Training volitional control of the theory of mind network with real-time fMRI neurofeedback.

Is there a way improve our ability to understand the minds of others? Towards addressing this question, here, we conducted a single-arm, proof-of-concept study to evaluate whether real-time fMRI neurofeedback (rtfMRI-NF) from the temporo-parietal junction (TPJ) leads to volitional control of the neural network subserving theory of mind (ToM; the process by which we attribute and reason about the mental states of others). As additional aims, we evaluated the strategies used to self-regulate the network and whether volitional control of the ToM network was moderated by participant characteristics and associated with improved performance on behavioral measures. Sixteen participants underwent fMRI while completing a task designed to individually-localize the TPJ, and then three separate rtfMRI-NF scans during which they completed multiple runs of a training task while receiving intermittent, activation-based feedback from the TPJ, and one run of a transfer task in which no neurofeedback was provided. Region-of-interest analyses demonstrated volitional control in most regions during the training tasks and during the transfer task, although the effects were smaller in magnitude and not observed in one of the neurofeedback targets for the transfer task. Text analysis demonstrated that volitional control was most strongly associated with thinking about prior social experiences when up-regulating the neural signal. Analysis of behavioral performance and brain-behavior associations largely did not reveal behavior changes except for a positive association between volitional control in RTPJ and changes in performance on one ToM task. Exploratory analysis suggested neurofeedback-related learning occurred, although some degree of volitional control appeared to be conferred with the initial self-regulation strategy provided to participants (i.e., without the neurofeedback signal). Critical study limitations include the lack of a control group and pre-rtfMRI transfer scan, which prevents a more direct assessment of neurofeedback-induced volitional control, and a small sample size, which may have led to an overestimate and/or unreliable estimate of study effects. Nonetheless, together, this study demonstrates the feasibility of training volitional control of a social cognitive brain network, which may have important clinical applications. Given the study's limitations, findings from this study should be replicated with more robust experimental designs.

The kynurenine pathway and bipolar disorder: intersection of the monoaminergic and glutamatergic systems and immune response.

Dysfunction in a wide array of systems-including the immune, monoaminergic, and glutamatergic systems-is implicated in the pathophysiology of depression. One potential intersection point for these three systems is the kynurenine (KYN) pathway. This study explored the impact of the prototypic glutamatergic modulator ketamine on the endogenous KYN pathway in individuals with bipolar depression (BD), as well as the relationship between response to ketamine and depression-related behavioral and peripheral inflammatory markers. Thirty-nine participants with treatment-resistant BD (23 F, ages 18-65) received a single ketamine infusion (0.5 mg/kg) over 40 min. KYN pathway analytes-including plasma concentrations of indoleamine 2,3-dioxygenase (IDO), KYN, kynurenic acid (KynA), and quinolinic acid (QA)-were assessed at baseline (pre-infusion), 230 min, day 1, and day 3 post-ketamine. General linear models with restricted maximum likelihood estimation and robust sandwich variance estimators were implemented. A repeated effect of time was used to model the covariance of the residuals with an unstructured matrix. After controlling for age, sex, and body mass index (BMI), post-ketamine IDO levels were significantly lower than baseline at all three time points. Conversely, ketamine treatment significantly increased KYN and KynA levels at days 1 and 3 versus baseline. No change in QA levels was observed post-ketamine. A lower post-ketamine ratio of QA/KYN was observed at day 1. In addition, baseline levels of proinflammatory cytokines and behavioral measures predicted KYN pathway changes post ketamine. The results suggest that, in addition to having rapid and sustained antidepressant effects in BD participants, ketamine also impacts key components of the KYN pathway.

Symptom trajectories in the months before and after a suicide attempt in individuals with bipolar disorder: A STEP-BD study.

OBJECTIVES: The suicide crisis is a relatively short-lived psychiatric emergency, with transient symptoms that ebb and flow around the suicide attempt. Understanding the dynamic processes of symptoms before and after suicide attempt may aid future prevention efforts. METHODS: Data were drawn from the NIMH STEP-BD study, which followed 4,360 patients with bipolar disorder; a subset attempted suicide during the trial (245/4100 or 5.97% of the sample eligible for analysis). This analysis focused on change in suicidal ideation (SI) in the 120 days before and 120 days after suicide attempt; similar analyses were conducted for other depressive symptoms. Generalized linear mixed models with a two-piece linear function of time corresponding to pre- and post-suicide attempt trends were used. RESULTS: SI ratings from 216 individuals were analyzed (n = 1,231 total; n = 395 pre-attempt, n = 126 circa-attempt, n = 710 post-attempt) and compared to data from a matched sample of 648 non-attempters. SI worsened in the 120 days pre-attempt but improved afterwards, reaching non-attempter levels by 90 days post-attempt. A similar pattern was found for other depressive symptoms, including depressed mood, loss of interest, guilt, and self-esteem. Pre/post differences in tension/activating symptoms of depression-anxiety, agitation, and irritability-were less pronounced and more time-limited. CONCLUSIONS: The suicide crisis is dynamic, and the days before and after suicide attempt may be particularly critical. The findings extend previous research on proximal symptoms of suicide and underscore that some SI and affective/cognitive symptoms of depression can remain elevated up to 90 days post-attempt in individuals with bipolar disorder.

Decision-making under risk and its correlates in schizophrenia.

Schizophrenia spectrum disorders (SSD) are associated with pervasive cognitive impairments, including deficits in decision-making under risk. However, there is inconclusive evidence regarding specific mechanisms underlying altered decision-making patterns. In this study, participants (33 SSD and 28 non-SSD) completed the Columbia Card Task, an explicit risk-taking task, to better understand risk preference and adjustment in dynamic decision-making. We found that while there is no group difference in overall risk-taking, risk preference, or optimal decision-making, risk adjustment to contextual factors (e.g., loss probability) is blunted in SSD. We also found associations between risk-taking/suboptimal decision-making and disorganized symptoms, excited symptoms, and role functioning, but no associations between decision-making and working memory. These results suggest that during a complex, dynamic risk-taking task, individuals with SSD exhibit less adaption to changing information about risk, which may reflect risk imperception.

Social affective forecasting and social anhedonia in schizophrenia-spectrum disorders: a daily diary study.

Social anhedonia (SA) is a trait-like phenomenon observed across schizophrenia-spectrum disorders (SSDs). While in-the-moment social pleasure experiences are intact in SSDs, anticipatory pleasure experiences may be disrupted. Thus, the prediction of future emotions in social situations, or social affective forecasting (SAF), may play a role in SA. Therefore, we utilized daily diary methods to examine SAF in SSD and the association between SAF and SA in 34 SSD and 43 non-SSD individuals. SAF was calculated as the absolute difference between anticipatory and consummatory ratings of 13 positive and negative emotions for daily social interactions reported across eight days. Results suggest that individuals with SSDs are less accurate in forecasting negative, but not positive emotions, for future social interactions. Further, poorer forecasting accuracy of negative emotions were associated with elevated levels of SA and lower social pleasure. Together, these data suggest that inaccuracies in forecasting negative emotions may be a worthwhile intervention target for reducing SA in SSDs.

Risk factors for loneliness: The high relative importance of age versus other factors.

Loneliness is a potent predictor of negative health outcomes, making it important to identify risk factors for loneliness. Though extant studies have identified characteristics associated with loneliness, less is known about the cumulative and relative importance of these factors, and how their interaction may impact loneliness. Here, 4,885 individuals ages 10-97 years from the US completed the three-item UCLA Loneliness Survey on TestMyBrain.org. Using census data, we calculated the population and community household income of participants' census area, and the proportion of individuals in the participant's census area that shared the participant's demographic characteristics (i.e., sociodemographic density). We evaluated the relative importance of three classes of variables for loneliness risk: those related to the person (e.g., age), place (e.g., community household income), and the interaction of person X place (sociodemographic density). We find that loneliness is highly prevalent and best explained by person (age) and place (community household income) characteristics. Of the variance in loneliness accounted for, the overwhelming majority was explained by age with loneliness peaking at 19 years and declining thereafter. The congruence between one's sociodemographic characteristics and that of one's neighborhood had no impact on loneliness. These data may have important implications for public health interventions.

Social anhedonia, social networks, and psychotic-like experiences: A test of social deafferentation.

Social connection is robustly associated with physical and mental health. So important is social connection that it features prominently in several etiological theories of serious psychopathology. Most notably, the social deafferentation hypothesis of schizophrenia posits that social anhedonia (SA) and isolation cause neural changes that produce psychosis. Here, we test several tenants of this theory by examining the relation between SA, psychotic-like experiences (PLE), and social networks. We find that SA and PLE are related to social networks, and that the relation between SA and PLE can be explained, in part, by the impact of SA on social networks.

Features of dissociation differentially predict antidepressant response to ketamine in treatment-resistant depression.

BACKGROUND: Ketamine induces rapid and robust antidepressant effects, and many patients also describe dissociation, which is associated with antidepressant response. This follow-up study investigated whether antidepressant efficacy is uniquely related to dissociative symptom clusters. METHODS: Treatment-resistant patients with major depressive disorder (MDD) or bipolar disorder (BD) (n = 126) drawn from three studies received a single subanesthetic (0.5 mg/kg) ketamine infusion. Dissociative effects were measured using the Clinician-Administered Dissociative States Scale (CADSS). Antidepressant response was measured using the 17-item Hamilton Depression Rating Scale (HAM-D). A confirmatory factor analysis established the validity of CADSS subscales (derealization, depersonalization, amnesia), and a general linear model with repeated measures was fitted to test whether subscale scores were associated with antidepressant response. RESULTS: Factor validity was supported, with a root mean square error of approximation of .06, a comparative fit index of .97, and a Tucker-Lewis index of .96. Across all studies and timepoints, the depersonalization subscale was positively related to HAM-D percent change. A significant effect of derealization on HAM-D percent change was observed at one timepoint (Day 7) in one study. The amnesia subscale was unrelated to HAM-D percent change. LIMITATIONS: Possible inadequate blinding; combined MDD/BD datasets might have underrepresented ketamine's antidepressant efficacy; the possibility of Type I errors in secondary analyses. CONCLUSIONS: From a psychometric perspective, researchers may elect to administer only the CADSS depersonalization subscale, given that it was most closely related to antidepressant response. From a neurobiological perspective, mechanistic similarities may exist between ketamine-induced depersonalization and antidepressant response, although off-target effects cannot be excluded.