Contribution of parenting to complex syntax development in preschool children with developmental delays or typical development.

BACKGROUND: Despite studies of how parent-child interactions relate to early child language development, few have examined the continued contribution of parenting to more complex language skills through the preschool years. The current study explored how positive and negative parenting behaviours relate to growth in complex syntax learning from child age 3 to age 4 years, for children with typical development or developmental delays (DDs). METHODS: Participants were children with or without DD (N = 60) participating in a longitudinal study of development. Parent-child interactions were transcribed and coded for parenting domains and child language. Multiple regression analyses were used to identify the contribution of parenting to complex syntax growth in children with typical development or DD. RESULTS: Analyses supported a final model, F(9,50) = 11.90, P < .001, including a significant three-way interaction between positive parenting behaviours, negative parenting behaviours and child delay status. This model explained 68.16% of the variance in children's complex syntax at age 4. Simple two-way interactions indicated differing effects of parenting variables for children with or without DD. CONCLUSIONS: Results have implications for understanding of complex syntax acquisition in young children, as well as implications for interventions.

The effects of early positive parenting and developmental delay status on child emotion dysregulation.

BACKGROUND: Emotion regulation has been identified as a robust predictor of adaptive functioning across a variety of domains (Aldao et al. ). Furthermore, research examining early predictors of competence and deficits in ER suggests that factors internal to the individual (e.g. neuroregulatory reactivity, behavioural traits and cognitive ability) and external to the individual (e.g. caregiving styles and explicit ER training) contribute to the development of ER (Calkins ). Many studies have focused on internal sources or external sources; however, few have studied them simultaneously within one model, especially in studies examining children with developmental delays (DD). Here, we addressed this specific research gap and examined the contributions of one internal factor and one external factor on emotion dysregulation outcomes in middle childhood. Specifically, our current study used structural equation modelling (SEM) to examine prospective, predictive relationships between DD status, positive parenting at age 4 years and child emotion dysregulation at age 7 years. METHOD: Participants were 151 families in the Collaborative Family Study, a longitudinal study of young children with and without DD. A positive parenting factor was composed of sensitivity and scaffolding scores from mother-child interactions at home and in the research centre at child age 4 years. A child dysregulation factor was composed of a dysregulation code from mother-child interactions and a parent-report measure of ER and lability/negativity at age 7 years. Finally, we tested the hypothesis that positive parenting would mediate the relationship between DD and child dysregulation. RESULTS: Mothers of children with DD exhibited fewer sensitive and scaffolding behaviours compared with mothers of typically developing children, and children with DD were more dysregulated on all measures of ER. SEM revealed that both DD status and early positive parenting predicted emotion dysregulation in middle childhood. Furthermore, findings provided support for our hypothesis that early positive parenting mediated the relationship between DD and dysregulation. CONCLUSIONS: This work enhances our understanding of the development of ER across childhood and how endogenous child factors (DD status) and exogenous family factors (positive parenting) affect this process. Our findings provide clear implications for early intervention programmes for children with DD. Because of the predictive relationships between (a) developmental status and ER and (b) parenting and ER, the results imply that sensitive parenting behaviours should be specifically targeted in parent interventions for children with DD.

Maternal control and early child dysregulation: Moderating roles of ethnicity and child delay status.

BACKGROUND: Maternal controlling behaviour has been found to influence child development, particularly in behavioural and emotional regulation. Given the higher rates of interfering parent control found in mothers of children with developmental delays (DD) and Latina mothers, their children could be at increased risk for behavioural and emotional dysregulation. While studies generally support this increased risk for children with DD, findings for Latino children are mixed and often attributed to cultural models of child rearing. The present study sought to determine the moderating roles of child DD and mother ethnicity in determining the relationships between two types of parent control (supportive directiveness and interference) and child dysregulation over time. METHODS: The present study, involving 178 3-year old children with DD (n = 80) or typical development (n = 98), examined observed parent control (directive versus interfering) of Latina and Anglo mothers as it relates to change in preschool child dysregulation over 2 years. RESULTS: Interfering parent control was greater for children with DD and also for Latino mothers. Supportive directive parenting generally related to relatively greater decline in child behaviour and emotion dysregulation over time, while interfering parenting generally related to less decline in child behaviour dysregulation over time. In Anglo but not Latino families, these relationships tended to vary as a function of child disability. CONCLUSIONS: Parent directives that support, rather than deter, ongoing child activity may promote positive regulatory development. These results particularly hold for children with DD and Latino families, and have implications for parenting practices and intervention.

Unsupportive parenting and internalising behaviour problems in children with or without intellectual disability.

BACKGROUND: Children with intellectual disability (ID) are at heightened risk for developing other psychological disorders, including internalising disorders. Anxiety and depression have been shown to be familial, and parenting is a contributing factor to the development of these disorders. To extend this research, we examined the extent to which mother and father depression and negative, unsupportive parenting related to child internalising behaviour problems, in children with ID or with typical development (TD). METHOD: Participants were 156 mother and father dyads and their children, assessed at ages 4 and 5 years. We examined parent (mother and father) and child delay status (ID and TD) in relation to measures of both observed and self-reported unsupportive, negative parenting. Utilising moderation models, we examined the relationship between parental depression, unsupportive/negative parenting and child internalising behaviour problems. RESULTS: Unsupportive, negative parenting differed based on parent gender and child delay status. In addition, father depression was a significant moderator of the relationship between unsupportive parenting and child internalising behaviour problems. CONCLUSIONS: Children with ID were found to be at higher risk of experiencing unsupportive, negative parenting than children with TD. Children of depressed fathers were especially vulnerable to developing internalising behaviour problems in an unsupportive parenting context.

Bullying of youth with autism spectrum disorder, intellectual disability, or typical development: Victim and parent perspectives.

In-depth interviews conducted separately with 13-year-olds with autism spectrum disorder (ASD), intellectual disability (ID), or typical development (TD) and their mothers investigated the experiences of victimization in the form of bullying. Coded constructs from the interviews were utilized to compare groups on the frequency, type, and impact of victimization. Youth with ASD were victimized more frequently than their ID or TD peers, and the groups differed with regard to the type of bullying and the impact it had, with ASD youth faring the worst. Higher internalizing problems and conflict in friendships were found to be significant predictors of victimization, according to both youth- and mother-reports. These predictors were found to be more salient than ASD status alone. Implications for practice are discussed.

Resilient parenting of preschool children at developmental risk.

BACKGROUND: Given the great benefits of effective parenting to child development under normal circumstances, and the even greater benefits in the face of risk, it is important to understand why some parents manage to be effective in their interactions with their child despite facing formidable challenges. This study examined factors that promoted effective parenting in the presence of child developmental delay, high child behaviour problems, and low family income. METHOD: Data were obtained from 232 families at child age 3 and 5 years. Using an adapted ABCX model, we examined three risk domains (child developmental delay, child behaviour problems, and low family income) and three protective factors (mother's education, health, and optimism). The outcome of interest was positive parenting as coded from mother-child interactions. RESULTS: Levels of positive parenting differed across levels of risk. Education and optimism appeared to be protective factors for positive parenting at ages 3 and 5, and health appeared to be an additional protective factor at age 5. There was an interaction between risk and education at age 3; mothers with higher education engaged in more positive parenting at higher levels of risk than did mothers with less education. There was also an interaction between risk and optimism at age 3; mothers with higher optimism engaged in more positive parenting at lower levels of risk than did mothers with less optimism. The risk index did not predict change in positive parenting from age 3-5, but the protective factor of maternal health predicted positive changes. CONCLUSIONS: This study examined factors leading to positive parenting in the face of risk, a topic that has received less attention in the literature on disability. Limitations, future directions, and implications for intervention are discussed.

Parent-child problem solving in families of children with or without intellectual disability.

OBJECTIVE: To examine differences in child social competence and parent-child interactions involving children with intellectual disability (ID) or typical development (TD) during a Parent-Child Problem-Solving Task. DESIGN: Mothers and their 9-year-old children (n = 122) participated in a problem-solving task in which they discussed and tried to resolve an issue they disagreed about. The interactions were coded on child and mother problem solving and affect behaviours, as well as the dyad's problem resolution. RESULTS: Children with ID (n = 35) were rated lower on expression/negotiation skills and higher on resistance to the task than children with TD (n = 87). Mothers in the ID group (vs. TD group) were more likely to direct the conversation. However, there were no group differences on maternal feeling acknowledgement, engagement, warmth or antagonism. The ID dyads were less likely to come to a resolution and to compromise in doing so than the TD dyads. These group differences were not attributable to differences in children's behaviour problems. CONCLUSIONS: Children with ID and their mothers had more difficulty resolving problems, and this increased difficulty was not explained by greater behaviour problems. Additionally, with the exception of directiveness, mothers of children with ID displayed similar behaviours and affect towards their children during problem solving as mothers of children with TD. Results suggest that the Parent-Child Problem-Solving Task is a useful way to assess social skills and associated parental behaviours in middle childhood beyond self-report. Implications for future research and intervention are discussed.

Emotion dysregulation and social competence: stability, change and predictive power.

BACKGROUND: Social difficulties are closely linked to emotion dysregulation among children with typical development (TD). Children with developmental delays (DD) are at risk for poor social outcomes, but the relationship between social and emotional development within this population is not well understood. The current study examines the extent to which emotion dysregulation is related to social problems across middle childhood among children with TD or DD. METHOD: Children with TD (IQ ≥ 85, n = 113) and children with DD (IQ ≤ 75, n = 61) participated in a longitudinal study. Annual assessments were completed at ages 7, 8 and 9 years. At each assessment, mothers reported on children's emotion dysregulation, and both mothers and teachers reported on children's social difficulties. RESULTS: Children with DD had higher levels of emotion dysregulation and social problems at each age than those with TD. Emotion dysregulation and social problems were significantly positively correlated within both TD and DD groups using mother report of social problems, and within the TD group using teacher report of social problems. Among children with TD, emotion dysregulation consistently predicted change in social problems from one year to the next. However, among children with DD, emotion dysregulation offered no unique prediction value above and beyond current social problems. CONCLUSIONS: Results suggested that the influence of emotion regulation abilities on social development may be a less salient pathway for children with DD. These children may have more influences, beyond emotion regulation, on their social behaviour, highlighting the importance of directly targeting social skill deficits among children with DD in order to ameliorate their social difficulties.

Attention-deficit/hyperactivity disorder among children with and without intellectual disability: an examination across time.

BACKGROUND: Children with intellectual and developmental disabilities are at heightened risk for mental disorders, and disruptive behaviour disorders appear to be the most prevalent. The current study is a longitudinal examination of attention-deficit/hyperactivity disorder (ADHD) among children with and without intellectual disability (ID) across ages 5 to 8. METHOD: We assessed 228 5-year-old children, 87 with ID and 141 with typical development (TD), for clinical diagnoses using a structured interview. These interviews were conducted with mothers annually from child age 5 to 8. RESULTS: Attention-deficit/hyperactivity disorder was over 3 times as prevalent in the ID group as in the TD group across ages 5, 6, 7 and 8. The diagnosis of ADHD tended to emerge earlier and was more stable in the ID group; however, the total number and relative frequency of ADHD symptoms endorsed appeared to be similar within the two groups across time. With respect to the developmental course, the trajectories of ADHD inattentive and hyperactive/impulsive symptoms over time were similar in the two groups. DISCUSSION: Children with ID appear to be at heightened risk for ADHD and they may experience a longer and more persistent course of the disorder. These findings highlight the need for making interventions available for early treatment of this condition in children with ID.

The role of marital quality and spousal support in behaviour problems of children with and without intellectual disability.

BACKGROUND: Children with intellectual disability (ID) have been found to be at an increased risk for developing behavioural problems. The purpose of this study was to examine the relationship between the marital domain, including marital quality and spousal support, and behaviour problems in children with and without ID. METHODS: The relationship between the marital domain and child behaviour problems was examined in 132 families of 6-year-olds with and without ID. Using hierarchical regression, these relationships were also studied over time from child ages 6-8 years. Child behaviour problems were assessed with mother-reported Child Behavior Checklist. The marital domain was measured using the Dyadic Adjustment Scale-7 and the Spousal Support and Agreement Scale. Mother-reported parenting stress and observed parenting practices were tested as potential mediators of the relationship between the marital domain and child behaviour problems. RESULTS: Mean levels of the marital domain were not significantly different between typically developing (TD) and ID groups, but there were significantly greater levels of variance in reported marital quality in the ID group at ages 6, 7 and 8. The marital domain score at child age 6 years predicted child behaviour problems at age 8 for the TD group only. This predictive relationship appeared to be a unidirectional effect, as child behaviour problems at age 6 were not found to predict levels of the marital domain at age 8. Parenting stress partially mediated this relationship for the TD group. CONCLUSIONS: The marital domain may have a greater impact on behavioural outcomes for TD children. Implications for future research and interventions are discussed.

Resilience and the course of daily parenting stress in families of young children with intellectual disabilities.

BACKGROUND: Parenting stresses have consistently been found to be higher in parents of children with intellectual disabilities (ID); yet, some families are able to be resilient and thrive in the face of these challenges. Despite the considerable research on stress in families of ID, there is still little known about the stability and compensatory factors associated with everyday parenting stresses. METHODS: Trajectories of daily parenting stress were studied for both mothers and fathers of children with ID across child ages 36-60 months, as were specific familial risk and resilience factors that affect these trajectories, including psychological well-being of each parent, marital adjustment and positive parent-child relationships. RESULTS: Mothers' daily parenting stress significantly increased over time, while fathers' daily parenting stress remained more constant. Decreases in mothers' daily parenting stress trajectory were associated with both mother and father's well-being and perceived marital adjustment, as well as a positive father-child relationship. However, decreases in fathers' daily parenting stress trajectory were only affected by mother's well-being and both parents' perceived marital adjustment. CONCLUSIONS: Parenting stress processes are not shared entirely across the preschool period in parents of children with ID. Although individual parent characteristics and high-quality dyadic relationships contribute to emerging resilience in parents of children with ID, parents also affect each others' more resilient adaptations in ways that have not been previously considered.

Parenting children with and without developmental delay: the role of self-mastery.

BACKGROUND: While parenting behaviours have direct effects on children's behavioural outcomes, other, more distal factors also may be shaping the way a mother handles parenting responsibilities. Dispositional factors are likely to be a major influence in determining how one parents. Although researchers have studied the relationships among maternal dispositional factors, parenting, and child behaviours, few studies have examined these relationships when the child is at developmental risk. Children with developmental delays evidence elevated clinical level behaviour problems, so this group is of primary interest in the search for precursors to psychopathology. The present study examined how the maternal dispositional trait of self-mastery, as well as supportive and non-supportive parenting, relate to behaviour problems in young children with and without developmental delay. METHOD: Participants were 225 families, drawn from Central Pennsylvania and Southern California. The children, all aged 4 years, were classified as delayed (n = 97) or non-delayed (n = 128). The Self-Mastery Scale measured perceived level of control over life events. The Coping with Children's Negative Emotions Scale measured different ways parents perceive themselves as reacting to their children's distress and negative affect. The Child Behavior Checklist assessed children's behaviour problems. RESULTS: Delayed condition mothers reported significantly more child behaviour problems than non-delayed condition mothers; the two conditions did not differ in self-mastery, supportive parenting, or non-supportive parenting. Self-mastery, non- supportive parenting reactions, and child behaviour problems all related significantly to one another. For the sample as a whole and within the delayed condition, the association between self-mastery and child behaviour problems was partially mediated by non-supportive parenting reactions, although self-mastery was still significantly associated with problem behaviour. In the non-delayed condition, although significant relationships also were found among the variables of interest, non-supportive parenting did not have a significant main or mediation effect. Delay status moderated the relationship between negative parenting reactions and child behaviour problems, assessed by the Child Behavior Checklist Total and Internalizing scores. When mothers displayed low levels of non-supportive reactions, children in the delayed and non-delayed groups had similar levels of total problem behaviour. However, when mothers were medium or high in non-supportive reactions, children in the delayed group had much higher levels of problem behaviours than those in the non-delayed group. CONCLUSIONS: The present study extended research on parental dispositional factors and parenting by measuring self-mastery as a global personality trait rather than measuring self-efficacy related specifically to childrearing. Moreover, relationships were examined for both developmentally delayed and non-delayed samples, allowing for a clearer understanding of the influences on problem behaviours in children with developmental delays. The findings support the view that parenting behaviours have a greater impact on children at developmental risk.

The transition to school: adaptation in young children with and without intellectual disability.

BACKGROUND: Previous research has highlighted the importance of the transition to school for young children and their families. A child's successful adaptation to school is likely influenced by a number of factors, including academic, social, emotional, behavioural and cognitive competencies. Children with intellectual disability (ID) may be at heightened risk for early school difficulties, in part due to their deficits in cognitive and adaptive behaviours. METHODS: Factors associated with the adaptive transition to school in young children with (n = 24) and without (n = 43) ID were examined. Adaptive transitions were defined as having few teacher-reported problem behaviours and positive student-teacher relationships. Child self-regulatory skills and both parent- and teacher-reported social skills were evaluated to determine if they predicted positive adaptation in school for 5- to 6-year-old children. Data were gathered from child assessments, parent reports on standardized measures, direct observations of delay of gratification tasks and teacher reports on standardized measures. RESULTS: Children with ID had significantly more teacher-reported problem behaviour, poorer overall student-teacher relationships, fewer parent- and teacher-reported social skills and fewer self-regulation skills than typically developing children. Self-regulation at child age 36 months (latency to touch a desired toy) was significantly related to adaptation to school, as were parent and teacher reports of social skills. Social skills significantly predicted adaptation to school, even after accounting for the effects of child IQ and adaptive behaviour. CONCLUSIONS: Children with ID had less positive early school experiences, as indicated by multiple indices of adaptation to school. Fostering early social skills may be an important target for increasing the positive adaptation to school for young children, especially those with ID.

Preschool children with intellectual disability: syndrome specificity, behaviour problems, and maternal well-being.

BACKGROUND: Children with intellectual disability (ID) are at heightened risk for behaviour problems and diagnosed mental disorder. Likewise, mothers of children with ID are more stressed than mothers of typically developing children. Research on behavioural phenotypes suggests that different syndromes of ID may be associated with distinct child behavioural risks and maternal well-being risks. In the present study, maternal reports of child behaviour problems and maternal well-being were examined for syndrome-specific differences. METHODS: The present authors studied the early manifestation and continuity of syndrome-specific behaviour problems in 215 preschool children belonging to 5 groups (typically developing, undifferentiated developmental delays, Down syndrome, autism, cerebral palsy) as well as the relation of syndrome group to maternal well-being. RESULTS: At age 3, children with autism and cerebral palsy showed the highest levels of behaviour problems, and children with Down syndrome and typically developing children showed the lowest levels. Mothers of children with autism reported more parenting stress than all other groups. These syndrome-specific patterns of behaviour and maternal stress were stable across ages 3, 4 and 5 years, except for relative increases in behaviour problems and maternal stress in the Down syndrome and cerebral palsy groups. Child syndrome contributed to maternal stress even after accounting for differences in behaviour problems and cognitive level. CONCLUSIONS: These results, although based on small syndrome groups, suggest that phenotypic expressions of behaviour problems are manifested as early as age 3. These behavioural differences were paralleled by differences in maternal stress, such that mothers of children with autism are at elevated risk for high stress. In addition, there appear to be other unexamined characteristics of these syndromes, beyond behaviour problems, which also contribute to maternal stress.

Preschool children with and without developmental delay: behaviour problems, parents' optimism and well-being.

BACKGROUND: Children with intellectual disability are at heightened risk for behaviour problems, and these are known to increase parenting stress. This study explored the relation of behaviour problems to less child-related domains of parent well-being (depression and marital adjustment), as well as the moderating effect of a personality trait, dispositional optimism. METHOD: Participating children (N = 214) were classified as developmentally delayed, borderline, or nondelayed. Mothers' and fathers' well-being and child behaviour problems were assessed at child ages 3 and 4 years. RESULTS: Parents of delayed and nondelayed preschoolers generally did not differ on depression or marital adjustment, but child behaviour problems were strongly related to scores on both measures. Optimism moderated this relationship, primarily for mothers. When child behaviour problems were high, mothers who were less optimistic reported lower scores on measures of well-being than did mothers who were more optimistic. CONCLUSIONS: Interventions for parents that aim to enhance both parenting skills and psychological well-being should be available in preschool. It may be beneficial for such programmes to focus not only on behaviour management strategies aimed at child behaviour change, but also on parents' belief systems, with the aim of increasing dispositional optimism.

Pre-school children with and without developmental delay: behaviour problems and parenting stress over time.

BACKGROUND: Children with intellectual disability are at heightened risk for behaviour problems and diagnosed mental disorder. METHODS: The present authors studied the early manifestation and continuity of problem behaviours in 205 pre-school children with and without developmental delays. RESULTS: Behaviour problems were quite stable over the year from age 36-48 months. Children with developmental delays were rated higher on behaviour problems than their non-delayed peers, and were three times as likely to score in the clinical range. Mothers and fathers showed high agreement in their rating of child problems, especially in the delayed group. Parenting stress was also higher in the delayed group, but was related to the extent of behaviour problems rather than to the child's developmental delay. CONCLUSIONS: Over time, a transactional model fit the relationship between parenting stress and behaviour problems: high parenting stress contributed to a worsening in child behaviour problems over time, and high child behaviour problems contributed to a worsening in parenting stress. Findings for mothers and fathers were quite similar.

Behaviour/mental health problems in young adults with intellectual disability: the impact on families.

BACKGROUND: The present authors studied the impact of dual diagnosis [i.e. intellectual disability (ID) and mental disorder] in young adults on their mothers' perceived levels of stress and decisions about placement. METHODS: The mothers of 103 young adults with severe ID were interviewed using a 2-3-h in-depth protocol of measures designed to assess their child's adaptive functioning, maladaptive behaviour, mental health problems and negative impact on the family, as well as their own thoughts on out-of-home placement. The Scales of Independent Behavior--Revised Problem Behavior Scale assessed problem behaviours and the Reiss Screen assessed mental disorder. RESULTS: These measures were highly correlated (r = 0.64), but tapped some different domains of maladaptive behaviour and proved to be most predictive when employed together. Behaviour and/or mental health (B/MH) problems significantly predicted the mothers' perceived negative impact of the young adult on the family, even after controlling for other young adult characteristics. These problems also predicted the family's steps toward seeking out-of-home placement, as did better young adult health and the mother's higher educational attainment; stress did not predict additional variance in placement once these variables were accounted for. CONCLUSIONS: The discussion focuses on the implications for service provision to families of young adults with B/MH problems.

Stepping aside for elderly persons in American versus east-Asian cultures.

In the current study, younger (15-30 years of age) and older (60+ years of age) Asian-American and European-American individuals (N = 160) were observed as they approached someone of the same ethnic group on a walkway at a city market. The interaction was recorded if one stepped aside and let the other pass. Younger Asian-Americans tended to step aside for older Asian-Americans. No such trend was observed among European-Americans. Results were discussed in terms of cultural values.

Expressed emotion, parenting stress, and adjustment in mothers of young children with behavior problems.

Expressed Emotion (EE), a measure of the emotional climate of the family, predicts subsequent adjustment of adults with mental disorder (Leff & Vaughn, 1985). Despite the acknowledged importance of the family in childhood disorders, there have been relatively few studies of expressed emotion with adolescents and school-aged children and virtually none focused on preschoolers. The present study utilized the Five Minute Speech Sample (FMSS) to examine how Expressed Emotion relates concurrently and longitudinally to child problem status in a community sample of 112 preschool-aged children. At preschool, the proportion of high EE increased significantly across three child groups: Comparison (8.1%), Borderline Problem (15.8%), and High Problem (41.2%); however, preschool EE was not predictive of subsequent child status at 1st grade. Expanded FMSS codes. tapping positive affect and worry about the child, were also related to child problem group at preschool and were predictive of subsequent child status at 1st grade. Because parents' stress and adjustment were also highly related to child problem group status, we examined whether the FMSS codes were essentially a proxy for these or whether they explained unique variance. In two stepwise regressions on preschool child group status (divided by total problems and by externalizing problems), maternal stress was the only variable to enter. Also, in predicting to 1st grade externalizing child group status, only maternal stress entered. Discussion focused on the extension of the EE construct and other FMSS coding to young children, and the need to recognize that to some extent these variables may reflect maternal stress and adjustment.

Dexamethasone inhibits insulin-like growth factor signaling and potentiates myoblast apoptosis.

In the critically ill, glucocorticoids induce myopathy, combining profound protein catabolism and mild myotubular death. Insulin-like growth factors (IGFs) inhibit muscle catabolism through activation of phosphatidylinositol 3-kinase (PI3K). Using rat L6 myoblasts, we show that IGF-I also acts through PI3K to inhibit apoptosis induced by hyperosmolar metabolic stress with 300 mM mannitol. We find that the glucocorticoid dexamethasone inhibits this antiapoptotic effect of IGF-I by impairing PI3K signaling. Dexamethasone induces overexpression of the PI3K subunit p85alpha, which, in turn, competes with the complete PI3K heterodimer for binding at insulin receptor substrate-1, inhibiting PI3K activation. Dexamethasone blocks IGF-I-induced phosphorylation of Akt, a PI3K-dependent process. Increased cellular p85alpha abundance, induced by either 10 microM dexamethasone or transient transfection with a plasmid coding for p85alpha, significantly inhibits IGF-I rescue from apoptosis induced by mannitol, as indicated by both loss of cell viability and increased activity of caspase-3 by fluorogenic assay. Conversely, constitutively active PI3K inhibits death induced by mannitol, even in the presence of dexamethasone. These findings may have particular relevance in the pathogenesis of acute steroid myopathy in critical illness, in which catabolic glucocorticoid effects combine with acute metabolic stressors, including sepsis, fasting, and chemical denervation.