Parameter Space and Potential for Biomarker Development in 25 Years of fMRI Drug Cue Reactivity: A Systematic Review

Importance

In the last 25 years, functional magnetic resonance imaging drug cue reactivity (FDCR) studies have characterized some core aspects in the neurobiology of drug addiction. However, no FDCR-derived biomarkers have been approved for treatment development or clinical adoption. Traversing this translational gap requires a systematic assessment of the FDCR literature evidence, its heterogeneity, and an evaluation of possible clinical uses of FDCR-derived biomarkers.

Objective

To summarize the state of the field of FDCR, assess their potential for biomarker development, and outline a clear process for biomarker qualification to guide future research and validation efforts.

Evidence Review

The PubMed and Medline databases were searched for every original FDCR investigation published from database inception until December 2022. Collected data covered study design, participant characteristics, FDCR task design, and whether each study provided evidence that might potentially help develop susceptibility, diagnostic, response, prognostic, predictive, or severity biomarkers for 1 or more addictive disorders.

Findings

There were 415 FDCR studies published between 1998 and 2022. Most focused on nicotine (122 [29.6%]), alcohol (120 [29.2%]), or cocaine (46 [11.1%]), and most used visual cues (354 [85.3%]). Together, these studies recruited 19 311 participants, including 13 812 individuals with past or current substance use disorders. Most studies could potentially support biomarker development, including diagnostic (143 [32.7%]), treatment response (141 [32.3%]), severity (84 [19.2%]), prognostic (30 [6.9%]), predictive (25 [5.7%]), monitoring (12 [2.7%]), and susceptibility (2 [0.5%]) biomarkers. A total of 155 interventional studies used FDCR, mostly to investigate pharmacological (67 [43.2%]) or cognitive/behavioral (51 [32.9%]) interventions; 141 studies used FDCR as a response measure, of which 125 (88.7%) reported significant interventional FDCR alterations; and 25 studies used FDCR as an intervention outcome predictor, with 24 (96%) finding significant associations between FDCR markers and treatment outcomes.

Conclusions and Relevance

Based on this systematic review and the proposed biomarker development framework, there is a pathway for the development and regulatory qualification of FDCR-based biomarkers of addiction and recovery. Further validation could support the use of FDCR-derived measures, potentially accelerating treatment development and improving diagnostic, prognostic, and predictive clinical judgments.

Attentional biases for sad faces in offspring of mothers with a history of major depression: trajectories of change from childhood to adolescence

BACKGROUND

Theorists have proposed that the way children process social-emotional information may serve as a mechanism of risk for the intergenerational transmission of depression. There is growing evidence that infants and children of mothers with a history of major depressive disorder (MDD) during the child's life exhibit attentional avoidance of sad faces, which has been proposed as an early emerging emotion regulation strategy. In contrast, there is clear evidence that at-risk and depressed adolescents and adults exhibit difficulty disengaging attention from sad faces.

METHODS

Seeking to link these two literatures, the current U.S.-based study used eye tracking within the context of an accelerated longitudinal design to assess attentional biases in 8-14-year-old offspring of mothers with a history MDD during the child's life (n = 123) or no history of MDD (n = 119) every six months for two years, allowing us to map trajectories of attention from age 8 to 16.

RESULTS

Mother MDD history moderated age-based changes in children's gaze duration to sad (t[240] = 2.44, p = .02), but not happy (t[240] = 0.11, p = .91) or angry (t[240] = 0.67, p = .50), faces. Consistent our hypotheses, offspring of mothers with MDD exhibited significantly less attention to sad faces than offspring of never depressed mothers before age 8.5 but significantly more attention to sad faces after age 14.5, which was due to an increase in gaze duration to sad faces from childhood to adolescence among offspring of mothers with MDD (t[122] = 5.44, p < .001) but not among offspring of never depressed mothers (t[118] = 1.49, p = .14).

CONCLUSIONS

It appears that the form, and perhaps function, of attentional bias may shift across development in at-risk youth. To the extent that this is true, it has significant implications not only for theories of the intergenerational transmission of depression risk but also for prevention and early intervention efforts designed to reduce this risk.

Attentional capture by angry faces in girls who self-injure: Evidence from steady state visual evoked potentials

BACKGROUND

Non-suicidal self-injury (NSSI) is a significant public health concern, not only because of the personal and social cost of the behavior itself, but also because it increases risk for future self-injurious behaviors, including suicide attempts. NSSI is increasingly prevalent during adolescence, which highlights the need for research aimed at identifying modifiable risk factors that can be targeted to reduce future risk. Building from theoretical models that highlight interpersonal processes, this study examined whether adolescents with an NSSI history exhibit greater difficulty inhibiting attention to emotionally salient interpersonal stimuli (face), indexed via steady state visual evoked potentials (SSVEPs), which provide a direct neural index of the ability to inhibit attention to task-irrelevant stimuli.

METHODS

Adolescent girls aged 13-17 with (n = 26) and without (n = 28) an NSSI history completed a change-detection computer task during which frequency-tagged SSVEPs were used to assess adolescents' ability to inhibit attention to affectively salient stimuli from spatially superimposed targets.

RESULTS

Compared with adolescents with no NSSI history, adolescents with NSSI demonstrated difficulty inhibiting attention to angry adult faces.

CONCLUSIONS

These findings underscore specific deficits in attentional filtering among girls with an NSSI history, which, if replicated and extended, could be a promising intervention target for reducing risk for future NSSI.

Low-to-moderate level of perceived stress strengthens working memory: Testing the hormesis hypothesis through neural activation

The negative impact of stress on neurocognitive functioning is extensively documented by empirical research. However, emerging reports suggest that stress may also confer positive neurocognitive effects. This hypothesis has been advanced by the hormesis model of psychosocial stress, in which low-moderate levels of stress are expected to result in neurocognitive benefits, such as improved working memory (WM), a central executive function. We tested the hormesis hypothesis, purporting an inverted U-shaped relation between stress and neurocognitive performance, in a large sample of young adults from the Human Connectome Project (n = 1000, Mage = 28.74, SD = 3.67, 54.3% female). In particular, we investigated whether neural response during a WM challenge is a potential intermediary through which low-moderate levels of stress confer beneficial effects on WM performance. Further, we tested whether the association between low-moderate prolonged stress and WM-related neural function was stronger in contexts with more psychosocial resources. Findings showed that low-moderate levels of perceived stress were associated with elevated WM-related neural activation, resulting in more optimal WM behavioral performance (α *β = -0.02, p = .046). The strength of this association tapered off at high-stress levels. Finally, we found that the benefit of low-moderate stress was stronger among individuals with access to higher levels of psychosocial resources (β = -0.06, p = .021). By drawing attention to the dose-dependent, nonlinear relation between stress and WM, this study highlights emerging evidence of a process by which mild stress induces neurocognitive benefits, and the psychosocial context under which benefits are most likely to manifest.

Neuroanatomical foundations of delayed reward discounting decision making II: Evaluation of sulcal morphology and fractal dimensionality

Delayed reward discounting (DRD) is a form of decision-making reflecting valuation of smaller immediate rewards versus larger delayed rewards, and high DRD has been linked to several health behaviors, including substance use disorders, attention-deficit/hyperactivity disorder, and obesity. Elucidating the underlying neuroanatomical factors may offer important insights into the etiology of these conditions. We used structural MRI scans of 1038 Human Connectome Project participants (M_age = 28.86, 54.7% female) to explore two novel measures of neuroanatomy related to DRD: 1) sulcal morphology (SM; depth and width) and 2) fractal dimensionality (FD), or cortical morphometric complexity, of parcellated cortical and subcortical regions. To ascertain unique contributions to DRD preferences, indicators that displayed significant partial correlations with DRD after family-wise error correction were entered into iterative mixed-effect models guided by the association magnitude. When considering only SM indicators, the depth of the right inferior and width of the left central sulci were uniquely associated with DRD preferences. When considering only FD indicators, the FD of the left middle temporal gyrus, right lateral orbitofrontal cortex, and left lateral occipital and entorhinal cortices uniquely contributed DRD. When considering SM and FD indicators simultaneously, the right inferior frontal sulcus depth and left central sulcus width; and the FD of the left middle temporal gyrus, lateral occipital cortex and entorhinal cortex were uniquely associated with DRD. These results implicate SM and FD as features of the brain that underlie variation in the DRD decision-making phenotype and as promising candidates for understanding DRD as a biobehavioral disease process.

Age differences in neural response to reward and loss in children

The goal of this study was to examine age-related differences in children's reward processing. Focusing on reward outcome processing, we used event-related potentials to examine substages of neural response to gain versus loss feedback in a sample of 7-11-year-old children (M = 9.67, SD = 1.40) recruited from the community (N = 234; 47.6% girls, 66.2% non-Hispanic European American). Using principal components analysis (PCA), we focused on temporospatial combinations that closely resembled the RewP, fb-P3, and fb-LPP in temporal and spatial distributions. Two of these, the PCA factors reflecting the RewP and fb-LPP, demonstrated age-related differences in response to gains versus losses. Age-related changes in the RewP were specific to gain feedback, with RewP amplitudes to gain, but not loss, increasing from middle to late childhood. In contrast, age-related changes in fb-LPP were specific to loss feedback, with fb-LPP amplitudes to losses, but not gains, decreasing from middle to late childhood. Follow-up analyses revealed that children younger than age 8 exhibited larger fb-LPP responses to loss than gain, whereas children older than age 10 exhibited larger RewP responses to gain than loss. Similar results were obtained using mean amplitude-based ERP indices and the results do not appear to have been due to age-related differences in the latency or location of the ERPs themselves. These results highlight the importance of examining distinct substages of reward outcome processing and suggest that robust neural responses to loss feedback may emerge earlier in childhood than responses to gains.

Maternal criticism and children's neural responses to reward and loss

Parental criticism is linked to a number of detrimental child outcomes. One mechanism by which parental criticism may increase risk for negative outcomes in children is through children's neural responses to valenced information in the environment. The goal of the current study, therefore, was to examine the relation between maternal criticism and children's neural responses to monetary gains and losses. To represent daily environmental experiences of reward and punishment, we focused on reactivity to monetary gains versus losses in a guessing task. Participants were 202 children and their mothers recruited from the community. The average age of the children was 9.71 years (SD = 1.38, range = 7-11), with 52.0% of them male and 72.8% Caucasian. Mothers completed the Five Minute Speech Sample to assess expressed emotion-criticism, and of these dyads 51 mothers were rated as highly critical. In addition, children completed a simple guessing game during which electroencephalography was recorded. Children of critical mothers displayed less neural reactivity to both monetary gain and loss than children without critical mothers. Our results were at least partially independent of children's and mothers' current levels of internalizing psychopathology. These findings suggest that children exposed to maternal criticism may exhibit disruptions in adaptive responses to environmental experiences regardless of valence. Targeted interventions aimed at reducing expressed emotion-criticism may lead to changes in a child's reward responsiveness and risk for psychopathology.

Brain Predictability toolbox: a Python library for neuroimaging-based machine learning

SUMMARY

Brain Predictability toolbox (BPt) represents a unified framework of machine learning (ML) tools designed to work with both tabulated data (e.g. brain derived, psychiatric, behavioral and physiological variables) and neuroimaging specific data (e.g. brain volumes and surfaces). This package is suitable for investigating a wide range of different neuroimaging-based ML questions, in particular, those queried from large human datasets.

AVAILABILITY AND IMPLEMENTATION

BPt has been developed as an open-source Python 3.6+ package hosted at https://github.com/sahahn/BPt under MIT License, with documentation provided at https://bpt.readthedocs.io/en/latest/, and continues to be actively developed. The project can be downloaded through the github link provided. A web GUI interface based on the same code is currently under development and can be set up through docker with instructions at https://github.com/sahahn/BPt_app.

Multimodal brain predictors of current weight and weight gain in children enrolled in the ABCD study ®

Multimodal neuroimaging assessments were utilized to identify generalizable brain correlates of current body mass index (BMI) and predictors of pathological weight gain (i.e., beyond normative development) one year later. Multimodal data from children enrolled in the Adolescent Brain Cognitive Development Study® at 9-to-10-years-old, consisted of structural magnetic resonance imaging (MRI), diffusion tensor imaging (DTI), resting state (rs), and three task-based functional (f) MRI scans assessing reward processing, inhibitory control, and working memory. Cross-validated elastic-net regression revealed widespread structural associations with BMI (e.g., cortical thickness, surface area, subcortical volume, and DTI), which explained 35% of the variance in the training set and generalized well to the test set (R2 = 0.27). Widespread rsfMRI inter- and intra-network correlations were related to BMI (R2train = 0.21; R2test = 0.14), as were regional activations on the working memory task (R2train = 0.20; (R2test = 0.16). However, reward and inhibitory control tasks were unrelated to BMI. Further, pathological weight gain was predicted by structural features (Area Under the Curve (AUC)train = 0.83; AUCtest = 0.83, p < 0.001), but not by fMRI nor rsfMRI. These results establish generalizable brain correlates of current weight and future pathological weight gain. These results also suggest that sMRI may have particular value for identifying children at risk for pathological weight gain.

Neural correlates of sustained attention and cognitive control in depression and rumination: An ERP study

Attention problems and risk for depression are often associated with a trait tendency towards rumination. Although theorists have linked rumination to deficits in attention, the nature of its effect on cognitive control, and how it may interact with depression remains unclear. Therefore, this study explored cognitive control in depression and two forms of rumination (brooding and reflection) associated with passive and analytic responses to negative mood, respectively. An electrophysiological Go/NoGo vigilance task was used to measure N2 and P3 event related potentials (ERPs) associated with the recruitment of cognitive resources and inhibition of motor responses in the task, respectively. Participants continuous levels of depressive symptoms and trait levels of each form of rumination were also obtained by self-report. Consistent with prior research, significantly larger mean amplitudes in the N2 and P3 ranges were observed in NoGo versus Go trials. A significant interaction between reflection and depression on P3 amplitudes was observed, indicating that at high levels of reflection, as depression increased P3 amplitudes to NoGo trials also increased. Levels of depression and reflection were not significantly associated with accuracy or reaction time in the task. No significant interactions between depression and brooding, or main effect of brooding was observed on any task measure. Thus, high levels of reflection may uniquely and negatively impact the efficiency that cognitive resources are applied during goal directed behavior in depression. Results are discussed in relation to cognitive models of depression and rumination.

Obsessive-Compulsive Disorder in the Adolescent Brain Cognitive Development Study: Impact of Changes From DSM-IV to DSM-5

The Diagnostic and Statistical Manual of Mental Disorders (DSM), used to diagnose psychiatric disorders, was revised to DSM-5 in 2013. Changes were made to the criteria for obsessive-compulsive disorder (OCD), a disorder with a lifetime prevalence of 1% to 3% in children.¹ Prior revisions to OCD criteria (from DSM-III to DSM-IV) resulted in lower reported prevalence rates,² but this is not yet clear with DSM-5. In DSM-5, the definition of obsessions was broadened (Table 1), and the requirement that obsessions cause marked anxiety or distress was removed. Thus we examined rates of OCD within the Adolescent Brain Cognitive Development (ABCD) study³ using both DSM-IV and DSM-5 criteria.

Attentional biases to emotional faces among women with a history of single episode versus recurrent major depression

Major depressive disorder (MDD) is a highly prevalent psychiatric disorder, and recurrent depression is associated with severe and chronic impairment. Identifying markers of risk is imperative to improve our ability to predict which individuals are likely to experience a recurrence. According to cognitive theories, biases in attention for affectively-salient information may serve as one mechanism of risk. Existing research has combined participants with a single episode (sMDD) and those with recurrent MDD (rMDD); therefore, little is known about whether these biases track the severity of disease course. The current study examined attentional biases to facial displays of emotion among 115 women with a history of rMDD, sMDD, or no history of psychopathology using a passive viewing eye-tracking task. Women with rMDD exhibited significantly lower sustained attention to happy faces compared to both healthy controls and sMDD women. These results extend previous research on the presence of attentional avoidance of positive stimuli in individuals with a history of MDD and provide preliminary evidence that this bias is strongest among individuals with a history of rMDD.

Reward Responsiveness in Suicide Attempters: An Electroencephalography/Event-Related Potential Study

BACKGROUND

The present study aimed to objectively examine the Research Domain Criteria (RDoC) subconstructs of reward anticipation and initial response to reward in adult suicide attempters, compared with nonattempters, using electroencephalography (EEG) and event-related potentials (ERPs) within the context of the RDoC-recommended experimental paradigms for these subconstructs.

METHODS

Participants had either a history of at least 1 suicide attempt (n = 30) or no history of attempting suicide (n = 30). They completed diagnostic interviews, self-report questionnaires, and 2 computer-based tasks-the monetary incentive delay task and the doors task-during which continuous EEG was recorded. Temporospatial principal component analysis was used to isolate each of the ERP components of interest from other temporally or spatially overlapping components. Exploratory time-frequency analyses were also conducted to supplement the ERP analyses.

RESULTS

Suicide attempters, compared with nonattempters, exhibited specific deficits in reward anticipation (i.e., blunted cue-P3 ERP during the monetary incentive delay task) and in initial response to reward (i.e., reduced feedback-related delta power in the gain condition of the doors task). These results were at least partially independent of current symptoms or diagnoses of depression and anxiety.

CONCLUSIONS

These findings constitute an important step in obtaining a more fine-grained understanding of the specific reward-related abnormalities that might contribute to suicide risk.

Blunted Neural Reward Responsiveness in Children with Recent Suicidal Ideation

Individuals with suicidal thoughts and behaviors experience abnormalities in reward-related processes, yet little is known about specific components or stages of reward processing that are impaired, especially in children. The primary aim of this study was to conduct an investigation of the Initial Response to Reward subconstruct of the National Institute of Mental Health's Research Domain Criteria in relation to recent suicidal ideation (SI) in children. Participants were 23 children between the ages of 7 and 11 with a history of recent SI and 46 demographically and clinically matched children with no recent SI. Children completed a simple guessing task during which continuous electroencephalography was recorded to isolate the Reward Positivity (ΔRewP) event-related potential, which reflects the difference in neural responses to monetary gains (RewP-gain) versus losses (RewP-loss). Children with recent SI exhibited significantly smaller (i.e., blunted) ΔRewP, providing initial evidence for blunted initial responses to reward in these children.

Delivery or expectant management for prevention of adverse maternal and neonatal outcomes in hypertensive disorders of pregnancy: an individual participant data meta-analysis

OBJECTIVE

Hypertensive disorders affect 3-10% of pregnancies. Delayed delivery carries maternal risks, while early delivery increases fetal risk, so appropriate timing is important. The aim of this study was to compare immediate delivery with expectant management for prevention of adverse maternal and neonatal outcomes in women with hypertensive disease in pregnancy.

METHODS

CENTRAL, PubMed, MEDLINE and ClinicalTrials.gov were searched for randomized controlled trials comparing immediate delivery to expectant management in women presenting with gestational hypertension or pre-eclampsia without severe features from 34 weeks of gestation. The primary neonatal outcome was respiratory distress syndrome (RDS) and the primary maternal outcome was a composite of HELLP syndrome and eclampsia. The PRISMA-IPD guideline was followed and a two-stage meta-analysis approach was used. Relative risks (RR) and numbers needed to treat or harm (NNT/NNH) with 95% CI were calculated to evaluate the effect of the intervention.

RESULTS

Main outcomes were available for 1724 eligible women. Compared with expectant management, immediate delivery reduced the composite risk of HELLP syndrome and eclampsia in all women (0.8% vs 2.8%; RR, 0.33 (95% CI, 0.15-0.73); I2  = 0%; NNT, 51 (95% CI, 31.1-139.3)) as well as in the pre-eclampsia subgroup (1.1% vs 3.5%; RR, 0.39 (95% CI, 0.15-0.98); I2  = 0%). Immediate delivery increased RDS risk (3.4% vs 1.6%; RR, 1.94 (95% CI 1.05-3.6); I2  = 24%; NNH, 58 (95% CI, 31.1-363.1)), but depended upon gestational age. Immediate delivery in the 35th week of gestation increased RDS risk (5.1% vs 0.6%; RR, 5.5 (95% CI, 1.0-29.6); I2  = 0%), but immediate delivery in the 36th week did not (1.5% vs 0.4%; RR, 3.4 (95% CI, 0.4-30.3); I2 not applicable).

CONCLUSION

In women with hypertension in pregnancy, immediate delivery reduces the risk of maternal complications, whilst the effect on the neonate depends on gestational age. Specifically, women with a-priori higher risk of progression to HELLP, such as those already presenting with pre-eclampsia instead of gestational hypertension, were shown to benefit from earlier delivery. © 2019 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of the International Society of Ultrasound in Obstetrics and Gynecology.

Children's sustained attention to emotional facial expressions and their autonomic nervous system reactivity during parent-child interactions

The way individuals process socio-affective information is thought to impact their responses to social interactions, but research testing the relation between these processes is scarce, particularly among children. This study examined if children's attention to socio-affective stimuli was associated with their autonomic nervous system (ANS) reactivity during parent-child interactions. Children's sustained attention to facial expressions of emotion (afraid, happy, sad) was indexed using the late positive potential (LPP) event-related potential (ERP) component during a computer-based task. To measure ANS reactivity, children's respiratory sinus arrhythmia (RSA) was assessed at baseline and during positive and negative parent-child discussions. Enhanced LPP amplitudes in response to all emotional facial expressions, reflecting greater sustained attention to socio-affective stimuli, were associated with increased RSA reactivity during parent-child discussions. These results show correspondence between two psychophysiological substrates of emotion processing in healthy children and highlight how these systems may be synergistic forces contributing to emotion reactivity.

Identical and Nonidentical Twins: Risk and Factors Involved in Development of Islet Autoimmunity and Type 1 Diabetes

OBJECTIVE

There are variable reports of risk of concordance for progression to islet autoantibodies and type 1 diabetes in identical twins after one twin is diagnosed. We examined development of positive autoantibodies and type 1 diabetes and the effects of genetic factors and common environment on autoantibody positivity in identical twins, nonidentical twins, and full siblings.

RESEARCH DESIGN AND METHODS

Subjects from the TrialNet Pathway to Prevention Study (N = 48,026) were screened from 2004 to 2015 for islet autoantibodies (GAD antibody [GADA], insulinoma-associated antigen 2 [IA-2A], and autoantibodies against insulin [IAA]). Of these subjects, 17,226 (157 identical twins, 283 nonidentical twins, and 16,786 full siblings) were followed for autoantibody positivity or type 1 diabetes for a median of 2.1 years.

RESULTS

At screening, identical twins were more likely to have positive GADA, IA-2A, and IAA than nonidentical twins or full siblings (all P < 0.0001). Younger age, male sex, and genetic factors were significant factors for expression of IA-2A, IAA, one or more positive autoantibodies, and two or more positive autoantibodies (all P ≤ 0.03). Initially autoantibody-positive identical twins had a 69% risk of diabetes by 3 years compared with 1.5% for initially autoantibody-negative identical twins. In nonidentical twins, type 1 diabetes risk by 3 years was 72% for initially multiple autoantibody-positive, 13% for single autoantibody-positive, and 0% for initially autoantibody-negative nonidentical twins. Full siblings had a 3-year type 1 diabetes risk of 47% for multiple autoantibody-positive, 12% for single autoantibody-positive, and 0.5% for initially autoantibody-negative subjects.

CONCLUSIONS

Risk of type 1 diabetes at 3 years is high for initially multiple and single autoantibody-positive identical twins and multiple autoantibody-positive nonidentical twins. Genetic predisposition, age, and male sex are significant risk factors for development of positive autoantibodies in twins.

Lagged effects of substance use on PTSD severity in a randomized controlled trial with modified prolonged exposure and relapse prevention

OBJECTIVE

To advance understanding of the effectiveness of evidence-based treatments for comorbid posttraumatic stress disorder (PTSD) and substance use disorder (SUD), research must provide a more nuanced picture of how substance use affects change in PTSD symptoms over the course of treatments and whether prolonged exposure techniques can be efficacious during active substance use. A data set that included patients with PTSD/subthreshold-PTSD and SUD treated with an exposure-based intervention provided an opportunity to conduct a secondary analysis to test how patients' substance use impacted PTSD change over treatment.

METHOD

We applied growth models to week-to-week PTSD symptom and substance use changes during treatment and follow-up of a randomized controlled trial of two cognitive-behavioral treatments for PTSD and SUD: Concurrent Treatment of PTSD and SUD Using Prolonged Exposure (COPE) and Relapse Prevention Therapy (RPT). Cross-lagged analyses were used to determine whether prior week substance use impacted subsequent PTSD symptom severity.

RESULTS

Both treatments evidenced significant reductions in PTSD symptom severity. In the context of continued substance use, results suggest that individuals still benefit from exposure-based treatment.

CONCLUSION

Results provide evidence that RPT and COPE both led to significant reductions in PTSD, providing further support that exposure-based techniques tailored for SUD can be conducted without jeopardizing PTSD or SUD outcomes. Implications for clinical decision making around treatment selection are discussed. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Neural reward responsiveness in children who engage in nonsuicidal self-injury: an ERP study

BACKGROUND

A better understanding of the correlates of nonsuicidal self-injury (NSSI) in children is important for the identification and prevention of future suicide risk. However, although abnormalities in reward responsiveness might constitute one potential transdiagnostic mechanism of risk for NSSI, no studies have examined initial response to reward in children with a history of NSSI. The goal of the present study was to address this important gap in the literature. To objectively assess initial response to reward, we utilized the feedback negativity (FN) event-related potential, a well-established psychophysiological marker of reward responsiveness.

METHODS

Participants were 57 children (19 with a history of NSSI and 38 demographically matched controls) between the ages of 7 and 11. Diagnostic interviews were used to assess for current and past DSM-IV mood and anxiety diagnoses and NSSI history. Children also completed a guessing task, during which continuous electroencephalography was recorded.

RESULTS

Children with a history of NSSI exhibited significantly more negative ΔFN (i.e., FN to losses minus FN to gains) than children without NSSI. These findings appeared to be at least partially independent of children's history of psychopathology and current symptoms, suggesting their specificity to NSSI.

CONCLUSIONS

These results provide initial evidence for heightened neural initial reward responsiveness to losses versus rewards in children with a history of NSSI. Pending replications and longitudinal studies, the ΔFN might represent a psychophysiological marker of risk for self-harm.

Peer influence, Frontostriatal connectivity, and delay discounting in African American emerging adults

Prior research has demonstrated the importance of delay discounting in adverse health behaviors, such as addiction, attention deficit hyperactivity disorder, risk taking, and obesity. Nevertheless, the functional connectivity of neural circuitry associated with delay discounting and the ways in which the social environment may influence frontostriatal connectivity remain largely unknown, particularly in African Americans. Building on recent literature implicating frontostriatal connectivity during active delay discounting decision making and at rest, we used functional magnetic resonance imaging to assess the association between delay discounting and frontostriatal resting state connectivity (rsFC). We also examined the capacity of social relationships with parents and peers to longitudinally predict frontostriatal rsFC. The study cohort was composed of 91 rural African American emerging adults followed over a 6-year period. Greater (i.e., more positive) frontostriatal rsFC was associated with decreased delay discounting (i.e., less impulsive decision making). In addition, peer relationships at ages 20 and 21 significantly predicted frontostriatal rsFC at age 25 above and beyond parental influence. A significant indirect effect of peer affiliation on delay discounting through frontostriatal rsFC also emerged. These results indicate a role of frontostriatal connectivity in delay discounting decision making and highlight peers' unique influence on decision making behaviors through frontostriatal rsFC during emerging adulthood.

Participatory action research into implementing open access in musculoskeletal X-ray: Management and staff perspectives

INTRODUCTION

Neighbouring Trusts have implemented open access (walk-in) services to shorten waiting times in x-ray. Despite this, staff perceptions of their effectiveness have not yet been studied. This study forms the initial baseline evaluation phase of wider participatory action research investigating the implementation of an open access service for general practitioner musculoskeletal x-ray referrals. Staff perceptions regarding effectiveness of the current service were gathered, including their opinions regarding the effectiveness of open access services.

METHODS

Qualitative data were obtained via three semi-structured interviews with radiology management and two (cross-site) staff focus groups over a 2 month period. Template analysis was used to interpret the data with the aid of NVIVO 11 to facilitate analysis.

RESULTS

Template analysis uncovered several drivers for changing the current service including waiting times, external pressures, patient choice and administrative delays. 'Flexibility' was the key theme to arise during discussion regarding the effectiveness of the current service. Potential for improved access was highlighted as a major benefit to the implementation of open access, however 'workload', 'staffing' and 'communication' were all identified as potential barriers to its implementation.

CONCLUSION

Although several staff members were satisfied with current service several drivers for change were identified that need to be addressed in order to truly deliver a service that fulfils the patients' needs. Results will inform the wider participatory action research that will investigate the barriers to implementing an open access service and identify whether this is indeed a suitable method of addressing the drivers for change.

Parental Expressed Emotion-Criticism and Neural Markers of Sustained Attention to Emotional Faces in Children

There is growing evidence for the role of environmental influences on children's information-processing biases for affectively salient stimuli. The goal of this study was to extend this research by examining the relation between parental criticism (expressed emotion-criticism, or EE-Crit) and children's processing of facial displays of emotion. Specifically, we examined the relation between EE-Crit and children's sensitivity in detecting facial displays of emotion. We also examined a neural marker of sustained attention, the late positive potential (LPP) event-related potential component (ERP). Participants were 87 children (ages 7-11 years; 53.3% female, 77.8% Caucasian) and their parents (ages 24-71; 90% female, 88.9% Caucasian). Parents completed the Five-Minute Speech Sample to determine levels of EE-Crit toward their child. Children completed a morphed faces task during which behavioral and ERP responses were assessed. Although there were no group differences in sensitivity in detecting facial displays of emotion, we found that children of parents exhibiting high, compared to low, EE-Crit displayed less attention (smaller LPP magnitudes) to all facial displays of emotion (fearful, happy, sad). These results suggest that children of critical parents may exhibit an avoidant pattern of attention to affectively-salient interpersonal stimuli.

Increased neural and pupillary reactivity to emotional faces in adolescents with current and remitted major depressive disorder

This study combined multiple levels of analysis to examine whether disrupted neural and pupillary reactivity to emotional faces serves as a state- or trait-like marker of adolescent major depressive disorder (MDD). The study examined differences in pupil dilation and the event-related potential (ERP) late positive potential (LPP) component to emotional faces before and after a negative mood induction between 71 adolescents (age 11–18 years) with (i) a current diagnosis of MDD, (ii) a past episode of MDD currently in full remission and (iii) no lifetime history of any Axis I disorder. Relative to healthy control (HC) youth, adolescents with current or remitted MDD exhibited an enhanced LPP and pupillary response to all emotional facial expressions (fearful, happy and sad). This difference in reactivity between remitted depressed and HC adolescents persisted following the negative mood induction. Results also revealed that LPP and pupillary responses to emotional faces were significantly related, but only among the currently depressed adolescents. This study suggests that increased physiological and neural activation in response to social-emotional stimuli may not only characterize currently depressed adolescents, but also remains following MDD remission, potentially serving as a mechanism of risk for future depression relapse.

Suicidal ideation and attentional biases in children: An eye-tracking study

BACKGROUND

Despite theoretical and empirical evidence for a heighted responsiveness to signals of social-threat in suicidal individuals, no studies to date have examined whether this responsiveness might also manifest in the form of specific biases in attention to interpersonal stimuli. The current study, therefore, examined the presence and nature of attentional biases for facial expressions of emotion in children with and without a history of suicidal ideation (SI).

METHOD

Participants were 88 children (44 with a history of SI and 44 demographically and clinically matched controls without such history) recruited from the community. The average age of children was 9.26 years (44.3% female; 67.0% Caucasian). Children's history of SI was assessed via structured interviews with children and their parent. Attentional biases were assessed using a dot probe task and included fearful, happy, and sad facial stimuli and focused on eye tracking and reaction time indices of attentional bias.

RESULTS

Children with a history of SI exhibited significantly greater gaze duration toward fearful faces. The findings appeared to be at least partially independent of children's history of major depression or anxiety disorders or their current depressive or anxious symptoms.

LIMITATIONS

The study is limited by its cross-sectional design, which precludes any causal conclusions regarding the role of attentional biases in future suicide risk.

CONCLUSIONS

Our results suggest that children with a history of SI exhibit biases in sustained attention toward socially-threatening facial expressions. Pending replications, these findings might represent a new avenue of suicide risk assessment and intervention.

Competition Effects in Visual Cortex Between Emotional Distractors and a Primary Task in Remitted Depression

BACKGROUND

Attentional biases, particularly difficulty inhibiting attention to negative stimuli, are implicated in risk for major depressive disorder (MDD). The current study examined a neural measure of attentional bias using a continuous index of visuocortical engagement (steady-state visual evoked potentials [SSVEPs]) before and after a negative mood induction in a population at high-risk for MDD recurrence due to a recently remitted MDD (rMDD) episode. Additionally, we examined working memory (WM) capacity as a potential moderator of the link between rMDD and visuocortical responses.

METHODS

Our sample consisted of 27 women with rMDD and 28 never-depressed women. To assess attentional inhibition to emotional stimuli, we measured frequency-tagged SSVEPs evoked from spatially superimposed task-relevant stimuli and emotional distractors (facial displays of emotion) oscillating at distinct frequencies. WM capacity was assessed during a visuospatial memory task.

RESULTS

Women with rMDD, relative to never-depressed women, displayed difficulty inhibiting attention to all emotional distractors before a negative mood induction, with the strongest effect for negative distractors (sad faces). Following the mood induction, rMDD women's attention to emotional distractors remained largely unchanged. Among women with rMDD, lower WM capacity predicted greater difficulty inhibiting attention to negative and neutral distractors.

CONCLUSIONS

By exploiting the phenomenon of oscillatory resonance in the visual cortex, we tracked competition in neural responses for spatially superimposed stimuli differing in valence. Results demonstrated that women with rMDD display impaired attentional inhibition of emotional distractors independent of state mood and that this bias is strongest among those with lower WM capacity.

Neural responses to gains and losses in children of suicide attempters

[Correction Notice: An Erratum for this article was reported in Vol 126(2) of Journal of Abnormal Psychology (see record 2016-56318-001). In the article, Figure 1 had incorrect axis labels. There was also an error in the abstract, which did not state that ΔFN was calculated as FN to losses minus FN to gains. All versions of this article have been corrected.] Suicidal behavior aggregates within families, yet the specific mechanisms of suicide-risk transmission are poorly understood. Despite some evidence that abnormal patterns of reward responsiveness might constitute one such potential mechanism, empirical evidence is lacking. The goal of this study was to examine neural responses to gains and losses in children of suicide attempters with no personal history of suicide attempt (SA) themselves. To objectively assess these neural responses, we used feedback negativity (FN), a psychophysiological marker of responsiveness to reward and loss. Participants were 66 parents and their 7-11-year-old children (22 with parental history of SA and 44 demographically and clinically matched children of parents with no SA history). Diagnostic interviews were used to gather information about psychiatric diagnoses, symptoms, and histories of suicidal thoughts and behaviors. Children also completed a guessing task, during which continuous electroencephalography (EEG) was recorded. The FN was scored as the mean amplitude, 275-375 ms, following gain or loss feedback at frontocentral sites (Fz and FCz). Children of suicide attempters exhibited significantly more negative ΔFN (i.e., FN to losses minus FN to gains) than children of parents with no SA history. We found that this difference in ΔFN was due specifically to children of parents with a history of SA exhibiting a stronger response to loss, and no group differences were observed for responses to gains. The results suggest that an increased neural response to loss might represent one of the potential pathways of the familial transmission of suicide risk. (PsycINFO Database Record

Attentional biases in children of depressed mothers: An event-related potential (ERP) study

Although a number of studies have reported that children of depressed, compared to nondepressed, parents exhibit biased attention to sad facial stimuli, the direction of this bias remains unclear; some studies find evidence of preferential attention toward sad faces whereas others find evidence of attention avoidance. In the current study, we used event-related potentials (ERPs) to assess children's attention to emotional stimuli using a spatial cueing task. Across all indices of attention bias (N2pc and sustained posterior contralateral negativity [SPCN] time locked to face onset, P3b time locked to probe onset, reaction times [RTs] to probes), children of mothers with a history of major depressive disorder (MDD) during the child's life exhibited less attention to sad faces than children of never depressed mothers. For two of these indices (SPCN and RTs), the attention biases for the offspring of depressed mothers was not specific to sadness and was observed for all emotional expressions. Group differences in the ERP indices were maintained when controlling for the influence of mothers' and children's current symptoms of depression and anxiety, mothers' history of anxiety disorders, and children's history of MDD and anxiety disorders, suggesting that the results are specific to mothers' history of MDD. (PsycINFO Database Record

Pupillary reactivity to negative stimuli prospectively predicts recurrence of major depressive disorder in women

There is a large body of research supporting the association between disrupted physiological reactivity to negative stimuli and depression. The present study aimed to examine whether physiological reactivity to emotional stimuli, assessed via pupil dilation, served as a biological marker of risk for depression recurrence among individuals who are known to be at a higher risk due to having previous history of depression. Participants were 57 women with a history of major depressive disorder (MDD). Pupil dilation to angry, happy, sad, and neutral faces was recorded. Participants' diagnoses and symptoms were assessed 24 months after the initial assessment. We found that women's pupillary reactivity to negative (sad or angry faces) but not positive stimuli prospectively predicted MDD recurrence. Additionally, we found that both hyper- and hypopupillary reactivity to angry faces predicted risk for MDD recurrence. These findings suggest that disrupted physiological response to negative stimuli indexed via pupillary dilation could serve as a physiological marker of MDD risk, thus presenting clinicians with a convenient and inexpensive method to predict which of the at-risk women are more likely to experience depression recurrence.

Charting moment-to-moment brain signal variability from early to late childhood

Large-scale brain signals exhibit rich intermittent patterning, reflecting the fact that the cortex actively eschews fixed points in favor of itinerant wandering with frequent state transitions. Fluctuations in endogenous cortical activity occur at multiple time scales and index a dynamic repertoire of network states that are continuously explored, even in the absence of external sensory inputs. Here, we quantified such moment-to-moment brain signal variability at rest in a large, cross-sectional sample of children ranging in age from seven to eleven years. Our findings revealed a monotonic rise in the complexity of electroencephalogram (EEG) signals as measured by sample entropy, from the youngest to the oldest age cohort, across a range of time scales and spatial regions. From year to year, the greatest changes in intraindividual brain signal variability were recorded at electrodes covering the anterior cortical zones. These results provide converging evidence concerning the age-dependent expansion of functional cortical network states during a critical developmental period ranging from early to late childhood.

Brooding rumination and attentional biases in currently non-depressed individuals: an eye-tracking study

Both rumination and attentional biases have been proposed as key components of the RDoC Negative Valence Systems construct of Loss. Although theorists have proposed that rumination, particularly brooding rumination, should be associated with increased sustained attention to depression-relevant information, it is not clear whether this link would be observed in a non-depressed sample or whether it is specific to brooding versus reflective rumination. To address these questions, the current study examined the link between brooding rumination and attentional biases in a sample of non-depressed individuals (n = 105). Attentional biases were assessed using eye tracking during a passive viewing task in which participants were presented with 2 × 2 arrays of angry, happy, sad, and neutral faces. In line with predictions, higher levels of brooding rumination were associated with greater sustained attention to sad faces and less sustained attention to happy faces. These results remained significant after controlling for participants' prior history of major depression and current nonclinical level of depressive symptoms, suggesting that the link between brooding rumination and attentional biases is at least partially independent of current or past depression.

Selective Attention toward Angry Faces and Risk for Major Depressive Disorder in Women: Converging Evidence from Retrospective and Prospective Analyses

The current study examined selective attention toward emotional images as a risk factor for major depressive disorder (MDD). Using multiple indices of attention in a dot-probe task (i.e., reaction time [RT] and eye-tracking-based measures) in a retrospective, high-risk design, we found that women with remitted MDD, compared to controls, exhibited greater selective attention toward angry faces across RT and eye-tracking indices and greater attention toward sad faces for RT measures. Second, we followed women with remitted MDD prospectively to determine if the attentional biases retrospectively associated with MDD history would predict MDD recurrence across a two-year follow-up. We found that women who spent a greater proportion of time looking at angry faces during the dot-probe task at the baseline assessment had a significantly shorter time to MDD onset. Taken together, these findings provide converging retrospective and prospective evidence that selective attention toward angry faces may increase risk for MDD recurrence.

Developmental changes in spontaneous electrocortical activity and network organization from early to late childhood

We investigated the development of spontaneous (resting state) cerebral electric fields and their network organization from early to late childhood in a large community sample of children. Critically, we examined electrocortical maturation across one-year windows rather than creating aggregate averages that can miss subtle maturational trends. We implemented several novel methodological approaches including a more fine grained examination of spectral features across multiple electrodes, the use of phase-lagged functional connectivity to control for the confounding effects of volume conduction and applying topological network analyses to weighted cortical adjacency matrices. Overall, there were major decreases in absolute EEG spectral density (particularly in the slow wave range) across cortical lobes as a function of age. Moreover, the peak of the alpha frequency increased with chronological age and there was a redistribution of relative spectral density toward the higher frequency ranges, consistent with much of the previous literature. There were age differences in long range functional brain connectivity, particularly in the alpha frequency band, culminating in the most dense and spatially variable networks in the oldest children. We discovered age-related reductions in characteristic path lengths, modularity and homogeneity of alpha-band cortical networks from early to late childhood. In summary, there is evidence of large scale reorganization in endogenous brain electric fields from early to late childhood, suggesting reduced signal amplitudes in the presence of more functionally integrated and band limited coordination of neuronal activity across the cerebral cortex.

Differences in emotion modulation using cognitive reappraisal in individuals with and without suicidal ideation: An ERP study

Difficulties in emotion regulation have been associated with increased suicidal thoughts and behaviours. The majority of studies have examined self-reported use of emotion regulation strategies. In contrast, the current study focused on a direct measure of individuals' ability to use a specific emotion regulation strategy, cognitive reappraisal, using the late positive potential (LPP), an event-related potential component that reflects attention to emotional stimuli. Specifically, the cognitive reappraisal ability of 33 undergraduate students was assessed via an image-viewing task during which the participants had to passively view, increase or reduce their emotions in response to looking at neutral, positive or dysphoric images. We found that participants with a history of suicidal ideation (SI) had significantly higher LPP when asked to reduce negative emotion in response to dysphoric images, compared to individuals with no history of SI. These findings suggest that difficulties with using cognitive reappraisal, specifically to decrease negative affect, might be linked to suicide risk.

Right anterior insula connectivity is important for cue-induced craving in nicotine-dependent smokers

The insula has been implicated in cue-induced craving and relapse in nicotine-dependent tobacco cigarette smokers. The aims of the present study were to identify brain regions that exhibit greater functional connectivity with the right anterior insula in response to smoking cues than to neutral cues and the role of functional connectivity between these regions in mediating cue-induced craving in healthy (free of axis I psychiatric disorders) nicotine-dependent tobacco cigarette smokers. Functional magnetic resonance imaging data were collected from 63 healthy nicotine-dependent smokers viewing blocks of smoking and neutral cues. Craving ratings were obtained after each block. A psychophysiologic interaction approach was used to identify regions that exhibited significantly greater functional connectivity with the right anterior insula (seed) during the smoking cues than during the neutral (corrected cluster thresholding, Z > 2.3, P = 0.05). Parameter estimates of the interaction effects from each region were regressed against the mean cue-induced craving scores. Significant task by seed interactions were observed in two clusters centered in the bilateral precuneus and left angular gyrus. The strength of connectivity between the right anterior insula and the precuneus, which is involved interoceptive processing and self-awareness, was positively correlated with the magnitude of the craving response to the smoking cues (r(2)  = 0.15; P < 0.01). These data suggest that among smokers, cue-induced craving may be a function of connectivity between two regions involved in interoception and self-awareness. Moreover, treatment strategies that incorporate mindful attention may be effective in attenuating cue-induced craving and relapse in nicotine-dependent smokers.

Influence of worry on sustained attention to emotional stimuli: evidence from the late positive potential

There is preliminary evidence to suggest that worry is associated with dysregulated emotion processing resulting from sustained attention to emotional versus neutral stimuli; however, this hypothesis has not been directly tested in prior research. Therefore, the current study used the event-related late positive potential (LPP) to directly examine if high levels of trait worry moderate sustained attention to emotional versus neutral stimuli. Electroencephalogram data was recorded while twenty-two women passively viewed neutral, positive, dysphoric, and threatening emotional images. Consistent with our hypotheses, higher levels of worry were associated with larger LPP amplitudes for emotional images but not neutral images. Importantly, the positive correlations between trait worry and LPP responses to threatening and positive images were maintained even when controlling for the influence of current anxiety symptoms, suggesting that worry may influence emotion processing whether or not the person is currently anxious. This sustained attention to emotional information may be one mechanism underlying how trait worry increases risk for anxiety disorders.

Sensitivity in detecting facial displays of emotion: Impact of maternal depression and oxytocin receptor genotype

The current study examined sensitivity in detecting emotional faces among children of depressed and non-depressed mothers. A second goal was to examine the potential moderating role of the oxytocin receptor gene (OXTR rs53576), which has been linked to emotion recognition in the past. Participants included 247 children (ages 8-14). Children completed a forced choice emotion identification task. Maternal history of major depressive disorder during children's lives was associated with children's sensitivity in detecting emotional faces among children homozygous for the OXTR rs53576 G allele, but not among carriers of the A allele. Among G homozygotes, children of depressed mothers exhibited increased sensitivity in detecting sad faces, and reduced sensitivity in detecting happiness, compared to children of non-depressed mothers.

Influence of worry on sustained attention to emotional stimuli: evidence from the late positive potential

There is preliminary evidence to suggest that worry is associated with dysregulated emotion processing resulting from sustained attention to emotional versus neutral stimuli; however, this hypothesis has not been directly tested in prior research. Therefore, the current study used the event-related late positive potential (LPP) to directly examine if high levels of trait worry moderate sustained attention to emotional versus neutral stimuli. Electroencephalogram data was recorded while twenty-two women passively viewed neutral, positive, dysphoric, and threatening emotional images. Consistent with our hypotheses, higher levels of worry were associated with larger LPP amplitudes for emotional images but not neutral images. Importantly, the positive correlations between trait worry and LPP responses to threatening and positive images were maintained even when controlling for the influence of current anxiety symptoms, suggesting that worry may influence emotion processing whether or not the person is currently anxious. This sustained attention to emotional information may be one mechanism underlying how trait worry increases risk for anxiety disorders.

The best of both worlds: emotional cues improve prospective memory execution and reduce repetition errors

Prospective memory (PM) errors are commonly investigated as failures to execute an intended task (e.g., taking medication), and some studies suggest that emotional PM cues significantly reduce such failures. In Experiment 1, we extended these findings and additionally explored whether improved PM performance with emotional cues comes at the expense of performance on the ongoing task. Our results indicated that both younger and older adults are more likely to respond to emotional than to neutral PM cues, but the emotional cues did not differentially disrupt the performance on the ongoing task for either age group. Because older adults are also prone to mistakenly repeating a completed PM task, in Experiment 2 we further examined whether emotional PM cues increased repetition errors for older adults. Despite equivalent opportunity for repetition errors across cue type, older adults committed significantly fewer repetition errors with emotional than with neutral cues. Thus, these experiments demonstrated that older adults can effectively use emotional cues to help them initiate actions and to minimize repetition errors.

General distress, hopelessness-suicidal ideation and worrying in adolescence: concurrent and predictive validity of a symptom-level bifactor model for clinical diagnoses

BACKGROUND

Clinical disorders often share common symptoms and aetiological factors. Bifactor models acknowledge the role of an underlying general distress component and more specific sub-domains of psychopathology which specify the unique components of disorders over and above a general factor.

METHODS

A bifactor model jointly calibrated data on subjective distress from The Mood and Feelings Questionnaire and the Revised Children's Manifest Anxiety Scale. The bifactor model encompassed a general distress factor, and specific factors for (a) hopelessness-suicidal ideation, (b) generalised worrying and (c) restlessness-fatigue at age 14 which were related to lifetime clinical diagnoses established by interviews at ages 14 (concurrent validity) and current diagnoses at 17 years (predictive validity) in a British population sample of 1159 adolescents.

RESULTS

Diagnostic interviews confirmed the validity of a symptom-level bifactor model. The underlying general distress factor was a powerful but non-specific predictor of affective, anxiety and behaviour disorders. The specific factors for hopelessness-suicidal ideation and generalised worrying contributed to predictive specificity. Hopelessness-suicidal ideation predicted concurrent and future affective disorder; generalised worrying predicted concurrent and future anxiety, specifically concurrent generalised anxiety disorders. Generalised worrying was negatively associated with behaviour disorders.

LIMITATIONS

The analyses of gender differences and the prediction of specific disorders was limited due to a low frequency of disorders other than depression.

CONCLUSIONS

The bifactor model was able to differentiate concurrent and predict future clinical diagnoses. This can inform the development of targeted as well as non-specific interventions for prevention and treatment of different disorders.

Anatomical characterisation of the cricothyroid membrane in females of childbearing age using computed tomography

BACKGROUND

In the event of failure to secure the airway by conventional means, it may be necessary to perform invasive airway access via the cricothyroid membrane. No studies have addressed anatomy of this structure in the obstetric population. We aimed to review the anatomical variation of this structure in a population of childbearing age.

METHODS

We searched the radiology database for computed tomography studies of the neck performed in a 13-month period in consecutive patients aged 15-55 years. Studies on 18 females and 22 males were reviewed. Male patients were included for comparison. Data were reconstructed using a high spatial frequency algorithm to optimise spatial resolution. Five parameters were measured: distance from the skin to the membrane, maximum midline height of the membrane in the vertical plane, maximum transverse diameter of the membrane, neck diameter and cartilaginous calcification.

RESULTS

The distance (mean range) from skin to the membrane was similar in females and males (16.2 [3-33] vs. 13.9 [3-37] mm, P = 0.42). The vertical height (9.9 [7-17] vs. 11.4 [8-15] mm, P = 0.04) and maximum width of the membrane (14.5 [10-17] mm vs. 12.5 [10-15] mm, P < 0.01) were greater in males. Cartilaginous calcification was low and did not differ between genders.

CONCLUSIONS

The cricothyroid membrane is not necessarily a superficial structure and consequently may be difficult to palpate. The smallest dimensions of the membrane indicate that smaller than recommended cricothyroidotomy devices may be required in some patients as the external diameter of commercial trocar devices and tracheal tubes may exceed 7 mm.