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1.
Psychol Med ; 52(5): 864-873, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-32698918

RESUMO

BACKGROUND: Given the prevalence of adolescent depression and the modest effects of current treatments, research ought to inform development of effective intervention strategies. Self-compassion is inversely associated with depression, and self-compassion interventions have demonstrated promising effects on reducing depression. However, little is known about the neural mechanisms underlying that relationship. Maladaptive self-processing is a characteristic of depression that contributes to the onset and chronicity of depression. Because our own face is an automatic and direct cue for self-processing, this study investigated whether self-compassion was associated with neural responses during sad v. neutral self-face recognition and explore their relationship with depression severity in depressed adolescents and healthy controls (HCs). METHODS: During functional magnetic resonance imaging, 81 depressed youth and 37 HCs were instructed to identify whether morphed self or other faces with sad, happy, or neutral expressions resembled their own. RESULTS: Self-compassion correlated negatively with activity during sad v. neutral self-face recognition in the dorsal anterior cingulate cortex in the total sample, and in the right posterior cingulate cortex/precuneus in HCs, respectively. In depressed adolescents, higher self-compassion correlated with lower activity during sad v. neutral self-face recognition in the right dorsolateral prefrontal cortex (DLPFC), implying that less cognitive effort might be needed to avoid dwelling on sad self-faces and/or regulate negative affect induced by them. Moreover, higher self-compassion mediated the relationship between lower DLPFC activity and reduced depression severity. CONCLUSIONS: Our findings imply that DLPFC activity might be a biological marker of a successful self-compassion intervention as potential treatment for adolescent depression.


Assuntos
Reconhecimento Facial , Adolescente , Córtex Pré-Frontal Dorsolateral , Emoções/fisiologia , Expressão Facial , Reconhecimento Facial/fisiologia , Humanos , Imageamento por Ressonância Magnética/métodos , Córtex Pré-Frontal/diagnóstico por imagem , Autocompaixão
2.
Clin Infect Dis ; 73(7): e2303-e2310, 2021 10 05.
Artigo em Inglês | MEDLINE | ID: mdl-33053187

RESUMO

BACKGROUND: Age, human immunodeficiency virus (HIV) infection, illicit drug use, and central nervous system (CNS) opportunistic infections can affect brain structure, with the striatum being particularly sensitive to HIV effects. Nevertheless, the impact of non-CNS AIDS-defining illness (ADI) on brain structure has been less investigated. We examined ADI and HIV effects on brain volume. METHODS: In a cross-sectional study, including 95 virally suppressed seropositive and 84 demographically matched, seronegative participants, we examined serostatus and ADI effects. Cortical and subcortical gray matter volume (GMV) regions of interest were estimated with computational neuroanatomy techniques applied to high-resolution, T1-weighted magnetic resonance imaging data. Linear regression was used to model HIV serostatus and ADI effects on global and regional GMV, adjusting for age, sex, CD4 nadir, drug use, and total intracranial volume. RESULTS: While HIV serostatus was associated with lower striatal volume (B = -.59 [95% confidence interval {CI}, -1.08 to -.10]), co-occurring ADI was independently associated with lower striatal volume (B = -.73 [95% CI, -1.36 to -.09]). ADI was also associated with lower global (B = -19.35 [95% CI, -32.42 to -6.29]) and regional GMV. CONCLUSIONS: While HIV infection is associated with a localized effect on striatal structure, having a prior ADI is a strong predictor of smaller global and regional GMV. The lack of interaction between HIV serostatus or ADI with age suggests that chronic HIV infection and ADI have independent effects on brain structure, without associated accelerated lower volume with age. ADI history should be incorporated into statistical adjustments in HIV neuroimaging analysis. These findings also lend support to current HIV treatment guidelines urging prompt antiretroviral therapy initiation after HIV diagnosis.


Assuntos
Síndrome da Imunodeficiência Adquirida , Infecções por HIV , Encéfalo/diagnóstico por imagem , Estudos Transversais , Substância Cinzenta/diagnóstico por imagem , Infecções por HIV/complicações , Humanos , Imageamento por Ressonância Magnética , Neuroimagem
3.
Int J Obes (Lond) ; 44(8): 1636-1652, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32555497

RESUMO

OBJECTIVE: Consuming sweet foods, even when sated, can lead to unwanted weight gain. Contextual factors, such as longer time fasting, subjective hunger, and body mass index (BMI), may increase the likelihood of overeating. Nevertheless, the neural mechanisms underlying these moderating influences on energy intake are poorly understood. METHODS: We conducted both categorical meta-analysis and meta-regression of factors modulating neural responses to sweet stimuli, using data from 30 functional magnetic resonance imaging (fMRI) articles incorporating 39 experiments (N = 995) carried out between 2006 and 2019. RESULTS: Responses to sweet stimuli were associated with increased activity in regions associated with taste, sensory integration, and reward processing. These taste-evoked responses were modulated by context. Longer fasts were associated with higher posterior cerebellar, thalamic, and striatal activity. Greater self-reported hunger was associated with higher medial orbitofrontal cortex (OFC), dorsal striatum, and amygdala activity and lower posterior cerebellar activity. Higher BMI was associated with higher posterior cerebellar and insular activity. CONCLUSIONS: Variations in fasting time, self-reported hunger, and BMI are contexts associated with differential sweet stimulus responses in regions associated with reward processing and homeostatic regulation. These results are broadly consistent with a hierarchical model of taste processing. Hunger, but not fasting or BMI, was associated with sweet stimulus-related OFC activity. Our findings extend existing models of taste processing to include posterior cerebellar regions that are associated with moderating effects of both state (fast length and self-reported hunger) and trait (BMI) variables.


Assuntos
Índice de Massa Corporal , Sacarose Alimentar/administração & dosagem , Fome , Encéfalo/fisiologia , Ingestão de Energia , Humanos , Imageamento por Ressonância Magnética , Recompensa , Paladar
4.
J Neurovirol ; 25(4): 480-495, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31028692

RESUMO

The age of the HIV-infected population is increasing. Although many studies document gray matter volume (GMV) changes following HIV infection, GMV also declines with age. Findings have been inconsistent concerning interactions between HIV infection and age on brain structure. Effects of age, substance use, and inadequate viral suppression may confound identification of GMV serostatus effects using quantitative structural measures. In a cross-sectional study of HIV infection, including 97 seropositive and 84 seronegative, demographically matched participants, ages 30-70, we examined serostatus and age effects on GMV and neuropsychological measures. Ninety-eight percent of seropositive participants were currently treated with anti-retroviral therapies and all were virally suppressed. Gray, white, and CSF volumes were estimated using high-resolution T1-weighted MRI. Linear regression modeled effects of serostatus, age, education, comorbidities, and magnetic field strength on brain structure, using both a priori regions and voxel-based morphometry. Although seropositive participants exhibited significant bilateral decreases in striatal GMV, no serostatus effects were detected in the thalamus, hippocampus, or cerebellum. Age was associated with cortical, striatal, thalamic, hippocampal, and cerebellar GMV reductions. Effects of age and serostatus on striatal GMV were additive. Although no main effects of serostatus on neuropsychological performance were observed, serostatus moderated the relationship between pegboard performance and striatal volume. Both HIV infection and age were associated with reduced striatal volume. The lack of interaction of these two predictors suggests that HIV infection is associated with premature, but not accelerated, brain age. In serostatus groups matched on demographic and clinical variables, there were no observed differences in neuropsychological performance. Striatal GMV measures may be promising biomarker for use in studies of treated HIV infection.


Assuntos
Envelhecimento/patologia , Corpo Estriado/patologia , Substância Cinzenta/patologia , Infecções por HIV/patologia , Hipocampo/patologia , Lobo Temporal/patologia , Tálamo/patologia , Adulto , Fatores Etários , Idoso , Envelhecimento/efeitos dos fármacos , Fármacos Anti-HIV/uso terapêutico , Terapia Antirretroviral de Alta Atividade , Mapeamento Encefálico , Estudos de Casos e Controles , Corpo Estriado/diagnóstico por imagem , Corpo Estriado/efeitos dos fármacos , Corpo Estriado/virologia , Feminino , Substância Cinzenta/diagnóstico por imagem , Substância Cinzenta/efeitos dos fármacos , Substância Cinzenta/virologia , Infecções por HIV/diagnóstico por imagem , Infecções por HIV/tratamento farmacológico , Infecções por HIV/virologia , Hipocampo/diagnóstico por imagem , Hipocampo/efeitos dos fármacos , Hipocampo/virologia , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Neuroimagem , Testes Neuropsicológicos , Lobo Temporal/diagnóstico por imagem , Lobo Temporal/efeitos dos fármacos , Lobo Temporal/virologia , Tálamo/diagnóstico por imagem , Tálamo/efeitos dos fármacos , Tálamo/virologia , Substância Branca/diagnóstico por imagem , Substância Branca/efeitos dos fármacos , Substância Branca/patologia , Substância Branca/virologia
5.
J Neurol Phys Ther ; 41(3): 164-172, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28628550

RESUMO

BACKGROUND AND PURPOSE: Spontaneous visual recovery is rare after cortical blindness. While visual rehabilitation may improve performance, no visual therapy has been widely adopted, as clinical outcomes are variable and rarely translate into improvements in activities of daily living (ADLs). We explored the potential value of a novel rehabilitation approach "cognitive therapeutic exercises" for cortical blindness. CASE DESCRIPTION: The subject of this case study was 48-year-old woman with cortical blindness and tetraplegia after cardiac arrest. Prior to the intervention, she was dependent in ADLs and poorly distinguished shapes and colors after 19 months of standard visual and motor rehabilitation. Computed tomographic images soon after symptom onset demonstrated acute infarcts in both occipital cortices. INTERVENTION: The subject underwent 8 months of intensive rehabilitation with "cognitive therapeutic exercises" consisting of discrimination exercises correlating sensory and visual information. OUTCOMES: Visual fields increased; object recognition improved; it became possible to watch television; voluntary arm movements improved in accuracy and smoothness; walking improved; and ADL independence and self-reliance increased. Subtraction of neuroimaging acquired before and after rehabilitation showed that focal glucose metabolism increases bilaterally in the occipital poles. DISCUSSION: This study demonstrates feasibility of "cognitive therapeutic exercises" in an individual with cortical blindness, who experienced impressive visual and sensorimotor recovery, with marked ADL improvement, more than 2 years after ischemic cortical damage.Video Abstract available for additional insights from the authors (see Video, Supplemental Digital Content 1, available at: http://links.lww.com/JNPT/A173).


Assuntos
Cegueira Cortical/psicologia , Cegueira Cortical/reabilitação , Terapia Cognitivo-Comportamental , Terapia por Exercício , Atividades Cotidianas , Cegueira Cortical/fisiopatologia , Feminino , Humanos , Pessoa de Meia-Idade , Recuperação de Função Fisiológica , Visão Ocular , Caminhada
6.
J Child Psychol Psychiatry ; 57(4): 510-9, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26472591

RESUMO

BACKGROUND: Deficient empathic processing is thought to foster conduct disorder (CD). It is important to determine the extent to which neural response associated with perceiving harm to others predicts CD symptoms and callous disregard for others. METHODS: A total of 107 9- to 11-year-old children (52 female) were recruited from pediatric and mental health clinics, representing a wide range of CD symptoms. Children were scanned with functional magnetic resonance imaging while viewing brief video clips of persons being harmed intentionally or accidentally. RESULTS: Perceiving harm evoked increased hemodynamic response in the anterior insula (aINS), anterior cingulate cortex (ACC), amygdala, periaqueductal gray (PAG), caudate, and inferior parietal lobe (IPL) across all participants. Intentionally caused, relative to unintentional harm was associated with greater activity in the aINS, amygdala, and temporal pole. There was an inverse association of number of CD symptoms with right posterior insula in both the Harm > No Harm and the Intentional > Unintentional Harm contrasts. Furthermore, an inverse association between callousness and posterior insula activation was found in the Harm > No Harm contrast, with the opposite pattern for reactive aggression scores. An interaction revealed a stronger association in girls between CD symptoms and the right posterior superior temporal sulcus (pSTS) in the Intentional Harm versus Unintentional Harm contrast. CONCLUSIONS: Children with greater CD and callousness exhibit dampened hemodynamic response to viewing others being harmed in the insula, a region which plays a key role in empathy and emotional awareness. Sex differences in the neural correlates of CD were observed.


Assuntos
Mapeamento Encefálico/métodos , Encéfalo/fisiopatologia , Córtex Cerebral/fisiopatologia , Transtorno da Conduta/fisiopatologia , Empatia/fisiologia , Criança , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Fatores Sexuais
7.
Int J Eat Disord ; 49(7): 701-7, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27037965

RESUMO

OBJECTIVE: We examined the preliminary acceptability and efficacy of family-based therapy (FBT) for weight restoration in young adults (FBTY) with Anorexia Nervosa (AN). METHOD: Twenty-two primarily female participants ranging from age 18 to 26, with AN or atypical AN (ICD-10) and their support adults were enrolled in a 6-month open trial of FBTY. Participants were assessed at baseline, after treatment, and at six and 12 month follow-up visits. The primary outcome was BMI and secondary outcomes included eating disorder psychopathology, current eating disorder obsessions, and compulsions, number of other Axis I disorders and global assessment of functioning. RESULTS: Although FBTY was rated as suitable by participants and their support adults, during FBTY, 9/22 participants dropped out and 3/22 dropped out at follow-up assessments. Despite being offered 18-20 sessions over six months, a mean of 12 FBTY sessions (SD = 6) were attended. After FBTY, 15 of the intent-to-treat sample of 22 were no longer underweight (BMIs ≥ 19 kg/m(2) ) and 12 months after treatment, 13/22 were no longer underweight. The magnitude of the BMI increase during FBTY (Hedges g = 1.20, 95th percentile CI = 0.55-1.85) was comparable to findings for adolescent FBT for AN. Secondary outcomes also improved. DISCUSSION: FBTY for young adults with AN and atypical AN, which involves support adults participants have chosen, results in weight restoration that is sustained up to a year after treatment. © 2016 Wiley Periodicals, Inc. (Int J Eat Disord 2016; 49:701-707).


Assuntos
Anorexia Nervosa/terapia , Terapia Familiar , Adolescente , Adulto , Anorexia Nervosa/fisiopatologia , Índice de Massa Corporal , Feminino , Humanos , Masculino , Resultado do Tratamento , Aumento de Peso , Adulto Jovem
8.
Cogn Affect Behav Neurosci ; 15(3): 712-20, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25904238

RESUMO

Meditation has been associated with relatively reduced activity in the default mode network, a brain network implicated in self-related thinking and mind wandering. However, previous imaging studies have typically compared meditation to rest, despite other studies having reported differences in brain activation patterns between meditators and controls at rest. Moreover, rest is associated with a range of brain activation patterns across individuals that has only recently begun to be better characterized. Therefore, in this study we compared meditation to another active cognitive task, both to replicate the findings that meditation is associated with relatively reduced default mode network activity and to extend these findings by testing whether default mode activity was reduced during meditation, beyond the typical reductions observed during effortful tasks. In addition, prior studies had used small groups, whereas in the present study we tested these hypotheses in a larger group. The results indicated that meditation is associated with reduced activations in the default mode network, relative to an active task, for meditators as compared to controls. Regions of the default mode network showing a Group × Task interaction included the posterior cingulate/precuneus and anterior cingulate cortex. These findings replicate and extend prior work indicating that the suppression of default mode processing may represent a central neural process in long-term meditation, and they suggest that meditation leads to relatively reduced default mode processing beyond that observed during another active cognitive task.


Assuntos
Encéfalo/fisiologia , Meditação , Adulto , Mapeamento Encefálico , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Vias Neurais/fisiologia , Testes Neuropsicológicos , Descanso
9.
Int J Eat Disord ; 48(1): 123-32, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25346237

RESUMO

OBJECTIVE: Anorexia Nervosa (AN) is associated with excessive self-control. This iterative case series describes the augmentation of Dialectical Behavior Therapy (DBT) for outpatient adult AN with skills addressing emotional and behavioral overcontrol. An overly controlled style is theorized to develop from the transaction between an individual with heightened threat sensitivity and reduced reward sensitivity, interacting with an environment reinforcing overcontrol and punishing imperfection. METHOD: Case Series 1 utilized standard DBT, resulting in retention of 5/6 patients and a body mass index (BMI) effect size increase of d = -0.5 from pre- to post-treatment. Case series 2, using standard DBT augmented with skills addressing overcontrol, resulted in retention of 8/9 patients with an effect size increase in BMI at post-treatment that was maintained at 6- and 12-months follow-up (d = -1.12, d = -0.87, and d = -1.12). DISCUSSION: Findings suggest that skills training targeting rigidity and increasing openness and social connectedness warrant further study of this model and treatment for AN.


Assuntos
Anorexia Nervosa/terapia , Terapia Comportamental/métodos , Adulto , Assistência Ambulatorial , Anorexia Nervosa/psicologia , Índice de Massa Corporal , Emoções , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Projetos de Pesquisa , Adulto Jovem
10.
Stroke ; 45(4): 1077-83, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24525953

RESUMO

BACKGROUND AND PURPOSE: Although neuroimaging studies have revealed specific patterns of reorganization in the sensorimotor control network after stroke, their role in recovery remains unsettled. To review the existing evidence systematically, we performed activation likelihood estimation meta-analysis of functional neuroimaging studies investigating upper limb movement-related brain activity after stroke. METHODS: Twenty-four studies using sensorimotor tasks in standardized coordinates were included, totaling 255 patients and 145 healthy controls. Across the entire brain, we compared task-related activity patterns in good and poor recovery and assessed the magnitude of spatial shifts in sensorimotor activity in cortical motor areas after stroke. RESULTS: When compared with healthy controls, patients showed higher activation likelihood estimation values in contralesional primary motor soon after stroke that abated with time, but were not related to motor outcome. The observed activity changes were consistent with restoration of typical interhemispheric balance. In contrast, activation likelihood estimation values in ipsilesional medial-premotor and primary motor cortex were associated with good outcome, reorganization that may reflect vicarious processes associated with ventral activity shifts from BA4a to 4p. In the anterior cerebellum, a novel finding was the association of poor recovery with increased vermal activity, possibly reflecting behaviorally inadequate compensatory strategies engaging the fastigio-thalamo-cortical and corticoreticulospinal systems. CONCLUSIONS: Activity in ipsilesional primary motor and medial-premotor cortices in chronic stroke signals good motor recovery, whereas cerebellar vermis activity signals poor recovery. Functional MRI may be useful in identifying recovery biomarkers.


Assuntos
Braço/fisiologia , Córtex Motor/fisiologia , Transtornos dos Movimentos/fisiopatologia , Recuperação de Função Fisiológica/fisiologia , Acidente Vascular Cerebral/fisiopatologia , Isquemia Encefálica/fisiopatologia , Cerebelo/fisiopatologia , Doença Crônica , Feminino , Lateralidade Funcional/fisiologia , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Movimento/fisiologia , Córtex Somatossensorial/fisiologia , Fatores de Tempo
11.
Artigo em Inglês | MEDLINE | ID: mdl-39389778

RESUMO

BACKGROUND AND PURPOSE: Neuropsychiatric complications of SARS-CoV-2 infection, also known as neurologic postacute sequelae of SARS-CoV-2 infection (NeuroPASC), affect 10%-60% of infected individuals. There is growing evidence that NeuroPASC is a multi system immune dysregulation disease affecting the brain. The behavioral manifestations of NeuroPASC, such as impaired processing speed, executive function, memory retrieval, and sustained attention, suggest widespread WM involvement. Although previous work has documented WM damage following acute SARS-CoV-2 infection, its involvement in NeuroPASC is less clear. We hypothesized that macrostructural and microstructural WM differences in NeuroPASC participants would accompany cognitive and immune system differences. MATERIALS AND METHODS: In a cross-sectional study, we screened a total of 159 potential participants and enrolled 72 participants, with 41 asymptomatic controls (NoCOVID) and 31 NeuroPASC participants matched for age, sex, and education. Exclusion criteria included neurologic disorders unrelated to SARS-CoV-2 infection. Assessments included clinical symptom questionnaires, psychometric tests, brain MRI measures, and peripheral cytokine levels. Statistical modeling included separate multivariable regression analyses of GM/WM/CSF volume, WM microstructure, cognitive, and cytokine concentration between-group differences. RESULTS: NeuroPASC participants had larger cerebral WM volume than NoCOVID controls (ß = 0.229; 95% CI: 0.017-0.441; t = 2.16; P = .035). The most pronounced effects were in the prefrontal and anterior temporal WM. NeuroPASC participants also exhibited higher WM mean kurtosis, consistent with ongoing neuroinflammation. NeuroPASC participants had more self-reported symptoms, including headache, and lower performance on measures of attention, concentration, verbal learning, and processing speed. A multivariate profile analysis of the cytokine panel showed different group cytokine profiles (Wald-type-statistic = 44.6, P = .046), with interferon (IFN)-λ1 and IFN-λ2/3 levels higher in the NeuroPASC group. CONCLUSIONS: NeuroPASC participants reported symptoms of lower concentration, higher fatigue, and impaired cognition compatible with WM syndrome. Psychometric testing confirmed these findings. NeuroPASC participants exhibited larger cerebral WM volume and higher WM mean kurtosis than NoCOVID controls. These findings suggest that immune dysregulation could influence WM properties to produce WM volume increases and consequent cognitive effects and headaches. Further work will be needed to establish mechanistic links among these variables.

12.
J Psychiatr Res ; 177: 361-367, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39083994

RESUMO

Effective attention control is essential for behavioral adaptation to different environmental contexts. In Post-traumatic Stress Disorder (PTSD) altered attention has been described in trauma-related and other emotional contexts. Nevertheless, atypical attention is also seen with neutral stimuli. The mechanisms of attention alterations in PTSD associated with neutral stimuli are poorly understood. The present study investigates alerting and orienting responses in PTSD participants using emotionally neutral stimuli in a saccade eye movement task incorporating both spatially predictable and temporally unpredictable conditions. We studied 23 PTSD patients and 27 Non-PTSD controls, using repeated-measures mixed modeling to estimate group and task condition differences in behavioral and psychophysiological measures. We explored the relationships among saccade characteristics, pupil size, and PTSD symptoms, including CAPS hypervigilance scores. PTSD, compared to Non-PTSD, participants showed differences in their saccade 'main sequence', reflected by higher peak velocities adjusted for amplitude. PTSD participants had smaller primary position errors in the unpredictable saccade condition. They also exhibited greater hyperarousal, reflected by larger pupil size during fixation that was greater in the unpredictable condition. Our results suggest that a heightened state of arousal and hypervigilance in PTSD leads to a state of atypical attention bias, even in emotionally neutral contexts. These differences may reflect higher saccade vigor. The observed differences suggest atypical attention in PTSD, which goes beyond possible distraction associated with emotional or threat-related stimuli.


Assuntos
Atenção , Movimentos Sacádicos , Transtornos de Estresse Pós-Traumáticos , Humanos , Transtornos de Estresse Pós-Traumáticos/fisiopatologia , Movimentos Sacádicos/fisiologia , Feminino , Masculino , Adulto , Atenção/fisiologia , Pessoa de Meia-Idade , Adulto Jovem , Pupila/fisiologia , Nível de Alerta/fisiologia
13.
Schizophr Bull ; 2024 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-38900958

RESUMO

BACKGROUND AND HYPOTHESIS: Up to 43% of people with schizophrenia have a lifetime cannabis use disorder (CUD). Tetrahydrocannabinol (THC) has been shown to exacerbate psychosis in a dose-dependent manner, but little research has assessed its effects on schizophrenia and co-occurring CUD (SCZ-CUD). In this double-dummy, placebo-controlled trial (total n = 130), we hypothesized that a modest dose of THC would worsen cognitive function but not psychosis. STUDY DESIGN: Effects of single-dose oral THC (15 mg dronabinol) or smoked 3.5% THC cigarettes vs placebo in SCZ-CUD or CUD-only on positive and negative symptoms of schizophrenia (only for SCZ-CUD), cognition, and drug experiences assessed several hours after drug administration. SCZ-only and healthy control participants were also assessed. STUDY RESULTS: Drug liking was higher in THC groups vs placebo. Neither smoked THC nor oral dronabinol predicted positive or negative symptom subscale scores 2 and 5 h, respectively, after drug exposure in SCZ-CUD participants. The oral dronabinol SCZ-CUD group, but not smoked THC SCZ-CUD group, performed worse than placebo on verbal learning (B = -9.89; 95% CI: -16.06, -3.18; P = .004) and attention (B = -0.61; 95% CI: -1.00, -0.23; P = .002). Every 10-point increment in serum THC + THCC ng/ml was associated with increased negative symptoms (0.40 points; 95% CI: 0.15, 0.65; P = .001; subscale ranges 7-49) and trends were observed for worse positive symptoms and performance in verbal learning, delayed recall, and working memory. CONCLUSIONS: In people with SCZ-CUD, a modest single dose of oral THC was associated with worse cognitive functioning without symptom exacerbation several hours after administration, and a THC dose-response effect was seen for negative symptoms.

14.
medRxiv ; 2024 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-39185528

RESUMO

While nitrous oxide (N2O) has demonstrated antidepressant properties in treatment-resistant major depression (TRD), little is known about neural mechanisms mediating these effects. Employing serial resting-state functional magnetic resonance imaging (rs-fMRI), we compared spatiotemporal effects of inhaled N2O on brain functional connectivity in TRD patients (n=14) and non-depressed healthy controls (n=16, CNTL). Participants received sequential, one-hour inhalations of either 50% N2O/oxygen or air/oxygen (placebo), with sessions separated by at least one month in random cross-over order. BOLD-contrast rs-fMRI scans were acquired at three time points: pre-inhalation, 2 hours post-inhalation, and 24 hours post-inhalation. For the rs-fMRI functional connectivity analyses, five a priori seeds in medial limbic structures targeted cortical networks implicated in major depression - the salience, anterior and posterior default mode, reward, and cingulo-opercular networks - and a nexus in the dorsal paracingulate region previously identified in MDD ("dorsal nexus"). Depression, dissociation, and psychosis assessments were made before and after inhalations. In TRD patients, functional connectivity was reduced in all seeded networks and the voxel-wise global analysis after N2O exposure. N2O progressively decreased connectivity in patients with TRD but increased connectivity in healthy controls. In TRD patients, each seeded network demonstrated post-inhalation functional connectivity reductions in the dorsal paracingulate gyrus ("dorsal nexus"). This study further elucidates neural mechanisms underlying the antidepressant properties of N2O, supporting the notion that N2O specifically alters mood-associated brain regions in the depressed brain state by reducing functional connectivity within these brain networks. The trial was registered at ClinicalTrials.gov (NCT02994433).

15.
Neuroimage ; 71: 19-29, 2013 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-23313780

RESUMO

In aeronautics, plan continuation error (PCE) represents failure to revise a flight plan despite emerging evidence suggesting that it is no longer safe. Assuming that PCE may be associated with a shift from cold to hot reasoning, we hypothesized that this transition may result from a large range of strong negative emotional influences linked with the decision to abort a landing and circle for a repeat attempt, referred to as a "go-around". We investigated this hypothesis by combining functional neuroimaging with an ecologically valid aviation task performed under contextual variation in incentive and situational uncertainty. Our goal was to identify regional brain activity related to the sorts of conservative or liberal decision-making strategies engaged when participants were both exposed to a financial payoff matrix constructed to bias responses in favor of landing acceptance, while they were simultaneously experiencing maximum levels of uncertainty related to high levels of stimulus ambiguity. Combined with the observed behavioral outcomes, our neuroimaging results revealed a shift from cold to hot decision making in response to high uncertainty when participants were exposed to the financial incentive. Most notably, while we observed activity increases in response to uncertainty in many frontal regions such as dorsolateral prefrontal cortex (DLPFC) and anterior cingulate cortex (ACC), less overall activity was observed when the reward was combined with uncertainty. Moreover, participants with poor decision making, quantified as a lower discriminability index d', exhibited riskier behavior coupled with lower activity in the right DLPFC. These outcomes suggest a disruptive effect of biased financial incentive and high uncertainty on the rational decision-making neural network, and consequently, on decision relevance.


Assuntos
Aviação , Encéfalo/fisiologia , Tomada de Decisões/fisiologia , Incerteza , Adulto , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Desempenho Psicomotor/fisiologia
16.
J Affect Disord ; 339: 717-724, 2023 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-37437742

RESUMO

BACKGROUND: Depression is one of the most concerning mental disorders in youth. Because atypical excessive neural activity during self-referential processing is often implicated in depression, identifying psychological factors that link to lower depression and less excessive neural activity during self-referential processing is critical for treatment development. This study examined the relationship between self-compassion - a protective factor of youth depression - and neural activity during self-appraisals, a well-established experimental paradigm for studying self-referential processing, and their associations with depression severity in depressed and healthy youth. METHODS: The sample consisted of 115 youth (79 met the clinical diagnosis of depression; 36 were matched healthy controls) aged from 11 to 17 years (68 females). Self-compassion and depression severity were measured with self-reported scales. In the scanner, participants were asked to judge whether the phrases they heard described them from four perspectives (self, mother, classmate, and best friend). RESULTS: Higher self-compassion was associated with lower PCC/precuneus activity especially during negatively-valenced self-appraisals and explained its association with reduced depression severity. In depressed youth, higher self-compassion was associated with lower superior temporal gyrus/operculum/postcentral gyrus/insula activity especially during positively-valenced self-appraisals. In healthy youth, higher self-compassion was associated with higher activity in these regions. CONCLUSIONS: Self-compassion was associated with less excessive experiential immersion and/or autobiographical memory retrieval during negative self-appraisals. Neural stimulation interventions targeting PCC/precuneus activity during negative self-appraisals combined with behavioral interventions targeting self-compassion could be a promising approach to youth depression treatment.


Assuntos
Autoavaliação Diagnóstica , Autocompaixão , Feminino , Humanos , Adolescente , Mães , Lobo Parietal , Autorrelato , Depressão/psicologia , Empatia
17.
Biol Psychiatry Glob Open Sci ; 3(4): 698-704, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37881568

RESUMO

Background: Nitrous oxide holds promise in the treatment of major depressive disorder. Its psychotropic effects and NMDA receptor antagonism have led to comparisons with ketamine. Despite longstanding use, persistent effects of nitrous oxide on the brain have not been characterized. Methods: Sixteen healthy volunteers were recruited in a double-blind crossover study. In randomized order, individuals underwent a 1-hour inhalation of either 50% nitrous oxide/oxygen or air/oxygen mixtures. At least two 7.5-minute echo-planar resting-state functional magnetic resonance imaging scans were obtained before and at 2 and 24 hours after each inhalation (average 130 min/participant). Using the time series of preprocessed, motion artifact-scrubbed, and nuisance covariate-regressed imaging data, interregional signal correlations were measured and converted to T scores. Hierarchical clustering and linear mixed-effects models were employed. Results: Nitrous oxide inhalation produced changes in global brain connectivity that persisted in the occipital cortex at 2 and 24 hours postinhalation (p < .05, false discovery rate-corrected). Analysis of resting-state networks demonstrated robust strengthening of connectivity between regions of the visual network and those of the dorsal attention network, across 2 and 24 hours after inhalation (p < .05, false discovery rate-corrected). Weaker changes in connectivity were found between the visual cortex and regions of the frontoparietal and default mode networks. Parallel analyses following air/oxygen inhalation yielded no significant changes in functional connectivity. Conclusions: Nitrous oxide inhalation in healthy volunteers revealed persistent increases in global connectivity between regions of primary visual cortex and dorsal attention network. These findings suggest that nitrous oxide inhalation induces neurophysiological cortical changes that persist for at least 24 hours.

18.
Hum Brain Mapp ; 33(7): 1553-81, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21465627

RESUMO

Autistics often exhibit enhanced perceptual abilities when engaged in visual search, visual discrimination, and embedded figure detection. In similar fashion, while performing a range of perceptual or cognitive tasks, autistics display stronger physiological engagement of the visual system than do non-autistics. To account for these findings, the Enhanced Perceptual Functioning Model proposes that enhanced autistic performance in basic perceptual tasks results from stronger engagement of sensory processing mechanisms, a situation that may facilitate an atypically prominent role for perceptual mechanisms in supporting cognition. Using quantitative meta-analysis of published functional imaging studies from which Activation Likelihood Estimation maps were computed, we asked whether autism is associated with enhanced task-related activity for a broad range of visual tasks. To determine whether atypical engagement of visual processing is a general or domain-specific phenomenon, we examined three different visual processing domains: faces, objects, and words. Overall, we observed more activity in autistics compared to non-autistics in temporal, occipital, and parietal regions. In contrast, autistics exhibited less activity in frontal cortex. The spatial distribution of the observed differential between-group patterns varied across processing domains. Autism may be characterized by enhanced functional resource allocation in regions associated with visual processing and expertise. Atypical adult organizational patterns may reflect underlying differences in developmental neural plasticity that can result in aspects of the autistic phenotype, including enhanced visual skills, atypical face processing, and hyperlexia.


Assuntos
Transtorno Autístico/fisiopatologia , Encéfalo/fisiologia , Percepção Visual/fisiologia , Mapeamento Encefálico/métodos , Humanos , Modelos Neurológicos , Estimulação Luminosa/métodos
19.
Hum Brain Mapp ; 33(12): 2815-30, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21954026

RESUMO

Physiological noise arising from a variety of sources can significantly degrade the detection of task-related activity in BOLD-contrast fMRI experiments. If whole head spatial coverage is desired, effective suppression of oscillatory physiological noise from cardiac and respiratory fluctuations is quite difficult without external monitoring, since traditional EPI acquisition methods cannot sample the signal rapidly enough to satisfy the Nyquist sampling theorem, leading to temporal aliasing of noise. Using a combination of high speed magnetic resonance inverse imaging (InI) and digital filtering, we demonstrate that it is possible to suppress cardiac and respiratory noise without auxiliary monitoring, while achieving whole head spatial coverage and reasonable spatial resolution. Our systematic study of the effects of different moving average (MA) digital filters demonstrates that a MA filter with a 2 s window can effectively reduce the variance in the hemodynamic baseline signal, thereby achieving 57%-58% improvements in peak z-statistic values compared to unfiltered InI or spatially smoothed EPI data (FWHM = 8.6 mm). In conclusion, the high temporal sampling rates achievable with InI permit significant reductions in physiological noise using standard temporal filtering techniques that result in significant improvements in hemodynamic response estimation.


Assuntos
Encéfalo/fisiologia , Neuroimagem Funcional/métodos , Processamento de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Adulto , Artefatos , Simulação por Computador , Humanos
20.
medRxiv ; 2022 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-36172134

RESUMO

Background: Recovery after SARS-CoV-2 infection is extremely variable, with some individuals recovering quickly, and others experiencing persistent long-term symptoms or developing new symptoms after the acute phase of infection, including fatigue, poor concentration, impaired attention, or memory deficits. Many existing studies reporting cognitive deficits associated with SARS-CoV-2 infection are limited by the exclusive use of self-reported measures or a lack of adequate comparison groups. Methods: Forty-five participants, ages 18-70, (11 Long-COVID, 14 COVID, and 20 No-COVID) underwent behavioral testing with the NIH Toolbox Neuro-Quality of Life survey and selected psychometric tests, including a flanker interference task and the d2 Test of Attention. Results: We found greater self-reported anxiety, apathy, fatigue, emotional dyscontrol, sleep disturbance and cognitive dysfunction in COVID compared No-COVID groups. After categorizing COVID patients according to self-reported concentration problems, we observed declining performance patterns in multiple attention measures across No-COVID controls, COVID and Long-COVID groups. COVID participants, compared to No-COVID controls, exhibited worse performance on NIH Toolbox assessments, including the Eriksen Flanker, Nine-Hole Pegboard and Auditory Verbal Learning tests. Conclusion: This study provides convergent evidence that previous SARS-CoV-2 infection is associated with impairments in sustained attention, processing speed, self-reported fatigue and concentration. The finding that some patients have cognitive and visuomotor dysfunction in the absence of self-reported problems suggests that SARS-CoV-2 infection can have unexpected and persistent subclinical consequences.

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