bootstrapping, the association between UPDRS and Sniffin' Sticks score was investigated while correcting for potential confounders. A Bonferroni corrected P-value of 0.007 was used. RESULTS: Higher UPDRS scores significantly predicted worse olfactory identification in patients with non-affective psychosis with an unadjusted b = -0.07 (95% CI -0.10 to -0.04) and an adjusted b = -0.04 (95% CI -0.07 to -0.01). CONCLUSION: Results provide preliminary evidence that the same vulnerability may underlie the development of parkinsonism and OIDs in patients with non-affective psychosis. Further investigation should evaluate the clinical value of OIDs as a marker of dopaminergic vulnerability that may predict psychosis.

Structural MRI Differences between Patients with and without First Rank Symptoms: A Delusion?

OBJECTIVE: It has been suggested that specific psychotic symptom clusters may be explained by patterns of biological abnormalities. The presence of first rank symptoms (FRS) has been associated with cognitive abnormalities, e.g., deficits in self-monitoring or in the experience of agency, suggesting that a specific network of neural abnormalities might underlie FRS. Here, we investigate differences in cortical and subcortical brain volume between patients with and without FRS. METHODS: Three independent patient samples (referred to as A, B, and C) with different mean ages and in different illness stages were included, leading to a total of 348 patients within the schizophrenia-spectrum. All underwent magnetic resonance imaging of the brain. In addition, the presence of FRS was established using a diagnostic interview. Patients with (FRS+, A: n = 63, B: n = 129, and C: n = 96) and without FRS (FRS-, A: n = 35, B: n = 17, and C: n = 8) were compared on global and local cortical volumes as well as subcortical volumes, using a whole brain (cerebrum) approach. RESULTS: Nucleus accumbens volume was significantly smaller in FRS+ as compared with FRS- in sample A (p < 0.005). Furthermore, FRS+ showed a smaller volume of the pars-opercularis relative to FRS- in sample B (p < 0.001). No further significant differences were found in cortical and subcortical volumes between FRS+ and FRS- in either one of the three samples after correction for multiple comparison. CONCLUSION: Brain volume differences between patients with and without FRS are, when present, subtle, and not consistent between three independent samples. Brain abnormalities related to FRS may be too subtle to become visible through structural brain imaging.