example, we have recently found that a particular EEG connectivity method can reveal resting-state fMRI-like network structure (3), distinguish response to an antidepressant medication and placebo when assessed prior to treatment (4), and provide rich data to support robust individual-level treatment prediction through machine learning (5).Indeed, given the use of radioactivity and the higher cost (relative to EEG) of positron emission tomography or single-photon emission computed tomography, as advocated for by Henderson et al., EEG may ultimately prove to be the ideal tool for real-world applications.Nonetheless, unless the way we ask and answer questions using any form of neuroimaging changes, it is my position that little is likely to change in terms of either mechanistic insight or creation of diagnostics ready for clinical care.

We tested for effects of dopamine function (as measured with PET) on hippocampal activity and hippocampal-parietal coupling, previously shown to be a reliable intermediate phenotype for schizophrenia, i.e. abnormal in patients with schizophrenia and their healthy siblings (Rasetti et al, 2013). Based on prior evidence of dopamine dysfunction in schizophrenia, we hypothesized that this intermediate phenotype would be modulated by dopamine tone.

Background: Dopamine (DA) dysfunction is involved in deficits underlying working memory (WM) and prefrontal cortical (PFC) physiology in patients with schizophrenia. Evidence indicates that DA stabilizes and focuses the prefrontal cortical web by modulating NMDA, non-NMDA, and GABAergic networks. Catechol-O-methyl transferase (COMT) plays a role in regulating dopamine release in the PFC. Val[158]Met, a common COMT functional polymorphism, affects PFC function and WM capacity and has been associated with cognitive deficits in schizophrenia. Tolcapone, a COMT inhibitor that minimally penetrates the blood–brain barrier, has been shown to improve executive function and PFC efficiency as observed in BOLD fMRI studies in normal volunteers. We also previously found that tolcapone’s effect on neuropsychological tasks was modulated by COMT val-met genotype. Methods: In the current study, we sought to determine whether tolcapone (100 mg three times a day on the first day and 200 mg 3 times a day for the next 6 days) or placebo would have an effect on PFC recruitment of neuronal resources in patients with schizophrenia. We randomized 33 subjects following a within-subjects, counterbalanced study design and enrolled them to participate in a double-blinded, cross-over, placebo-controlled trial. Subjects underwent BOLD fMRI on the seventh day of each arm while performing the N-Back working memory task (1-Back, 2-Back, and 3-Back). Comparing the three COMT genotypes, the 33 subjects (6 women) are not different in age, gender, IQ or race. We performed a 3-way ANCOVA on percentage accuracy with Drug, Load, and Genotype as factors in SAS 9.3. Results: There was a significant main effect of drug (tolcapone > placebo, P = .0034) and load (P < .0001) on N-Back performance test. We processed the fMRI data in SPM12 and obtained the placebo-tolcapone contrast map for each participant with first level analysis. These first-level contrast maps were entered into group analysis using a 2-way ANCOVA with load and genotype as factors and accuracy as a covariate of no interest. In parallel to the performance results, there were significant effects of drug in WM load on prefrontal BOLD signal change. Although all genotypes showed decreased bilateral DLPFC activation on tolcapone compared to the placebo condition, post-hoc analysis showed that Val/Val homozygotes had the strongest reduction (P = .045) in the right DLPFC compared to the other two genotype groups when the signal was extracted from the placebo > tolcapone contrast with all genotypes and all load effects combined. Conclusion: Our results are consistent with previous findings in healthy volunteers of tolcapone’s COMT inhibitory effect improving information processing, especially in Val/Val homozygotes. These findings suggest that in patients with schizophrenia also, tolcapone improves PFC efficiency during working memory and its effect is most likely modulated by COMT Val-Met genotype.

A data-driven hypothesis-free genome-wide association (GWA) approach in imaging genetics studies allows screening the entire genome to discover novel genes that modulate brain structure, chemistry, and function. However, a whole brain voxel-wise analysis approach in such genome-wide based imaging genetic studies can be computationally intense and also likely has low statistical power since a stringent multiple comparisons correction is needed for searching over the entire genome and brain. In imaging genetics with functional magnetic resonance imaging (fMRI) phenotypes, since many experimental paradigms activate focal regions that can be pre-specified based on a priori knowledge, reducing the voxel-wise search to single-value summary measures within a priori ROIs could prove efficient and promising. The goal of this investigation is to evaluate the sensitivity and reliability of different single-value ROI summary measures and provide guidance in future work. Four different fMRI databases were tested and comparisons across different groups (patients with schizophrenia, their siblings, vs. normal control subjects; across genotype groups) were conducted. Our results show that four of these measures, particularly those that represent values from the top most-activated voxels within an ROI are more powerful at reliably detecting group differences and generating greater effect sizes than the others.

The neuregulin 3 gene (NRG3) plays pleiotropic roles in neurodevelopment and is a putative susceptibility locus for schizophrenia. Specifically, the T allele ofNRG3rs10748842 has been associated with illness risk, altered cognitive function, and the expression of a novel splice isoform in prefrontal cortex (PFC), but the neural system effects are unexplored. Here, we report an association between rs10748842 and PFC physiology as measured by functional magnetic resonance imaging of human working memory performance, where a convincing link between increased genetic risk for schizophrenia and increased activation in some PFC areas has been established. In 410 control individuals (195 males, 215 females), we detected a highly significant effect ofNRG3genotype manifesting as an unanticipated increase in ventrolateral PFC activation in nonrisk-associated C allele carriers. An additional analysis including 78 patients with schizophrenia spectrum disorders (64 males, 14 females) and 123 unaffected siblings (53 males, 70 females) revealed a whole-brain significant genotype by group interaction in right dorsolateral PFC (DLPFC), manifesting as a relative activation increase in healthy controls and siblings (C > T/T) and as a hypoactivation in patients (T/T > C). These observed genotype-dependent effects in PFC were not explained by task performance and did not conform to established locales of prefrontal inefficiency linked to genetic risk for schizophrenia. Our data indicate a complex modulation of brain physiology by rs10748842, which does not fit the simple inefficiency model of risk association in DLPFC and suggests that other neurobiological mechanisms are involved.

IMPORTANCE:Declarative memory-the ability to learn, store, and retrieve information-has been consistently reported to be altered in schizophrenia, and hippocampal-parahippocampal dysfunction has been implicated in this deficit. To elucidate the possible role of genetic risk factors in such findings, it is necessary to study healthy relatives of patients with schizophrenia who carry risk-associated genes but not the confounding factors related to the disorder.OBJECTIVE:To investigate whether altered brain responses, particularly in the hippocampus and parahippocampus, during the encoding phase of a simple declarative memory task are also observed in unaffected siblings who are at increased genetic risk for schizophrenia.DESIGN, SETTING, AND PARTICIPANTS:Functional magnetic resonance imaging was used with a simple visual declarative memory paradigm to test for differences in neural activation across normal control participants, patients with schizophrenia, and their healthy siblings. This study was conducted at a research center and included a total of 308 participants (181 normal control participants, 65 healthy siblings, and 62 patients with schizophrenia); all participants were white of European ancestry.MAIN OUTCOMES AND MEASURES:All participants completed a declarative memory task involving incidental encoding of neutral visual scenes interleaved with crosshair fixation while undergoing functional magnetic resonance imaging. Differences in hippocampus and parahippocampus activation and coupling across groups and correlations with accuracy were analyzed. Analyses were repeated in pairwise-matched samples.RESULTS:Both patients with schizophrenia and their healthy siblings showed reduced parahippocampal activation (bilaterally) and hippocampal-parietal (BA 40) coupling during the encoding of novel stimuli when compared with normal control participants. There was a significant positive correlation between parahippocampal activation during encoding and the visual-memory score.CONCLUSIONS AND RELEVANCE:These results suggest that altered hippocampal-parahippocampal function during encoding is an intermediate biologic phenotype related to increased genetic risk for schizophrenia. Therefore, measuring hippocampal-parahippocampal function with neuroimaging represents a potentially useful approach to understanding genetic mechanisms that confer risk for schizophrenia.

Background Attention is the capacity to flexibly orient behaviors and thoughts towards a goal by selecting and integrating relevant contextual information. The dorsal cingulate (dCC) and prefrontal (PFC) cortices play critical roles in attention. Evidence indicates that catechol- O -methyltransferase (COMT) modulates dopaminergic tone in the PFC and dCC. Objective In this study, we explored the effect of tolcapone, a CNS penetrant COMT inhibitor that increases cortical dopamine levels, on brain activity during a Variable Attentional Control (VAC) task. Study Design We performed a double-blinded, placebo-controlled, counter-balanced trial with tolcapone (Tasmar, tablets, 100 mg three times a day for 1 day and then 200 mg three times a day for 6 days; ClinicalTrials.gov identifier: NCT00044083). Setting The study was conducted in the Clinical Center of the National Institute of Mental Health from 2005 to 2009. Patients Twenty healthy volunteers (11 males; mean age = 32.7 years) with good imaging and performance data on both arms of the study were investigated. Intervention Participants underwent 3T blood-oxygen-level-dependent (BOLD) functional magnetic resonance imaging (fMRI) while performing the event-related VAC task, which varies attention over three levels of load: LOW, INT (intermediate), and HIGH. Main Outcome Measure Changes in behavioral data and individual contrast images were analyzed using ANOVA with drug and task load as co-factors. Results There was a significant main effect of increasing task load, with resulting decreased accuracy and increased reaction time. While there was no significant effect of tolcapone on these behavioral measures, the neuroimaging data showed a significant effect on load-related changes in dCC, with significantly lower dCC activation on tolcapone compared with placebo. Further, neural activity in dCC correlated positively with COMT enzyme activity (i.e., lower COMT activity and presumably more dopamine was associated with lower activation in dCC, i.e., more efficient information processing). Conclusion Our results show that pharmacological reduction of COMT activity modulates the engagement of attentional mechanisms, selectively enhancing the efficiency of dCC processing in healthy volunteers, reflected as decreased activity for the same level of performance.

Schizophrenia has heritability estimates of 70–85%1 and genetic risk in most cases is presumably a result of multiple genetic loci of small effect. In recent years, genome-wide association studies have facilitated the discovery of potential risk genes for neuropsychiatric disorders. ZNF804A rs1344706 was the first single-nucleotide polymorphism (A/C, A = risk allele) to show a significant association with schizophrenia in genome-wide association studies (P = 1.6 × 10–7).2 Although the physiological function of ZNF804A and its role in schizophrenia risk is currently unclear, the gene has been shown to be associated with psychosis,3 and several potential intermediate biological phenotypes, such as deficits in executive function4 and altered cortical connectivity during working memory5,6 and theory of mind.7 Cognitive deficits in schizophrenia are broad and conspicuously include deficits in cognitive control, an executive function that refers to the ability to direct behavior toward a goal in the presence of conflict. Studies have shown altered function and connectivity of the dorsolateral prefrontal cortex (DLPFC) and anterior cingulate cortex (ACC) in patients with schizophrenia during cognitive control tasks.8 Recently, these alterations have been suggested to represent an intermediate phenotype because they are also found in healthy siblings of patients with schizophrenia.9,10 In this study, we aimed to explore the role of ZNF804A rs1344706 on activation and functional connectivity measures related to cognitive control. To this end, we used the Modified Flanker task that includes response inhibition (RI) and interference monitoring and suppression (IMS), two important components of cognitive control function. A total of 208 Caucasian healthy volunteers with no history of psychosis and no first-degree relatives with a schizophrenia spectrum disorder and with good quality functional magnetic resonance imaging (fMRI) data and genotype information for ZNF804A rs1344706 were selected from the larger sample of the Clinical Brain Disorders Branch Sibling Study of schizophrenia at the National Institute of Mental Health (DR Weinberger PI). In all, 89 subjects were rs1344706 AA homozygotes, 93 were rs1344706 AC heterozygotes and 26 were rs1344706 CC homozygotes. The genotype groups did not differ across demographic and task performance variables based on ANOVA and chi-square analyses (see Supplementary Materials, Supplementary Table 1). Subjects underwent BOLD fMRI using a gradient echo-planar imaging sequence on a 3T GE Signa scanner during which they performed a modified Flanker Task. fMRI data was processed using SPM5 (SPM; http://www.fil.ion.ucl.ac.uk). Genotype effects on cognitive control-dependent neural response and connectivity were tested using random-effects general linear model ANOVA analysis (P<0.05; small volume corrected Pfdr<0.05) (see Supplementary Materials). To examine the cognitive control-dependent modulation of functional coupling of ACC and DLPFC, a psychophysiological interaction (PPI) analysis was performed using both ACC and right DLPFC as seed regions. The choice of ACC (identified through WFU-pickatlas toolbox; http://fmri.wfubmc.edu/software/PickAtlas) as one of the seed regions was based on an earlier observation of altered ACC/DLPFC coupling during cognitive control representing a potential intermediate phenotype.9 The choice of the second seed region in the right DLPFC (right Brodmann areas 9 and 46) was based on results from previous studies,5,6 which showed that the coupling of this brain region with other brain regions is modulated by ZNF804A rs1344706 during cognitive processing (see Supplementary Materials). During RI, although there was no significant difference in activation across genotype groups, PPI analysis revealed increased connectivity between the ACC and right DLPFC in A, risk allele, homozygotes as well as heterozygotes when compared with C homozygotes. This was observed irrespective of the seed region, the right DLPFC (x, y, z = 6, 27, 21, Z = 3.73, Pfdr = 0.037, see Figure 1a) or ACC, although the latter did not survive correction for multiple comparisons (P = 0.006 uncorrected). There were no other areas that showed a significant effect of genotype on functional coupling with the seed regions during RI. During IMS, A, risk allele, homozygotes as well as heterozygotes showed decreased right DLPFC and ACC activation when compared with C homozygotes (DLPFC: x, y, z = 51, 39, 15, Z = 4.00, Pfdr = 0.011; ACC: x, y, z = 3, 30, 27, Z = 2.79, Pfdr = 0.026; see Figure 1b). PPI revealed no significant difference in connectivity across genotype groups during IMS. Figure 1 Effect of ZNF804A rs1344706 genotype on cognitive-control-related neural function during RI and IMS conditions of the Modified Flanker task. (a) During RI, PPI analysis revealed increased rDLPFC connectivity with the ACC (Pfdr = 0.037) in A, risk allele, ... Our results show that ZNF804A modulates mechanisms underlying cognitive control. The ZNF804A rs1344706 allele load effect on ACC-PFC coupling, with risk allele carriers showing increased coupling, adds to evidence that ZNF804A modulates cortical network connectivity during executive cognition.5 We have previously found that this pattern of enhanced ACC-PFC functional coupling is associated with schizophrenia and with increased genetic risk for schizophrenia,9 suggesting that it is an intermediate biological phenotype related to the genetic risk architecture of illness. This adds to evidence that ZNF804a may confer risk for schizophrenia by impacting this intermediate phenotype mechanism. Interestingly, we also found that ZNF804A modulates ACC and DLPFC activation during IMS. Although a similar alteration in ACC and DLPFC activation during IMS was observed in patients with SCZ,9 it has not been shown to be an intermediate phenotype related to risk for schizophrenia. Therefore, further studies may be necessary to clarify if this effect of ZNF804A on ACC and DLPFC activation during IMS is independent of the mechanism through which it confers genetic risk for schizophrenia.

Aberrant activity in brain regions underlying various aspects of executive cognition has been reported in patients with schizophrenia and in their healthy relatives, suggesting an association with genetic liability. The aim of this study was to investigate brain responses to selective aspects of cognitive control in unaffected siblings who are at increased genetic risk of schizophrenia. Altogether, 65 non-affected siblings, 70 patients with schizophrenia spectrum disorders, and 235 normal controls participated in this study. Blood-oxygen-Ievel-dependent functional magnetic resonance imaging was conducted while participants performed a cognitive control task (‘flanker task’) to identify brain activity and connectivity associated with response inhibition and conflict monitoring, and suppression. Behaviorally, similar to patients with schizophrenia, siblings were less accurate when inhibiting prepotent responses relative to normal controls. During response inhibition, again similar to patients with schizophrenia, siblings showed decreased activity in the anterior cingulate (ACC), along with increased functional coupling with the dorsolateral prefrontal cortex (PFC) when compared to normal controls. Our findings show altered ACC activity and PFC connectivity in unaffected siblings and patients with schizophrenia during response inhibition. These results suggest that such changes in the neural activity underlying aspects of cognitive control may represent a potential intermediate phenotype for the investigation of the genetic basis of schizophrenia.

Context: Studies have shown patterns of abnormal dorsolateral prefrontal cortex (DLPFC) functional connectivity with other brain areas in schizophrenia and association of these patterns with a putative susceptibility gene (ZNF804A). However, whether these patterns are trait phenomena linked to genetic risk for illness is unclear.Objective: To test the hypotheses that altered DLPFC connectivity is (1) a familial, likely heritable feature of genetic risk for schizophrenia, (2) a novel intermediate phenotype independent of altered DLPFC engagement, and (3) selectively modulated by a polymorphism in ZNF804A.Design: Cross-sectional case-control study using blood oxygen level-dependent functional magnetic resonance imaging during a working memory task and genotyping of rs1344706 in ZNF804A.Setting: Research center.Participants: A total of 402 subjects (153 cognitively normal controls, 171 healthy siblings of patients with schizophrenia, and 78 patients).Main Outcome Measures: Task-independent and task-dependent physiologic coupling between the DLPFC and other brain "target" regions investigated with (1) seeded connectivity and (2) psychophysiological interaction analysis.Results: Siblings and patients showed greater DLPFC" in-efficiency" than controls. Abnormal DLPFC functional coupling with the hippocampus and, to a lesser degree, the rest of the prefrontal cortex, was observed in patients and siblings when compared with controls using both connectivity analyses. Prefrontal activation and connectivity measures within siblings did not correlate, implying that they were independent phenomena. The ZNF804A genotype significantly modulated DLPFC coupling with the hippocampus and prefrontal cortex but not DLPF Cactivity in the control group. Similarly, ZNF804A genotype modulated right DLPFC-hippocampal formation coupling in siblings and patients.Conclusions: Coupling between the DLPFC and hippocampus is compromised in siblings of patients with schizophrenia and is independent of DLPFC engagement. The selective association with a single-nucleotide polymorphism in ZNF804A suggests that this intermediate phenotype proxies a distinct neural system mechanism related to genetic risk for schizophrenia and the biology of this gene.

The small effect size of most individual risk factors for psychiatric disorders likely reflects biological heterogeneity and diagnostic imprecision, which has encouraged genetic studies of intermediate biological phenotypes that are closer to the molecular effects of risk genes than are the clinical symptoms. Neuroimaging-based intermediate phenotypes have emerged as particularly promising because they map risk associated gene effects onto physiological processes in brain that are altered in patients and in their healthy relatives. Recent evidence using this approach has elucidated discrete, dissociable biological mechanisms of risk genes at the level of neural circuitries, and their related cognitive functions. This approach may greatly contribute to our understanding of the genetics and pathophysiology of psychiatric disorders.

Modafinil differs from other arousal-enhancing agents in chemical structure, neurochemical profile, and behavioral effects. Most functional neuroimaging studies to date examined the effect of modafinil only on information processing underlying executive cognition, but cognitive enhancers in general have been shown to have pronounced effects on emotional behavior, too. We examined the effect of modafinil on neural circuits underlying affective processing and cognitive functions. Healthy volunteers were enrolled in this double-blinded placebo-controlled trial (100 mg/day for 7 days). They underwent BOLD fMRI while performing an emotion information-processing task that activates the amygdala and two prefrontally dependent cognitive tasks-a working memory (WM) task and a variable attentional control (VAC) task. A clinical assessment that included measurement of blood pressure, heart rate, the Hamilton anxiety scale, and the profile of mood state (POMS) questionnaire was also performed on each test day. BOLD fMRI revealed significantly decreased amygdala reactivity to fearful stimuli on modafinil compared with the placebo condition. During executive cognition tasks, a WM task and a VAC task, modafinil reduced BOLD signal in the prefrontal cortex and anterior cingulate. Although not statistically significant, there were trends for reduced anxiety, for decreased fatigue-inertia and increased vigor-activity, as well as decreased anger-hostility on modafinil. Modafinil in low doses has a unique physiologic profile compared with stimulant drugs: it enhances the efficiency of prefrontal cortical cognitive information processing, while dampening reactivity to threatening stimuli in the amygdala, a brain region implicated in anxiety.

Objective: Over the past few decades it has been emphasized the importance of social functioning and quality of life as a part of a multidimensional assessment of outcome in the evaluation of the impact of psychosis on patients' daily lives. Their relation with schizophrenia symptoms has widely been studied, showing contrasting results.. Little is known concerning their relationship with subjective experiences in schizophrenia.Method: One hundred and eighteen consecutive outpatients affected by schizophrenia in stable phase of illness were recruited for the study. Clinical scales were used to assess objective (Positive and Negative Syndrome Scale: PANSS, Calgary Depression Scale for Schizophrenia: CDSS) and subjective symptoms (Questionario dci SintomiBase: FBF), global functioning and quality of life (Global Assessment of Functioning: GAF, Quality Of Life scale: QLS).Results: After iterative stepwise entries, the combination of three predictor variables (PANSS-positive symptoms subscale, PANSS-negative symptoms subscale, FBF) provided the best-fit GAF model for the data. The combination of two predictor variables (PANSS-negative symptoms subscale, FBF) provided the best-fit QLS- Intrapsychic Foundations subscale model for the data.Conclusions: Our study contributes to underline the necessity to include subjective experiences among the clinical features of schizophrenic patients that must be object of attention. Even if unrelated with objective symptoms assessed by PANSS, they showed a significant correlation with functional outcome and quality of life.