Language and executive functioning in young adults with Down syndrome.

BACKGROUND: This study examined the association between executive functioning and language in young adults with Down syndrome (DS). METHOD: Nineteen young adults with DS (aged 19-24 years) completed standardised measures of overall cognition, vocabulary, verbal fluency and executive function skills. RESULTS: Friedman's analysis of variance (χ2 (3) = 28.15, P < .001) and post hoc comparisons indicated that, on average, participants had a significantly lower overall non-verbal than verbal cognitive age equivalent and lower expressive than receptive vocabulary skills. Using Spearman correlations, performance on a verbal measure of cognition inhibition was significantly negatively related to receptive vocabulary (ρ = -.529, adjusted P = .036) and verbal fluency (ρ = -.608, adjusted P = .022). Attention was significantly positively correlated with receptive (ρ = .698, adjusted-p = .005) and expressive (ρ = .542, adjusted P = .027) vocabulary. Verbal working memory was significantly positively associated with receptive vocabulary (ρ = .585, adjusted P = .022) and verbal fluency (ρ = .737, adjusted P = .003). Finally, visuospatial working memory was significantly associated with receptive vocabulary (ρ = .562, adjusted P = .027). CONCLUSIONS: Verbal and non-verbal measures of executive functioning skills had important associations with language ability in young adults with DS. Future translational research is needed to investigate causal pathways underlying these relationships. Research should explore if interventions aimed at increasing executive functioning skills (e.g. attention, inhibition and working memory) have the potential to lead to increases in language for young adults with DS.

Parental attributions for positive behaviours in children with autism spectrum disorder.

BACKGROUND: The present study examined parental attributions for positive child behaviour in children with Autism Spectrum Disorder (ASD) and their association with parent outcomes. METHOD: In total, 175 couples who had a child with ASD (5-12 years) completed measures about the child's positive behaviour, ASD symptoms, functional skills and negative behaviour problems, and their own positive and negative affect and closeness in the parent-child relationship. A comparison group of 170 couples who had a child without a neurodevelopmental disability also completed measures. RESULTS: Dyadic multilevel models were conducted. Parents of children with ASD believed that their child's positive behaviour was due to factors less internal to the child, less stable and less controllable by the child than the comparison group. Beliefs about stability were associated with closeness in the parent-child relationship. Child age and level of impairment and parent education were associated with parental attributions. CONCLUSIONS: Interventions that alter parental attributions may offer pathways to increase closeness in the parent-child relationship.

Self-reported versus informant-reported depressive symptoms in adults with mild intellectual disability.

BACKGROUND: Virtually nothing is known about potential differences in the types of depression symptoms reported by adults with mild intellectual disability (ID) on self-reported questionnaires as compared with the types of symptoms reported by caregivers on informant questionnaires. Moreover, little is known about how the presentation of depression among adults with mild ID varies based on socio-demographic characteristics. METHODS: We compared findings from two self-reported questionnaires, the Self-Reported Depression Questionnaire (SRDQ) and the Glasgow Depression Scale for People with a Learning Disability (GDS), to that of an informant questionnaire of depressive symptoms, the Glasgow Depression Scale--Caregiver Supplement (CGDS), in 80 adults with mild ID. We also examined the association between age, sex, IQ and the presence of a co-occurring psychiatric disorder and frequency of affective, cognitive and somatic depressive symptoms in our sample of adults with mild ID. RESULTS: Adults with mild ID self-reported a higher frequency of affective and cognitive depressive symptoms than staff reported on the informant measure. Staff reported a higher frequency of somatic symptoms than adults with mild ID on one of the self-reported questionnaires (GDS) and a similar frequency on the other self-reported questionnaire (SRDQ). Important differences were found in the types of depressive symptoms based on their IQ, age and presence of a co-occurring psychiatric disorder. CONCLUSION: Informant questionnaires offer valuable information, but assessment should include self-reported questionnaires as these questionnaires add unique information about internalised experiences (affective and cognitive symptoms) of adults with mild ID that may not be apparent to caregivers. Health care providers should be made aware of the important differences in the presentation of depressive based on their IQ, age and presence of a co-occurring psychiatric disorder.

Combined caffeine and bright light reduces dangerous driving in sleep-deprived healthy volunteers: a pilot cross-over randomised controlled trial.

AIM OF THE STUDY: To explore the effects of caffeine and bright light therapy on simulated nighttime driving in sleep-deprived healthy volunteers. PARTICIPANTS AND METHODS: Twelve male healthy volunteers aged 20 to 50 years participated in a randomized cross-over study of simulated nighttime driving at a sleep laboratory, followed by recovery sleep with polysomnography at home. The volunteers received variable combinations of caffeine 200mg (C+), caffeine placebo (C-), bright light 10,000 lux (L+), and bright light placebo<50 lux (L-), in four sessions (C+L+, C+L-, C-L+, C-L-), in random order with a wash-out period of 7 days. Treatments were given at 1 a.m. and testing was performed at 1:30 a.m., 3 a.m., 4 a.m., and 6 a.m. Lane drifting was the primary outcome measure. Other measures were reaction times, self-rated fatigue, sleepiness and recovery sleep. RESULTS: Without treatment, lane drifting increased throughout the night, and objective and subjective vigilance declined. Paired comparisons showed that lane drifting was significantly worse at 6 a.m. and at 4 a.m. than at 1:30 a.m. There was a global treatment effect on lane drifting. Lane drifting at 6 a.m. was significantly decreased with C+L+ compared to C-L-. CONCLUSIONS: Bright light therapy combined with caffeine administered at 1 a.m. decreased lane drifting by healthy volunteers during simulated nighttime driving.

Reassurance seeking and depression in adults with mild intellectual disability.

BACKGROUND: Adults with intellectual disability (ID) experience a high prevalence of depression. Yet, little research has investigated interpersonal processes related to depression in this population. In the general population, depressed persons behave in ways that elicit negative and rejecting reactions from others. In particular, excessive reassurance seeking, defined as excessively and persistently seeking assurance from others that one is lovable and worthy, indirectly contributes to depressive symptoms through evoking negative and rejecting social interactions. We examined the relation between excessive reassurance seeking, negative and rejecting social interactions and depression in adults with mild ID. METHOD: Eighty-seven adults with mild ID and staff completed the Glasgow Depression Scale for people with a Learning Disorder and the Reassurance-Seeking Scale. In addition, adults with mild ID reported on their experience of negative social interactions, and staff rated their relative preference to interact with the adult with mild ID. A meditational model of the indirect effect of excessive reassurance seeking on depressive symptoms via negative and rejecting social interactions was tested. RESULTS: Excessive reassurance seeking was positively related to depressive symptoms. Negative and rejecting interactions partially mediated the relation between excessive reassurance seeking and depressive symptoms. CONCLUSIONS: Findings identify an important interpersonal process in depression. Efforts to educate staff and adults with mild ID about excessive reassurance seeking and ways to alter it may be useful in treating depression.

Prevalence and risk factors of maladaptive behaviour in young children with Autistic Disorder.

BACKGROUND: Children with Autistic Disorder (AD) evidence more co-occurring maladaptive behaviours than their typically developing peers and peers with intellectual disability because of other aetiologies. The present study investigated the prevalence of Clinically Significant maladaptive behaviours during early childhood and identified at-risk subgroups of young children with AD. METHOD: Parents rated their child's maladaptive behaviours on the Child Behaviour Checklist (CBCL) in 169 children with AD aged 1.5 to 5.8 years. RESULTS: One-third of young children with AD had a CBCL Total Problems score in the Clinically Significant range. The highest percentage of Clinically Significant scores were in the Withdrawal, Attention, and Aggression CBCL syndrome scales. There was a high degree of co-morbidity of Clinically Significant maladaptive behaviours. Several subject characteristic risk factors for maladaptive behaviours were identified. CONCLUSIONS: Findings highlight the need to include behavioural management strategies aimed at increasing social engagement, sustained attention and decreasing aggressive behaviour in comprehensive intervention programmes for young children with AD.

A review of the reliability and validity of Likert-type scales for people with intellectual disability.

BACKGROUND: Likert-type scales are increasingly being used among people with intellectual disability (ID). These scales offer an efficient method for capturing a wide range of variance in self-reported attitudes and behaviours. This review is an attempt to evaluate the reliability and validity of Likert-type scales in people with ID. METHODS: Fifty-one studies reporting response rates, response bias, reliability and validity of Likert-type scales among adolescents and adults with ID were reviewed. RESULTS: Low response rates were found among adolescents and adults with moderate to profound ID, when pictorial representations of response alternatives were not employed, and for Likert-type scales with self-descriptive statements. Response bias was evident, particularly among adolescents and adults with moderate to profound ID. Likert-type scales have better reliability and validity among adolescents and adults with borderline IQ or mild ID. Pretests and clarifying questions increase reliability and validity. CONCLUSIONS: Likert-type scales should include pictorial representations of response alternatives, a single set of one or two word response descriptors, clarifying questions, and pretests, and are best used with adolescents and adults with borderline IQ to mild ID.

Modulation of ceroid accumulation in macrophages in vitro.

Mouse resident peritoneal macrophages (MPM) cultured with artificial lipoprotein consisting of cholesteryl linoleate complexed with bovine serum albumin (CL/BSA) rapidly accumulate ceroid in the form of rings. Experiments with various phenolic radical scavenger antioxidants and derivatives showed that the radical scavengers which are strongly lipophilic, and possess a free (i.e. non-esterified) phenolic hydroxyl group are inhibitors of ceroid ring formation. Time-course experiments with MPM and CL/BSA in which either or both of the components of the artificial lipoprotein have been oxidised before feeding showed that such oxidation accelerated ceroid accumulation, and suggested that oxidation of the lipoprotein is rate-determining in ceroid accumulation. Copper appeared to be a good catalyst for this. Agents able to activate the respiratory burst production of reactive oxygen species appeared to have no accelerating effect on ceroid accumulation from CL/BSA by MPM in a time-course. A novel method has been attempted for quantitating ceroid in MPM by means of its autofluorescence, using a Fluorescence-activated Cell Sorter (FACS). The results from FACS agree qualitatively with those from alcohol-xylene treatment followed by oil-red-o staining (AX/ORO). MPM cultured with CL/BSA for up to 4 days showed a 2.7-4.6-fold increase in mean fluorescence (at wavelengths greater than 490 nm) over MPM cultured with cholesteryl oleate/BSA (CO/BSA), with CL/BSA/butylated hydroxytoluene (CL/BSA/BHT), with CL/BSA/probucol, and with no artificial lipoprotein. The implications of the findings with respect to human atherosclerosis are discussed.

Ceroid accumulation by murine peritoneal macrophages exposed to artificial lipoproteins.

Murine resident peritoneal macrophages were maintained in cell culture in a medium containing 10% lipoprotein-deficient fetal calf serum to which various artificial lipoproteins (lipid-bovine serum albumin complexes) had been added. Ceroid accumulated in cells exposed to artificial lipoproteins containing cholesteryl esters or acylglycerols possessing polyunsaturated fatty acid residues, but not in cells exposed to lipoproteins containing less readily oxidized lipids. Oxidation of cholesteryl linoleate before its incorporation into artificial lipoprotein accelerated ceroid production. Incorporation of free radical scavengers into cholesteryl linoleate-containing artificial lipoproteins impaired ceroid formation. The results are discussed in terms of the mechanisms by which the ceroid might have been produced and its significance for human atherogenesis.