REM Sleep Measures and REM Vagal Activity Predict Extinction Recall in Trauma-Exposed Individuals.

Accumulating evidence suggests that rapid eye movement sleep (REM) supports the consolidation of extinction memory. REM is disrupted in PTSD, and REM abnormalities after traumatic events increase the risk of developing PTSD. Therefore, it was hypothesized that abnormal REM in trauma-exposed individuals may pave the way for PTSD by interfering with the processing of extinction memory. In addition, PTSD patients display reduced vagal activity. Vagal activity contributes to the strengthening of memories, including fear extinction memory, and recent studies show that the role of vagus in memory processing extends to memory consolidation during sleep. Therefore, it is plausible that reduced vagal activity during sleep in trauma-exposed individuals may be an additional mechanism that impairs extinction memory consolidation. However, to date, the contribution of sleep vagal activity to the consolidation of extinction memory or any emotional memory has not been investigated. To test these hypotheses, we examined the association of extinction memory with REM characteristics and REM vagal activity (indexed as high-frequency heart rate variability; HF-HRV) in a large sample of trauma-exposed individuals (n=113). Consistent with our hypotheses, REM sleep characteristics (increased REM density and shortened REM latency) were associated with poorer physiological and explicit extinction memory. Furthermore, higher HF-HRV during REM was associated with better explicit extinction memory. These findings support the notion that disrupted REM may contribute to PTSD by impairing the consolidation of extinction memory and indicate the potential utility of interventions that target REM sleep characteristics and REM vagal activity in fear-related disorders.

Emotional memories are enhanced when reactivated in slow wave sleep, but impaired when reactivated in REM.

Sleep supports memory consolidation. However, it is not completely clear how different sleep stages contribute to this process. While rapid eye movement sleep (REM) has traditionally been implicated in the processing of emotionally charged material, recent studies indicate a role for slow wave sleep (SWS) in strengthening emotional memories. Here, to directly examine which sleep stage is primarily involved in emotional memory consolidation, we used targeted memory reactivation (TMR) in REM and SWS during a daytime nap. Contrary to our hypothesis, reactivation of emotional stimuli during REM led to impaired memory. Consistent with this, REM% was correlated with worse recall in the group that took a nap without TMR. Meanwhile, cueing benefit in SWS was strongly correlated with the product of times spent in REM and SWS (SWS-REM product), and reactivation significantly enhanced memory in those with high SWS-REM product. Surprisingly, SWS-REM product was associated with better memory for reactivated items and poorer memory for non-reactivated items, suggesting that sleep both preserved and eliminated emotional memories, depending on whether they were reactivated. Notably, the emotional valence of cued items modulated both sleep spindles and delta/theta power. Finally, we found that emotional memories benefited from TMR more than did neutral ones. Our results suggest that emotional memories decay during REM, unless they are reactivated during prior SWS. Furthermore, we show that active forgetting complements memory consolidation, and both take place across SWS and REM. In addition, our findings expand upon recent evidence indicating a link between sleep spindles and emotional processing.

Abnormal Brain Bioenergetics in First-Episode Psychosis.

BACKGROUND: Converging evidence indicates impaired brain energy metabolism in schizophrenia and other psychotic disorders. Creatine kinase (CK) is pivotal in providing adenosine triphosphate in the cell and maintaining its levels when energy demand is increased. However, the activity of CK has not been investigated in patients with first-episode schizophrenia spectrum disorders. METHODS: Using in vivo phosphorus magnetization transfer spectroscopy, we measured CK first-order forward rate constant (k f ) in the frontal lobe, in patients with first-episode psychosis (FEP; n = 16) and healthy controls (n = 34), at rest. RESULTS: CK k f was significantly reduced in FEP compared to healthy controls. There were no differences in other energy metabolism-related measures, including phosphocreatine (PCr) or ATP, between groups. We also found increase in glycerol-3-phosphorylcholine, a putative membrane breakdown product, in patients. CONCLUSIONS: The results of this study indicate that brain bioenergetic abnormalities are already present early in the course of schizophrenia spectrum disorders. Future research is needed to identify the relationship of reduced CK k f with psychotic symptoms and to test treatment alternatives targeting this pathway. Increased glycerol-3-phosphorylcholine is consistent with earlier studies in medication-naïve patients and later studies in first-episode schizophrenia, and suggest enhanced synaptic pruning.

Bioenergetics and abnormal functional connectivity in psychotic disorders.

Psychotic Disorders such as schizophrenia (SZ) and bipolar disorder (BD) are characterized by abnormal functional connectivity (FC) within neural networks such as the default mode network (DMN), as well as attenuated anticorrelation between DMN and task-positive networks (TPN). Bioenergetic processes are critical for synaptic connectivity and are also abnormal in psychotic disorders. We therefore examined the association between brain energy metabolism and FC in psychotic disorders. 31P magnetization transfer spectroscopy from medial prefrontal cortex (MPFC) and whole-brain fMRI data were collected from demographically matched groups of SZ, BD, and healthy control (HC) subjects. The creatine kinase (CK) reaction flux calculated from spectroscopy was used as an index of regional energy production rate. FC maps were generated with MPFC as the seed region. Compared to HC, SZ showed significantly lower CK flux, while both BD and SZ patients showed decreased anticorrelation between MPFC and TPN. CK flux was significantly correlated with FC between MPFC and other DMN nodes in HC. This positive correlation was reduced modestly in BD and strongly in SZ. CK flux was negatively correlated with the anticorrelation between MPFC and TPN in HC, but this relationship was not observed in BD or SZ. These results indicate that MPFC energy metabolism rates are associated with stronger FC within networks and stronger anticorrelation between networks in HC. However, this association is decreased in SZ and BD, where bioenergetic and FC abnormalities are evident. This pattern may suggest that impairment in energy production in psychotic disorders underlies the impaired neural connectivity.

Brain lactate and pH in schizophrenia and bipolar disorder: a systematic review of findings from magnetic resonance studies.

Converging evidence from molecular to neuroimaging studies suggests brain energy metabolism abnormalities in both schizophrenia and bipolar disorder. One emerging hypothesis is: decreased oxidative phosphorylation leading to accumulation of lactic acid from glycolysis and subsequent acidification of tissue. In this regard, integrating lactate and pH data from magnetic resonance spectroscopy (MRS) studies in both diseases may help us understand underlying neurobiological mechanisms. In order to achieve this goal, we performed a systematic search of case-control studies examining brain lactate or pH among schizophrenia and/or bipolar patients by using MRS. Medline/Pubmed and EBSCO databases were searched separately for both diseases and outcomes. Our search yielded 33 studies in total composed of 7 lactate and 26 pH studies. In bipolar disorder, 5 out of 6 studies have found elevated lactate levels especially in the cingulate cortex and 4 out of 13 studies reported reduced pH in the frontal lobe. In contrast, in schizophrenia a single study has examined lactate and reported elevation, while only 2 out of 13 studies examining pH have reported reduction in this measure. There were no consistent patterns for the relationship between lactate or pH levels and medication use, disease type, mood state, and other clinical variables. We highlight the need for future studies combining 1H-MRS and 31P-MRS approaches, using longitudinal designs to examine lactate and pH in disease progression across both schizophrenia and bipolar disorders.

Demographic and clinical characteristics associated with a history of bizarre delusions in a cross-diagnostic sample of individuals with psychotic disorders.

Bizarre delusions (BizD) are not specific to schizophrenia (SZ) and can be found in other psychotic disorders. However, to date, there are no studies investigating socio-demographic and clinical characteristics associated with BizD across the psychosis spectrum. In this study 819 subjects with a diagnosis of SZ (n = 250), schizoaffective disorder (SZA) (n = 228) and bipolar I disorder (BD) (n = 341) were included. Patients with history of BizD and with no BizD were compared with respect to socidemographic and clinical variables, and predictors of BizD were explored. Patients with BizD were less educated, less likely to be married, had higher Positive and Negative Syndrome Scale (PANSS) negative scores and lower Young Mania Rating Scale scores. Younger age, SZ and SZA diagnoses, higher PANSS positive scores, presence of reference delusions, tactile and olfactory hallucinations were predictors. Our results indicate that BizD are associated with higher illness severity, lower functionality and specific set of symptoms.

Abnormalities in High-Energy Phosphate Metabolism in First-Episode Bipolar Disorder Measured Using 31P-Magnetic Resonance Spectroscopy.

BACKGROUND: Brain energy metabolism is critical for supporting synaptic function and information processing. A growing body of evidence suggests abnormalities in brain bioenergetics in psychiatric disorders, including both bipolar disorder (BD) and schizophrenia. 31P magnetic resonance spectroscopy provides a noninvasive window into these processes in vivo. Using this approach, we previously showed that patients with BD show normal adenosine triphosphate (ATP) and phosphocreatine levels at rest but cannot maintain normal ATP levels in the visual cortex during times of high energy demand (photic stimulation). Because ATP is replenished from phosphocreatine via the creatine kinase reaction, we have now measured the creatine kinase forward reaction rate constant in BD. METHODS: We studied 20 patients experiencing a first episode of BD and 28 healthy control participants at 4T and quantified creatine kinase forward reaction rate constant using 31P magnetization transfer magnetic resonance spectroscopy as described previously. RESULTS: We found a significant reduction in creatine kinase forward reaction rate constant in the BD group (F = 4.692, p = .036), whereas brain ATP and phosphocreatine concentrations, as well as brain parenchymal pH, were normal. CONCLUSIONS: These results pinpoint a specific molecular mechanism underlying our previous observation of an inability to replenish brain ATP during times of high energy demand in BD.

Brain bioenergetics and redox state measured by 31P magnetic resonance spectroscopy in unaffected siblings of patients with psychotic disorders.

BACKGROUND: Brain bioenergetic anomalies and redox dysregulation have been implicated in the pathophysiology of psychotic disorders. The present study examined brain energy-related metabolites and the balance between nicotinamide adenine dinucleotide metabolites (oxidized NAD+ and reduced NADH) using 31P-magnetic resonance spectroscopy (31P-MRS) in unaffected siblings, compared to first episode psychosis (FEP) patients and healthy controls. METHODS: 21 unaffected siblings, 32 FEP patients (including schizophrenia spectrum and affective psychoses), and 21 controls underwent 31P-MRS in the frontal lobe (6×6×4cm3) on a 4T MR scanner, using custom-designed dual-tuned surface coil with outer volume suppression. Brain parenchymal pH and steady-state metabolite ratios of high energy phosphate compounds were measured. NAD+ and NADH levels were determined using a 31P-MRS fitting algorithm. 13 unaffected sibling-patient pairs were related; other patients and siblings were unrelated. ANCOVA analyses were used to examine 31P-MRS measures, with age and gender as covariates. RESULTS: The phosphocreatine/adenosine triphosphate ratio was significantly reduced in both unaffected siblings and FEP patients, compared to controls. NAD+/NADH ratio was significantly reduced in patients compared to siblings and controls, with siblings showing a reduction in NAD+/NADH compared to controls that was not statistically significant. Compared to patients and controls, siblings showed significantly reduced levels of NAD+. Siblings did not differ from patients or controls on brain pH. DISCUSSION: Our results indicate that unaffected siblings show some, but not all the same abnormalities in brain energy metabolites and redox state as FEP patients. Thus, 31P-MRS studies may identify factors related both to risk and expression of psychosis.

McLean OnTrack: a transdiagnostic program for early intervention in first-episode psychosis.

AIMS: Most programs specializing in the treatment of first-episode psychosis in the United States focus on schizophrenia. However, many early psychosis patients do not fit into this diagnostic category. Here we describe McLean OnTrack, an intensive outpatient treatment program that accepts all comers with first-episode psychosis. METHODS: We assessed baseline characteristics of patients in the 2.5 years since program initiation. We examined how initial referral diagnoses compare with current diagnoses, calculating the proportion of diagnostic changes. RESULTS: At 2.5 years, patients in McLean OnTrack consist of 30 (33.0%) individuals with primary psychotic disorder, 40 (44.0%) with affective psychosis, 19 (20.9%) with psychotic disorder not otherwise specified (NOS) who do not meet full criteria for either category and two (2.2%) individuals with no psychosis. Although patients with affective psychosis had higher pre-morbid functioning, all three categories of psychosis had similar rates of prior hospitalizations and substance use. The retention rate in the psychotic disorder NOS group was lower than that in affective and primary psychotic disorders. Finally, diagnoses changed over the course of treatment in 50.5% of patients. CONCLUSIONS: Diagnostic heterogeneity appears to be the norm among patients with first-episode psychosis, and diagnoses commonly evolve over the illness course. Baseline indices of illness severity were similar across categories and suggest the need for early intervention, irrespective of specific diagnosis. We discuss the benefits and challenges of a transdiagnostic approach to early intervention in first-episode psychosis, treating patients who share many but not all characteristics.

Proton Magnetic Resonance Spectroscopy in Social Anxiety Disorder.

In the present study, 24 nonmedicated patients with social anxiety disorder (SAD) were compared with 24 healthy control subjects to assess metabolite levels in the anterior cingulate, insula, caudate, and putamen using proton magnetic resonance spectroscopy. The ratio of N-acetylaspartate (NAA)/creatine (Cr) was significantly higher in patients with SAD than in healthy control subjects in the anterior cingulate and insula. NAA/Cr ratios in the insula correlated positively with the Liebowitz Social Anxiety Scale total scores in patients with SAD. Our results support the significance and biochemical involvement of the anterior cingulate and insula in the pathophysiology of SAD.

Gray matter abnormalities in patients with social anxiety disorder: A voxel-based morphometry study.

The main objective of this study was to investigate the gray matter volume (GMV) differences between the patients with social anxiety disorder (SAD) and healthy controls, using VBM analysis. A total of 27 consecutive patients (15 women and 12 men) with SAD and 27 age and sex-matched healthy control subjects were included in this study. With magnetic resonance imaging, we examined GMV differences between SAD and healthy control groups. We found that GMV in the right middle and inferior temporal, left superior parietal, left precuneus and right fusiform areas were significantly greater in patients with SAD than in healthy controls. In addition, GMV in the right inferior and middle temporal regions were positively correlated with the social avoidance and total social anxiety scores of the participants in the SAD group. Lastly, greater GMV in the left superior parietal and precuneal regions were correlated with the higher disability in the social life of the patients with SAD. Our results suggest that the regions that showed significant GMV differences between the two groups play an important role in the pathophysiology of SAD and increased GMV in these regions might reflect a pathological process of neural abnormalities in this disorder.

Phosphorus magnetic resonance spectroscopy studies in schizophrenia.

Phosphorus magnetic resonance spectroscopy ((31)P MRS) allows in vivo quantification of phosphorus metabolites that are considered to be related to membrane turnover and energy metabolism. In schizophrenia (SZ), (31)P MRS studies found several abnormalities in different brain regions suggesting that alterations in these pathways may be contributing to the pathophysiology. In this paper, we systematically reviewed the (31)P MRS studies in SZ published to date by taking patient characteristics, medication status and brain regions into account. Publications written in English were searched on http://www.ncbi.nlm.nih.gov/pubmed/, by using the keywords 'phosphomonoester', 'phosphodiester', 'ATP', 'phosphocreatine', 'phosphocholine', 'phosphoethanolamine','glycerophosphocholine', 'glycerophosphoethanolamine', 'pH', 'schizophrenia', and 'MRS'. Studies that measured (31)P metabolites in SZ patients were included. This search identified 52 studies. Reduced PME and elevated PDE reported in earlier studies were not replicated in several subsequent studies. One relatively consistent pattern was a decrease in PDE in chronic patients in the subcortical structures. There were no consistent patterns for the comparison of energy related phosphorus metabolites between patients and controls. Also, no consistent pattern emerged in studies seeking relationship between (31)P metabolites and antipsychotic use and other clinical variables. Despite emerging patterns, methodological heterogeneities and shortcomings in this literature likely obscure consistent patterns among studies. We conclude with recommendations to improve study designs and (31)P MRS methods in future studies. We also stress the significance of probing into the dynamic changes in energy metabolism, as this approach reveals abnormalities that are not visible to steady-state measurements.

Age of onset in social anxiety disorder: Relation to clinical variables and major depression comorbidity.

BACKGROUND: The aim of this study was to determine the rates of early- and late-onset social anxiety disorder (SAD) and to investigate the effects of onset time on clinical characteristics and the course of SAD. METHODS: A total of 377 patients with SAD were assessed using a sociodemographic data form, the Liebowitz Social Anxiety Scale (LSAS), Beck Depression Inventory (BDI), and the Global Assessment of Functioning (GAF). Three hundred patients with SAD onset before age 18 were classified as members of the early-onset group, whereas 77 patients with SAD onset at age ≥ 18 comprised the late-onset group. The 2 groups were compared in terms of sociodemographic and clinical characteristics, comorbidity, and scale scores. RESULTS: The rate of SAD onset before age 18 was 79.6%. Compared with the late-onset group, the early-onset group had a younger age at first depressive episode, higher rate of atypical depression, higher LSAS and BDI scores, and lower GAF scores. CONCLUSIONS: In cases of early onset of SAD, symptom severity of both SAD and comorbid depression increased and functionality decreased. It is important to assess and treat SAD patients at a younger age because early-onset SAD may be associated with a more severe course and higher rate of major depression comorbidity.

Predominantly Inattentive Type of ADHD is Associated With Social Anxiety Disorder.

OBJECTIVE: The aim of this study was to determine the frequency of childhood ADHD comorbidity in patients with social anxiety disorder (SAD), and the influence of this comorbidity on various demographic and clinical variables in SAD. METHOD: A total of 130 patients with SAD were assessed with K-SADS-PL's (Schedule for Affective Disorders and Schizophrenia for School-Age Children-Present and Lifetime Version) behavioral disorders module to determine the childhood diagnosis of ADHD. Patients with or without a comorbid childhood ADHD were compared in terms of clinical characteristics and rating scores. RESULTS: The mean age at onset of SAD was lower, and lifetime major depressive disorder and bipolar disorder (BD) comorbidity were higher in the SAD-ADHD group than in the SAD-without ADHD group. CONCLUSION: We have found high ADHD comorbidity in patients with SAD. Presence of comorbid ADHD was associated with increased severity, functional impairment, and BD comorbidity.

Relationship between atypical depression and social anxiety disorder.

In this study, we aimed to investigate the effects of atypical and non-atypical depression comorbidity on the clinical characteristics and course of social anxiety disorder (SAD). A total of 247 patients with SAD were enrolled: 145 patients with a current depressive episode (unipolar or bipolar) with atypical features, 43 patients with a current depressive episode with non-atypical features and 25 patients without a lifetime history of depressive episodes were compared regarding sociodemographic and clinical features, comorbidity rates, and severity of SAD, depression and functional impairment. Thirty four patients with a past but not current history of major depressive episodes were excluded from the comparisons. 77.1% of current depressive episodes were associated with atypical features. Age at onset of SAD and age at initial major depressive episode were lower in the group with atypical depression than in the group with non-atypical depression. History of suicide attempts and bipolar disorder comorbidity was more common in the atypical depression group as well. Atypical depression group has higher SAD and depression severity and lower functionality than group with non-atypical depression. Our results indicate that the presence of atypical depression is associated with more severe symptoms and more impairment in functioning in patients with SAD.

The clinical impact of mood disorder comorbidity on social anxiety disorder.

BACKGROUND: High comorbidity rates of mood disorders have been reported in patients with social anxiety disorder (SAD). Our study aims to identify the frequency of comorbid Axis I disorders in patients with SAD and to investigate the impact of psychiatric comorbidity on SAD. METHODS: The study included 247 patients with SAD. Thirty eight patients with bipolar depression (SAD-BD), 150 patients with major depressive disorder (SAD-MDD) and 25 patients who do not have any mood disorder comorbidity (SAD-NOMD) were compared. RESULTS: Around 90% of SAD patients had at least one comorbid disorder. Comorbidity rates of lifetime MDD and BD were 74.5% and 15.4%, respectively. There was no comorbidity in the SAD-NOMD group. Atypical depression, total number of depressive episodes and rate of PTSD comorbidity were higher in SAD-BD than in SAD-MDD. Additionally, OCD comorbidity was higher in SAD-BD than in SAD-NOMD. SAD-MDD group had higher social anxiety severity than SAD-NOMD. CONCLUSIONS: Mood disorder comorbidity might be associated with increased severity and decreased functionality in patients with SAD.

Cognitive deficits in clinical and familial high risk groups for psychosis are common as in first episode schizophrenia.

The aim of this study is to compare the neurocognitive functions in individuals with clinical or genetic risk for psychosis, in patients with first-episode schizophrenia (FES) and in healthy controls. We compared cognitive functions of 52 individuals at ultra high risk (UHR) for psychosis, 53 patients with FES, their 30 healthy siblings (familial high risk group, FHR) and controls. FES group had worse neuropsychological performance than controls in all of the domains. UHR group had worse performance in verbal learning, attention, and working memory than controls. Additionally, individuals at UHR with familial risk had worse performance on executive functions than the control group. FES group had lower global composite score than UHR group, and worse sustained attention than FHR group. FHR group had worse performance on executive functions and attention than controls. We found no difference in cognitive performances of UHR and FHR groups. Cognitive deficits in UHR and FHR groups were largely similar to those with FES. These findings support that cognitive deficits may arise before the first episode of schizophrenia.

The history of childhood trauma among individuals with ultra high risk for psychosis is as common as among patients with first-episode schizophrenia.

AIM: Childhood trauma (CT) is more common in patients with psychosis than in general population and is found to be related to the severity of symptoms. The objective of this study was to investigate the severity of CT, and its relationship with clinical features in two different groups: first-episode schizophrenia (FES) and ultra high risk for psychosis (UHR) groups. METHODS: In this cross-sectional study, 83 patients with FES, 41 individuals with UHR and 69 healthy controls were included. Clinical features were evaluated with the Brief Psychiatric Rating Scale, the Scale for the Assessment of Negative Symptoms and the Scale for the Assessment of Positive Symptoms (SAPS). We evaluated CT with the Childhood Trauma Questionnaire (CTQ). UHR group was also assessed with the Calgary Depression Scale for Schizophrenia. RESULTS: The emotional and physical abuse, physical and emotionalneglect subscale scores and CTQ total score of both the UHR group and FES group were higher than the control group. However, the CTQ total score and subscale scores did not differ between FES and UHR groups. UHR group had more Schneiderian symptoms in terms of both number and severity, and severity of sexual abuse was found to be correlated with SAPS scores especially for the 'commenting voices' item. The CTQ emotional abuse and neglect scores were correlated with the severity of depression. FES patients with higher CTQ scores obtained higher total scores on SAPS and higher total scores on Schneiderian items. CONCLUSION: We found that CT is related to the severity of psychotic symptoms in both FES and UHR groups. Therefore, it is possible that interventions aimed at preventing CT in children would reduce the manifestation of psychosis among young people.

Gray matter volume in schizophrenia and bipolar disorder with psychotic features.

There is growing evidence that schizophrenia (SZ) and bipolar disorder (BD) overlap significantly in risk factors, neurobiological features, clinical presentations, and outcomes. SZ is characterized by well documented gray matter (GM) abnormalities in multiple frontal, temporal and subcortical structures. Recent voxel-based morphometry (VBM) studies and meta-analyses in BD also report GM reductions in overlapping, albeit less widespread, brain regions. Psychosis, a hallmark of SZ, is also experienced by a significant proportion of BD patients and there is evidence that psychotic BD may be characterized by specific clinical and pathophysiological features. However, there are few studies comparing GM between SZ and psychotic BD. In this study we compared GM volumes in a sample of 58 SZ patients, 28 BD patients experiencing psychotic symptoms and 43 healthy controls using whole-brain voxel-based morphometry. SZ patients had GM reductions in multiple frontal and temporal regions compared to healthy controls and in the subgenual cortex compared to psychotic BD patients. GM volume was increased in the right posterior cerebellum in SZ patients compared to controls. However, psychotic BD patients did not show significant GM deficits compared to healthy controls or SZ patients. We conclude that GM abnormality as measured by VBM analysis is less pronounced in psychotic BD compared to SZ. This may be due to disease-specific factors or medications used more commonly in BD.