The Computational and Neural Substrates of Ambiguity Avoidance in Anxiety

Theoretical accounts have linked anxiety to intolerance of ambiguity. However, this relationship has not been well operationalized empirically. Here, we used computational and neuro-imaging methods to characterize anxiety-related differences in aversive decision-making under ambiguity and associated patterns of cortical activity. Adult human participants chose between two urns on each trial. The ratio of tokens ('O's and 'X's) in each urn determined probability of electrical stimulation receipt. A number above each urn indicated the magnitude of stimulation that would be received if a shock was delivered. On ambiguous trials, one of the two urns had tokens occluded. By varying the number of tokens occluded, we manipulated the extent of missing information. At higher levels of missing information, there is greater second order uncertainty, i.e., more uncertainty as to the probability of pulling a given type of token from the urn. Adult human participants demonstrated avoidance of ambiguous options which increased with level of missing information. Extent of 'information-level dependent' ambiguity aversion was significantly positively correlated with trait anxiety. Activity in both the dorsal anterior cingulate cortex and inferior frontal sulcus during the decision-making period increased as a function of missing information. Greater engagement of these regions, on high missing information trials, was observed when participants went on to select the ambiguous option; this was especially apparent in high trait anxious individuals. These findings are consistent with individuals vulnerable to anxiety requiring greater activation of frontal regions supporting rational decision-making to overcome a predisposition to engage in ambiguity avoidance at high levels of missing information.

Executive Function Assigns Value to Novel Goal-Congruent Outcomes

People often learn from the outcomes of their actions, even when these outcomes do not involve material rewards or punishments. How does our brain provide this flexibility? We combined behavior, computational modeling, and functional neuroimaging to probe whether learning from abstract novel outcomes harnesses the same circuitry that supports learning from familiar secondary reinforcers. Behavior and neuroimaging revealed that novel images can act as a substitute for rewards during instrumental learning, producing reliable reward-like signals in dopaminergic circuits. Moreover, we found evidence that prefrontal correlates of executive control may play a role in shaping flexible responses in reward circuits. These results suggest that learning from novel outcomes is supported by an interplay between high-level representations in prefrontal cortex and low-level responses in subcortical reward circuits. This interaction may allow for human reinforcement learning over arbitrarily abstract reward functions.

Impaired adaptation of learning to contingency volatility in internalizing psychopathology

Using a contingency volatility manipulation, we tested the hypothesis that difficulty adapting probabilistic decision-making to second-order uncertainty might reflect a core deficit that cuts across anxiety and depression and holds regardless of whether outcomes are aversive or involve reward gain or loss. We used bifactor modeling of internalizing symptoms to separate symptom variance common to both anxiety and depression from that unique to each. Across two experiments, we modeled performance on a probabilistic decision-making under volatility task using a hierarchical Bayesian framework. Elevated scores on the common internalizing factor, with high loadings across anxiety and depression items, were linked to impoverished adjustment of learning to volatility regardless of whether outcomes involved reward gain, electrical stimulation, or reward loss. In particular, high common factor scores were linked to dampened learning following better-than-expected outcomes in volatile environments. No such relationships were observed for anxiety- or depression-specific symptom factors.

Effect of Prefrontal Cortex Stimulation on Regulation of Amygdala Response to Threat in Individuals With Trait Anxiety: A Randomized Clinical Trial

Importance

Transcranial direct current stimulation (tDCS) of the dorsolateral prefrontal cortex (DLPFC) is under clinical investigation as a treatment for major depressive disorder. However, the mechanisms of action are unclear, and there is a lack of neuroimaging evidence, particularly among individuals with affective dysfunction. Furthermore, there is no direct causal evidence among humans that the prefrontal-amygdala circuit functions as described in animal models (ie, that increasing activity in prefrontal cortical control regions inhibits amygdala response to threat).

Objective

To determine whether stimulation of the prefrontal cortex reduces amygdala threat reactivity in individuals with trait anxiety.

Design, Setting, and Participants

This community-based randomized clinical trial used a double-blind, within-participants design (2 imaging sessions per participant). Eighteen women with high trait anxiety (age range, 18-42 years) who scored greater than 45 on the trait measure of State-Trait Anxiety Inventory were randomized to receive active or sham tDCS of the DLPFC during the first session and the other intervention during the next session. Each intervention was followed immediately by a functional imaging scan during which participants performed an attentional task requiring them to ignore threatening face distractors. Data were collected from May 7 to October 6, 2015.

Main Outcomes and Measures

Amygdala threat response, measured with functional magnetic resonance imaging.

Results

Data from 16 female participants (mean age, 23 years; range, 18-42 years), with 8 in each group, were analyzed. Compared with sham stimulation, active DLPFC stimulation significantly reduced bilateral amygdala threat reactivity (z = 3.30, P = .04) and simultaneously increased activity in cortical regions associated with attentional control (z = 3.28, P < .001). In confirmatory behavioral analyses, there was a mean improvement in task accuracy of 12.2% (95% CI, 0.30%-24.0%; mean [SD] difference in number of correct answers, 2.2 [4.5]; t15 = 1.94, P = .04) after active DLPFC stimulation.

Conclusions and Relevance

These results reveal a causal role for prefrontal regulation of amygdala function in attentional capture by threat in individuals with high trait anxiety. The finding that prefrontal stimulation acutely increases attentional control signals and reduces amygdala threat reactivity may indicate a neurocognitive mechanism that could contribute to tDCS treatment effects in affective disorders.

Trial Registration

isrctn.org Identifier: ISRCTN78638425.

Anxiety, Depression, and Decision Making: A Computational Perspective

In everyday life, the outcomes of our actions are rarely certain. Further, we often lack the information needed to precisely estimate the probability and value of potential outcomes as well as how much effort will be required by the courses of action under consideration. Under such conditions of uncertainty, individual differences in the estimation and weighting of these variables, and in reliance on model-free versus model-based decision making, have the potential to strongly influence our behavior. Both anxiety and depression are associated with difficulties in decision making. Further, anxiety is linked to increased engagement in threat-avoidance behaviors and depression is linked to reduced engagement in reward-seeking behaviors. The precise deficits, or biases, in decision making associated with these common forms of psychopathology remain to be fully specified. In this article, we review evidence for which of the computations supporting decision making are altered in anxiety and depression and consider the potential consequences for action selection. In addition, we provide a schematic framework that integrates the findings reviewed and will hopefully be of value to future studies.

Stratification of MDD and GAD patients by resting state brain connectivity predicts cognitive bias

Patients with Generalized Anxiety Disorder (GAD) and Major Depressive Disorder (MDD) show between-group comorbidity and symptom overlap, and within-group heterogeneity. Resting state functional connectivity might provide an alternate, biologically informed means by which to stratify patients with GAD or MDD. Resting state functional magnetic resonance imaging data were acquired from 23 adults with GAD, 21 adults with MDD, and 27 healthy adult control participants. We investigated whether within- or between-network connectivity indices from five resting state networks predicted scores on continuous measures of depression and anxiety. Successful predictors were used to stratify participants into two new groups. We examined whether this stratification predicted attentional bias towards threat and whether this varied between patients and controls. Depression scores were linked to elevated connectivity within a limbic network including the amygdala, hippocampus, VMPFC and subgenual ACC. Patients with GAD or MDD with high limbic connectivity showed poorer performance on an attention-to-threat task than patients with low limbic connectivity. No parallel effect was observed for control participants, resulting in an interaction of clinical status by resting state group. Our findings provide initial evidence for the external validity of stratification of MDD and GAD patients by functional connectivity markers. This stratification cuts across diagnostic boundaries and might valuably inform future intervention studies. Our findings also highlight that biomarkers of interest can have different cognitive correlates in individuals with versus without clinically significant symptomatology. This might reflect protective influences leading to resilience in some individuals but not others.

Distinct frontal and amygdala correlates of change detection for facial identity and expression

Recruitment of 'top-down' frontal attentional mechanisms is held to support detection of changes in task-relevant stimuli. Fluctuations in intrinsic frontal activity have been shown to impact task performance more generally. Meanwhile, the amygdala has been implicated in 'bottom-up' attentional capture by threat. Here, 22 adult human participants took part in a functional magnetic resonance change detection study aimed at investigating the correlates of successful (vs failed) detection of changes in facial identity vs expression. For identity changes, we expected prefrontal recruitment to differentiate 'hit' from 'miss' trials, in line with previous reports. Meanwhile, we postulated that a different mechanism would support detection of emotionally salient changes. Specifically, elevated amygdala activation was predicted to be associated with successful detection of threat-related changes in expression, over-riding the influence of fluctuations in top-down attention. Our findings revealed that fusiform activity tracked change detection across conditions. Ventrolateral prefrontal cortical activity was uniquely linked to detection of changes in identity not expression, and amygdala activity to detection of changes from neutral to fearful expressions. These results are consistent with distinct mechanisms supporting detection of changes in face identity vs expression, the former potentially reflecting top-down attention, the latter bottom-up attentional capture by stimulus emotional salience.

Functional Connectivity under Anticipation of Shock: Correlates of Trait Anxious Affect versus Induced Anxiety

Sustained anxiety about potential future negative events is an important feature of anxiety disorders. In this study, we used a novel anticipation of shock paradigm to investigate individual differences in functional connectivity during prolonged threat of shock. We examined the correlates of between-participant differences in trait anxious affect and induced anxiety, where the latter reflects changes in self-reported anxiety resulting from the shock manipulation. Dissociable effects of trait anxious affect and induced anxiety were observed. Participants with high scores on a latent dimension of anxious affect showed less increase in ventromedial pFC-amygdala connectivity between periods of safety and shock anticipation. Meanwhile, lower levels of induced anxiety were linked to greater augmentation of dorsolateral pFC-anterior insula connectivity during shock anticipation. These findings suggest that ventromedial pFC-amygdala and dorsolateral pFC-insula networks might both contribute to regulation of sustained fear responses, with their recruitment varying independently across participants. The former might reflect an evolutionarily old mechanism for reducing fear or anxiety, whereas the latter might reflect a complementary mechanism by which cognitive control can be implemented to diminish fear responses generated due to anticipation of aversive stimuli or events. These two circuits might provide complementary, alternate targets for exploration in future pharmacological and cognitive intervention studies.

Seeing the world through non rose-colored glasses: anxiety and the amygdala response to blended expressions

Anxious individuals have a greater tendency to categorize faces with ambiguous emotional expressions as fearful (Richards et al., 2002). These behavioral findings might reflect anxiety-related biases in stimulus representation within the human amygdala. Here, we used functional magnetic resonance imaging (fMRI) together with a continuous adaptation design to investigate the representation of faces from three expression continua (surprise-fear, sadness-fear, and surprise-sadness) within the amygdala and other brain regions implicated in face processing. Fifty-four healthy adult participants completed a face expression categorization task. Nineteen of these participants also viewed the same expressions presented using type 1 index 1 sequences while fMRI data were acquired. Behavioral analyses revealed an anxiety-related categorization bias in the surprise-fear continuum alone. Here, elevated anxiety was associated with a more rapid transition from surprise to fear responses as a function of percentage fear in the face presented, leading to increased fear categorizations for faces with a mid-way blend of surprise and fear. fMRI analyses revealed that high trait anxious participants also showed greater representational similarity, as indexed by greater adaptation of the Blood Oxygenation Level Dependent (BOLD) signal, between 50/50 surprise/fear expression blends and faces from the fear end of the surprise-fear continuum in both the right amygdala and right fusiform face area (FFA). No equivalent biases were observed for the other expression continua. These findings suggest that anxiety-related biases in the processing of expressions intermediate between surprise and fear may be linked to differential representation of these stimuli in the amygdala and FFA. The absence of anxiety-related biases for the sad-fear continuum might reflect intermediate expressions from the surprise-fear continuum being most ambiguous in threat-relevance.

Moderate threat causes longer lasting disruption to processing in anxious individuals

Anxiety is associated with increased attentional capture by threat. Previous studies have used simultaneous or briefly separated (<1 s) presentation of threat distractors and target stimuli. Here, we tested the hypothesis that high trait anxious participants would show a longer time window within which distractors cause disruption to subsequent task processing, and that this would particularly be observed for stimuli of moderate or ambiguous threat value. A novel temporally separated emotional distractor task was used. Face or house distractors were presented for 250 ms at short (∼1.6 s) or long (∼3 s) intervals prior to a letter string comprising Xs or Ns. Trait anxiety was associated with slowed identification of letter strings presented at long intervals after face distractors with part surprise/part fear expressions. In other words, these distractors had an impact on high anxious individuals’ speed of target identification seconds after their offset. This was associated with increased activity in the fusiform gyrus and amygdala and reduced dorsal anterior cingulate recruitment. This pattern of activity may reflect impoverished recruitment of reactive control mechanisms to damp down stimulus-specific processing in subcortical and higher visual regions. These findings have implications for understanding how threat-related attentional biases in anxiety may lead to dysfunction in everyday settings where stimuli of moderate, potentially ambiguous, threat value such as those used here are fairly common, and where attentional disruption lasting several seconds may have a profound impact.

Resting state correlates of subdimensions of anxious affect

Resting state fMRI may help identify markers of risk for affective disorder. Given the comorbidity of anxiety and depressive disorders and the heterogeneity of these disorders as defined by DSM, an important challenge is to identify alterations in resting state brain connectivity uniquely associated with distinct profiles of negative affect. The current study aimed to address this by identifying differences in brain connectivity specifically linked to cognitive and physiological profiles of anxiety, controlling for depressed affect. We adopted a two-stage multivariate approach. Hierarchical clustering was used to independently identify dimensions of negative affective style and resting state brain networks. Combining the clustering results, we examined individual differences in resting state connectivity uniquely associated with subdimensions of anxious affect, controlling for depressed affect. Physiological and cognitive subdimensions of anxious affect were identified. Physiological anxiety was associated with widespread alterations in insula connectivity, including decreased connectivity between insula subregions and between the insula and other medial frontal and subcortical networks. This is consistent with the insula facilitating communication between medial frontal and subcortical regions to enable control of physiological affective states. Meanwhile, increased connectivity within a frontoparietal-posterior cingulate cortex-precunous network was specifically associated with cognitive anxiety, potentially reflecting increased spontaneous negative cognition (e.g., worry). These findings suggest that physiological and cognitive anxiety comprise subdimensions of anxiety-related affect and reveal associated alterations in brain connectivity.

Unraveling the anxious mind: anxiety, worry, and frontal engagement in sustained attention versus off-task processing

Much remains unknown regarding the relationship between anxiety, worry, sustained attention, and frontal function. Here, we addressed this using a sustained attention task adapted for functional magnetic resonance imaging. Participants responded to presentation of simple stimuli, withholding responses to an infrequent “No Go” stimulus. Dorsolateral prefrontal cortex (DLPFC) activity to “Go” trials, and dorsal anterior cingulate (dACC) activity to “No Go” trials were associated with faster error-free performance; consistent with DLPFC and dACC facilitating proactive and reactive control, respectively. Trait anxiety was linked to reduced recruitment of these regions, slower error-free performance, and decreased frontal-thalamo-striatal connectivity. This indicates an association between trait anxiety and impoverished frontal control of attention, even when external distractors are absent. In task blocks where commission errors were made, greater DLPFC-precuneus and DLPFC-posterior cingulate connectivity were associated with both trait anxiety and worry, indicative of increased off-task thought. Notably, unlike trait anxiety, worry was not linked to reduced frontal-striatal-thalamo connectivity, impoverished frontal recruitment, or slowed responding during blocks without commission errors, contrary to accounts proposing a direct causal link between worry and impoverished attentional control. This leads us to propose a new model of the relationship between anxiety, worry and frontal engagement in attentional control versus off-task thought.

COMT val158met genotype affects recruitment of neural mechanisms supporting fluid intelligence

Fluid intelligence (g(f)) influences performance across many cognitive domains. It is affected by both genetic and environmental factors. Tasks tapping g(f) activate a network of brain regions including the lateral prefrontal cortex (LPFC), the presupplementary motor area/anterior cingulate cortex (pre-SMA/ACC), and the intraparietal sulcus (IPS). In line with the "intermediate phenotype" approach, we assessed effects of a polymorphism (val(158)met) in the catechol-O-methyltransferase (COMT) gene on activity within this network and on actual task performance during spatial and verbal g(f) tasks. COMT regulates catecholaminergic signaling in prefrontal cortex. The val(158) allele is associated with higher COMT activity than the met(158) allele. Twenty-two volunteers genotyped for the COMT val(158)met polymorphism completed high and low g(f) versions of spatial and verbal problem-solving tasks. Our results showed a positive effect of COMT val allele load upon the blood oxygen level-dependent response in LPFC, pre-SMA/ACC, and IPS during high g(f) versus low g(f) task performance in both spatial and verbal domains. These results indicate an influence of the COMT val(158)met polymorphism upon the neural circuitry supporting g(f). The behavioral effects of val allele load differed inside and outside the scanner, consistent with contextual modulation of the relation between COMT val(158)met genotype and g(f) task performance.

Neurocognitive mechanisms of anxiety: an integrative account

Anxiety can be hugely disruptive to everyday life. Anxious individuals show increased attentional capture by potential signs of danger, and interpret expressions, comments and events in a negative manner. These cognitive biases have been widely explored in human anxiety research. By contrast, animal models have focused upon the mechanisms underlying acquisition and extinction of conditioned fear, guiding exposure-based therapies for anxiety disorders. Recent neuroimaging studies of conditioned fear, attention to threat and interpretation of emotionally ambiguous stimuli indicate common amygdala-prefrontal circuitry underlying these processes, and suggest that the balance of activity within this circuitry is altered in anxiety, creating a bias towards threat-related responses. This provides a focus for future translational research, and targeted pharmacological and cognitive interventions.

Neural Processing of Fearful Faces: Effects of Anxiety are Gated by Perceptual Capacity Limitations

Debate continues as to the automaticity of the amygdala's response to threat. Accounts taking a strong automaticity line suggest that the amygdala's response to threat is both involuntary and independent of attentional resources. Building on these accounts, prominent models have suggested that anxiety modulates the output of an amygdala-based preattentive threat evaluation system. Here, we argue for a modification of these models. Functional magnetic resonance imaging data were collected while volunteers performed a letter search task of high or low perceptual load superimposed on fearful or neutral face distractors. Neither high- nor low-anxious volunteers showed an increased amygdala response to threat distractors under high perceptual load, contrary to a strong automaticity account of amygdala function. Under low perceptual load, elevated state anxiety was associated with a heightened response to threat distractors in the amygdala and superior temporal sulcus, whereas individuals high in trait anxiety showed a reduced prefrontal response to these stimuli, consistent with weakened recruitment of control mechanisms used to prevent the further processing of salient distractors. These findings suggest that anxiety modulates processing subsequent to competition for perceptual processing resources, with state and trait anxiety having distinguishable influences upon the neural mechanisms underlying threat evaluation and "top-down" control.

COMT genotype influences prefrontal response to emotional distraction

Early studies of genetic effects on brain activity have been conducted to investigate primarily either the influence of polymorphisms in dopaminergic genes, especially the catechol-O-methyltransferase (COMT) gene, on prefrontal cognitive processes such as working memory, or that of polymorphisms in the serotonin transporter gene on the amygdala response to threatening stimuli. Here, we address genetic influences on the neural systems underlying cognitive-affective interactions. Specifically, we assess the effect of the CO MT val158met polymorphism onfrontal regulation of attentionunder emotional distraction. Healthy volunteers were scanned while performing a house-matching task with affectively negative versus neutral distractors. Effects of val allele load were examined on frontal regions associated with attentional control and emotion regulation, and on parahippocampal regions associated with perception of houses. As we predicted, val load correlated positively with activity in control- and task-related regions during performance under emotional distraction. These findings provide an initial step toward identifying genetic contributions to interindividual variability in recruitment of mechanisms that regulate affective processing.

State anxiety modulation of the amygdala response to unattended threat-related stimuli

Findings from fear-conditioning studies in rats and functional neuroimaging with human volunteers have led to the suggestion that the amygdala is involved in the preattentive detection of threat-related stimuli. However, some neuroimaging findings point to attentional modulation of the amygdala response. The clinical-cognitive literature suggests that the extent to which the processing of threat-related stimuli is modulated by attention is crucially dependent on participants' anxiety levels. Here, we conducted a functional magnetic resonance imaging study with 27 healthy volunteers to examine whether amygdala responsivity to unattended threat-related stimuli varies with individual differences in state anxiety. Pairs of houses and faces (both fearful or neutral in expression) were presented, and participants attended to either the faces or the houses and matched these stimuli on identity. "Low-anxious" participants showed a reduced amygdala response to unattended versus attended fearful faces, but "high-anxious" participants showed no such reduction, having an increased amygdala response to fearful versus neutral faces regardless of attentional focus. These findings suggest that anxiety may interact with attentional focus to determine the magnitude of the amygdala response to threat-related stimuli.

Memory for emotional stories in high and low depressed children

Cognitive theories of depression emphasise a vicious circle linking depressed mood and biased recall towards negative information. In line with this, depressed adults show selectively enhanced recall for negative information. This recall bias is held to be mediated by increased accessibility of negative self-referent schemas formed as a result of adverse early experiences. Given this, surprisingly few studies have examined depression-related recall biases from a developmental perspective. Clinically depressed children have been found to show enhanced recall of negative adjectives, particularly when self-referent, but to date there is no evidence for similar recall biases in non-clinically depressed groups. The current study addressed this by investigating high and low non-clinically depressed children's (aged 5-11 years) recall of emotional stories. High depressed children showed enhanced recall of negative stories, relative to positive stories, compared to the low depressed group. This did not vary with age group. We conclude that, when child-oriented materials are used, depression-related biases in recall towards negative information are observable even in a non-clinical sample of children from 5 years of age.

The youngest victims of child maltreatment: what happens to infants in a court sample?

Current data show that infants represent an increasing proportion of cases of child maltreatment. To learn more about how infants fare in the current system and to provide baseline data against which to compare outcomes following recent legislative reforms, this study examined a subsample of infants in a sample of 200 care and protection cases brought before the Boston Juvenile Court in 1994. Child, parent, and case characteristics of infants 0 to 3 months of age (n = 46) were compared with characteristics of older children in the sample. All cases were followed prospectively for 4 years, and data were abstracted from court records. Results revealed that the infants were primarily children of substance abusers who had extensive prior histories of child protective service system involvement. Although the majority of the infants were eventually permanently removed from parental custody and adopted, many experienced time delays and multiple placements before achieving permanent homes.

Maintaining and shifting attention within left or right hemifield

Positron emission tomography (PET) was used to examine two questions: (i) which structures of the intact human brain change their activity with the direction of attention to left or right visual field; and (ii) how does activity in these structures, and in parietal cortex in particular, depend on the frequency of attentional shifts? Subjects were required to discriminate the orientation of peripheral gratings. The two main experimental variables were the attended hemifield (left or right) and the proportion of trials requiring a shift within that hemifield (20% or 80%). A detection control condition was also included. Behaviourally, subjects were less accurate and significantly slower when a trial required a shift than when it did not. Ventral and lateral occipital areas showed significantly higher blood flow levels contralateral to the direction of attention. Replicating previous work, there was also a significant main effect of the direction of attention in left lateral prefrontal cortex: blood flow levels were higher during leftward attention in comparison both to baseline and to rightward attention. This left frontal effect reached significance in single subjects in whom several activation sites could be distinguished within left middle and inferior frontal gyrus. Right and left parietal cortex were activated during both left- and right-field attention conditions, with a tendency for higher activity levels when attention was directed contralaterally. Contrary to the experimental hypothesis, however, parietal regions were not activated differentially by high versus low numbers of attentional shifts. The current experiment confirms that left frontal convexity is sensitive to manipulations of the direction of visuospatial attention. The results do not indicate a specific role of parietal cortex in attentional shifting.

What progress has been made in meeting the needs of seriously maltreated children? The course of 200 cases through the Boston Juvenile Court

OBJECTIVES

The study examined child, parent, and case characteristics in a sample of 200 cases of serious child maltreatment brought before the Boston Juvenile Court (BJC) on Care and Protection petitions in 1994. Whether recent changes in Massachusetts law have been effective in reducing delays in adjudication and helping children achieve permanent placements more quickly was also examined.

METHOD

Data were abstracted from court records by the research team. The 200 cases were followed prospectively for 4 years. Retrospective data on the families' previous involvement with the protective service system were also abstracted from the records. Data from the 1994 cases were compared to that obtained from a sample of cases brought before the BJC in 1985-1986.

RESULTS

Children permanently removed from parental custody in the 1994 sample required less time post-disposition to achieve permanent placements. However, overall, time frames for the 1994 cases remained remarkably similar to those in 1985-1986: children were in the protective service system an average of 5 years; cases required an average of 1.6 years in court; and half of the children permanently removed from parental custody were still in "temporary" foster care at 4-year follow-up.

CONCLUSIONS

Although some improvements have occurred since 1985-1986, the system still fails to meet the needs of seriously maltreated children to achieve permanent placements promptly. The implications of the findings for system reform are discussed.

Auditory temporal processing impairment: neither necessary nor sufficient for causing language impairment in children

Fourteen twin pairs, aged 8 to 10 years, were tested 3 times over 12 months; they included 11 children with language impairment (LI), 11 control children matched on nonverbal ability and age, and 6 co-twins who did not meet criteria for LI or control status. Thresholds were estimated for detecting a brief backward-masked tone (BM), detection of frequency modulation (FM), and pitch discrimination using temporal cues (deltaf0). Both BM and FM thresholds improved with training, and by the 2nd test session, FM thresholds were in the adult range. There were marked individual differences on BM and deltaf0 and, for both tasks, performance correlated with Tallal's Auditory Repetition Task administered 2 years previously. However, no auditory measure gave significant differences between LI and control groups; performance was influenced more by nonverbal than language ability. Some children did have a stable pattern of poor performance on certain auditory tasks, but their good FM detection raised questions about whether processing of auditory temporal information is abnormal. We found no evidence that auditory deficits are a necessary or sufficient cause of language impairments.

Maternal social support patterns and child maltreatment: comparison of maltreating and nonmaltreating mothers

Compared to demographically matched mothers, maltreating mothers listed fewer friends in their social support networks, reported less contact with friends, and gave lower ratings of quality of support received from friends. Maternal depressive symptoms, quality of current relationships, and social support from friends were each independently associated with maltreatment status in logistic regression analysis. Implications for intervention and research are offered.

Different origin of auditory and phonological processing problems in children with language impairment: evidence from a twin study

This study investigated the heritability of auditory processing impairment, as assessed by Tallal's Auditory Repetition Test (ART). The sample consisted of 37 same-sex twin pairs who had previously been selected because one or both twins met criteria for language impairment (LI) and 104 same-sex twin pairs in the same age range (7 to 13 years) from the general population. These samples yielded 55 children who met criteria for LI, who were compared with 76 children whose language was normal for their age (LN group). We replicated earlier work showing that group LI is impaired relative to group LN on ART. However, there was no evidence of a heritable influence on ART scores: Correlations between twins and their co-twins were reasonably high for both MZ and DZ twins, suggesting that performance is more influenced by shared environment than genetic factors. Analyses of extreme scores gave a similar picture of nonsignificant group heritability. In contrast, a test of phonological short-term memory, the Children's Nonword Repetition Test (CNRep), gave high estimates of group heritability. In general, CNRep was a better predictor of low language test scores than ART, but ART did make a significant independent contribution in accounting for variance in a test of grammatical understanding.

"Twin language": a risk factor for language impairment?

Retrospective parental report of earlier "twin language" was obtained for two groups of twins. Sample G consisted of 94 twin pairs between the ages of 7 and 13 years recruited through the school system as a general population sample. Sample L consisted of 82 twin pairs between the ages of 7 and 13 years who had been recruited for a genetic study; of these twin pairs at least one of the twins had a speech-language impairment persisting to school age. Parental report of twin language was higher (around 50%) for children with speech-language impairment than for those with normal language (11%). Consistent with this, children with twin language obtained significantly lower mean language scores than other children, although their mean nonverbal IQ was equivalent. The exceptions were a handful of children whose parents described use of a "private language" that coexisted alongside normal use of English. These findings are consistent with the view that what is described as twin language is usually use of immature or deviant language by two children at the same developmental level.

Predictors of behavior problems in preschool children of inner-city Afro-American and Puerto Rican adolescent mothers

Maternal reports on the Child Behavior Checklist/2-3 (CBCL/2-3) were used to evaluate child, maternal, and environmental predictors of behavior problems in 83 preschool children of disadvantaged adolescent mothers. CBCL/2-3 scores correlated modestly with independent ratings of child difficult behaviors observed in videotaped mother-child play interactions. 13% of children had scores in the clinical range. Significant correlations were consistently found between CBCL/2-3 ratings and maternal depressive symptoms, social supports, and life stress--assessed 3 times during the first year postpartum. In hierarchical regression analyses, maternal depressive symptoms, residence with the adolescent's mother, and perceived emotional support from friends contributed most to the explained variance. A significant ethnicity x child gender interaction term also suggested that African American mothers of male children reported more behavioral problems. Findings evidence the heterogeneity of outcomes for children of disadvantaged adolescent mothers but also demonstrate how correlates of poverty negatively affect their socioemotional development.

Screening for psychosocial dysfunction in inner-city children: further validation of the Pediatric Symptom checklist

A sample of 123 6- to 12-year-old outpatients at an inner-city pediatric clinic was screened for psychosocial dysfunction using the Pediatric Symptom Checklist (PSC), a brief parent-completed questionnaire. The prevalence of positive screening scores on the PSC was 22%, significantly higher than the rate found in lower middle to upper middle-class samples. Comparing PSC case classifications with comprehensive assessments made by clinicians, overall agreement was 92% (kappa = 0.82; sensitivity = 88%; specificity = 100%); a comparison with several other measures provided additional support for the validity of the PSC. The PSC's reliability over time was also acceptable. These findings provide preliminary evidence that the PSC is as valid and reliable for screening children from economically disadvantaged and minority backgrounds as it is for middle and upper middle-class populations.

Screening for psychosocial dysfunction in pediatric practice. A naturalistic study of the Pediatric Symptom Checklist

This study examined the routine implementation of the Pediatric Symptom Checklist (PSC), a brief questionnaire which screens for psychosocial dysfunction in school-aged children in an outpatient pediatric practice. Results indicated that the PSC was well-accepted by parents and adequately tolerated by busy clinic staff. When the PSC was included as part of the standard procedure for well-child visits, the referral rate for psychosocial problems due to positive PSC scores rose to 12% from the clinic baseline referral rate of 1.5%, a significant increase (P < .01). Half of the children who screened positive on the PSC had not been previously identified by their pediatricians as having psychosocial problems, and more than half had never received any psychological treatment. When implementation of the PSC was discontinued, the referral rate fell to 2%, a rate similar to baseline. The findings suggest that it is possible to incorporate the PSC into routine pediatric practice and that the PSC can help pediatricians identify and better serve children experiencing psychosocial difficulties. The study also suggests that further work is needed to understand the barriers to ongoing implementation.

Screening for psychosocial dysfunction in pediatric dermatology practice

The Pediatric Symptom Checklist, a brief psychosocial screening questionnaire, was used in a multi-center study of pediatric dermatology clinics (n = 377). Overall rates of positive screening indicated that approximately 13% of patients screened positive, a rate similar to findings in primary care pediatric settings. Examining the sample in greater detail demonstrated that children whose dermatologic disorder is perceived to have a greater impact on their appearance are at higher risk for psychosocial dysfunction.

Screening for dysfunction in the children of outpatients at a psychopharmacology clinic

OBJECTIVE

The goals of this study were 1) to determine whether the use of the Pediatric Symptom Checklist in an adult-oriented psychiatric practice was feasible, 2) to determine if scores indicative of dysfunction on the Pediatric Symptom Checklist were associated with parental or background factors, 3) to determine whether children flagged by their scores on the Pediatric Symptom Checklist were receiving psychiatric services, and 4) to compare the psychosocial dysfunction in this group of children with that found in children screened as part of routine pediatric visits.

METHOD

Adult outpatients in a hospital's clinical psychopharmacology unit were asked to complete the Pediatric Symptom Checklist regarding their children. These patients were the parents of 100 school-aged children. Factors such as the parents' diagnoses and demographic variables were also examined.

RESULTS

The Pediatric Symptom Checklist was readily accepted by parents and fit easily into the routine of general psychiatric practice. Significantly more of the children of these outpatients than of children in comparable pediatric offices had scores indicative of psychiatric dysfunction (scores above the cutoff). Children of parents who were single, of low socioeconomic status, or with a diagnosis of personality (especially borderline) or mood disorder were more likely to have scores above the cutoff. More than a third of the children who had scores above the cutoff on the Pediatric Symptom Checklist were not currently receiving psychiatric services.

CONCLUSIONS

The Pediatric Symptom Checklist provided a rapid and simple method for general psychiatrists to identify psychosocial dysfunction in their patients' children.

Psychosocial screening in pediatric practice: a survey of interested physicians

This study followed up on 201 pediatricians and family practitioners who had requested information about the Pediatric Symptom Checklist (PSC), a parent-completed questionnaire which screens for psychosocial dysfunction in school-aged children. The physicians were sent a postcard survey asking whether they had used the PSC in their practices. Of the 157 (78%) who responded to the postcard survey, 36 (23%) reported that they had used the PSC. On a follow-up questionnaire, all of these physicians rated the PSC as useful, and nearly 80% reported that it led to increased case-finding and/or referrals. Ninety-six percent stated that they will continue to use the PSC; more than half of them routinely or frequently. The findings indicate a widespread interest in psychosocial screening, and suggest that additional educational efforts may be necessary to support the acceptance of the PSC in pediatric practice.

Influence of new quinolones on normal immune capabilities

Ciprofloxacin, pefloxacin, norfloxacin, and ofloxacin were investigated for immunomodulatory activity on humoral and cell-mediated immune responses. Ciprofloxacin and pefloxacin altered the humoral immune responses of mice to sheep red blood cells. This effect was not exhibited by norfloxacin or ofloxacin. All four quinolones did not alter cell-mediated responses. When these antimicrobial agents were tested for their interaction with human polymorphonuclear phagocytic activity, all agents suppressed this activity. In addition, all except norfloxacin showed anti-inflammatory activity.

Effects of artemisinin, dihydroartemisinin and arteether on immune responses of normal mice

Artemisinin (Qinghaosu) is a potent antimalarial sesquiterpene lactone isolated from the Chinese herb Artemisia annua. Arteether, a potent semisynthetic analogue of dihydroartemisinin is being developed by the World Health Organization as the artemisinin derivative of choice for the treatment of malaria. All three agents in doses of 400 and 600 mg/kg body weight were found to exhibit marked suppression of humoral responses, as measured by the hemolytic plaque assay, with arteether being the most potent. These agents did not alter the delayed-type hypersensitivity response to sheep erythrocytes at the same dose levels. In addition, all three agents were found not to possess any anti-inflammatory activity when tested on carrageenan-induced oedema. These results indicated that these agents have a selective immunosuppressive activity. They did not exhibit immunostimulating activity in contrast to what has been reported for sodium artesunate.