108 research outputs found
The impact of phenylalanine levels on cognitive outcomes in adults with phenylketonuria:effects across tasks and developmental stages
OBJECTIVE: Phenylketonuria (PKU) is due to an inability to metabolize the amino acid phenylalanine (Phe), leading to its accumulation in the brain. Phe levels can be controlled following a protein-free diet, but cognitive impairments are still present. A number of questions remain to be answered related to which type of metabolic control is important, the age when it is important, the cognitive functions which are most affected and, the best tests to use to monitor cognitive health. METHOD: We investigated the impact of metabolic control at different ages on cognitive performance in 37 early treated adults with PKU. RESULTS: (a) Phe variation was as associated to performance as average Phe showing that stable dietary control is as important as strict control; (b) For some tasks, current and adult Phe were stronger predictors of performance than childhood or adolescent Phe, showing the importance of a strict diet even in adulthood; and (c) The relationship between performance and Phe levels varied depending on time and cognitive domain. For some functions (sustained attention, visuomotor coordination), Phe at the time of testing was the best predictor. While for other functions (visual attention, executive functions) there was a diminishing or stable relationship across time. CONCLUSION: Results show the importance of selecting the right tasks to monitor outcomes across ages, but also that the impact of bio-chemical disruptions is different for different functions, at different ages. We show how inherited metabolic diseases offer us a unique vantage point to inform our understanding of brain development and functioning. (PsycINFO Database Recor
Cognitive outcomes in early-treated adults with phenylketonuria (PKU):a comprehensive picture across domains
OBJECTIVE: Phenylketonuria (PKU) is an inherited metabolic disease which affects cognitive functions due to an inability to metabolize phenylalanine which leads to the accumulation of toxic by-products (Phe) in the brain. PKU can be effectively treated with a low phenylalanine diet, but some cognitive deficits remain. Studies have reported impairments, especially for processing speed and executive functions, but there is a lack of comprehensive assessment across cognitive domains. Moreover, it is important to establish outcomes in early treated adults with PKU (AwPKU) who have better metabolic control than groups previously reported in the literature. METHOD: We tested 37 AwPKU with an unprecedented number of tasks (N = 28) and measures (N = 44) and compared results with 30 controls matched for age and education. RESULTS: We found (a) group impairments, particularly in tasks tapping speed of processing and complex executive functions; (b) high variability across participants, with a sizable number of AwPKU with completely normal performance (about 38%); (c) but also a sizable number of participants who were clearly impaired (about 24%); and (d) good performance in tasks tapping verbal learning, verbal memory and orthographic processing, indicating no generalized learning impairment. CONCLUSION: Our results indicate good outcomes, but also that deficits are still present with current treatment policies. (PsycINFO Database Recor
Burnout and engagement in fourth-year social work students : why we should be concerned
This article focuses on levels of burnout as well as engagement experienced by fourth-year undergraduate social work students attending a South African university. By means of quantitative procedures, data were obtained from 43 final-year social work students who completed a self-administered questionnaire. Respondents presented with above-average levels of exhaustion, professional efficacy, vigour, dedication and absorption, and below average levels of cynicism. Non-parametric procedures revealed significant differences in the levels of burnout related to population group, place of origin and household income status. Recommendations focus on monitoring the wellbeing of students and mobilising support for students who appear more vulnerable to burnout and low academic engagement
Impairment in acquisition of conditioned fear in schizophrenia
Individuals with schizophrenia show impairments in associative learning. One well-studied, quantifiable form of associative learning is Pavlovian fear conditioning. However, to date, studies of fear conditioning in schizophrenia have been inconclusive, possibly because they lacked sufficient power. To address this issue, we pooled data from four independent fear conditioning studies that included a total of 77 individuals with schizophrenia and 74 control subjects. Skin conductance responses (SCRs) to stimuli that were paired (the CS + ) or not paired (CS−) with an aversive, unconditioned stimulus were measured, and the success of acquisition of differential conditioning (the magnitude of CS + vs. CS− SCRs) and responses to CS + and CS− separately were assessed. We found that acquisition of differential conditioned fear responses was significantly lower in individuals with schizophrenia than in healthy controls (Cohen’s d = 0.53). This effect was primarily related to a significantly higher response to the CS− stimulus in the schizophrenia compared to the control group. Moreover, the magnitude of this response to the CS− in the schizophrenia group was correlated with the severity of delusional ideation (p = 0.006). Other symptoms or antipsychotic dose were not associated with fear conditioning measures. In conclusion, individuals with schizophrenia who endorse delusional beliefs may be over-responsive to neutral stimuli during fear conditioning. This finding is consistent with prior models of abnormal associative learning in psychosis
Internet use among university students: A reason for concern?
International studies reveal that students have more freedom, as well as unstructured and unsupervised time, which makes them susceptible to problematic internet use (PIU). Although students are a risk group for PIU, no evidence of local research on internet use among students could be identified. This article reports on a study on the nature and impact of internet use among students at a tertiary institution. A quantitative research approach was adopted and a survey with a group-administered questionnaire was conducted with 295 second-year students (between 18 and 25 years) registered for a module in a basic social science. Respondents were recruited through convenience sampling. The nature of internet use was explored with reference to internet platforms, reasons for internet use, devices for connecting to the internet, and the locations where respondents access the internet. The impact of internet use was explored through eight constructs adopted from two screening instruments in the public domain, i.e. the Internet-Related Addictive Behaviour Inventory and the Problematic Internet Use Questionnaire. The research results were calculated by means of descriptive and association statistics, specifically the chi-square and Fisher’s exact tests. Ethical considerations, such as informed consent and voluntary participation, were observed. The research results revealed that the respondents preferred email and chatting as internet platforms, while they used the internet mostly for extrinsic reasons, such as for assignments and socialising. Online activities occurred mostly on campus and at home during the early evenings via mobile phones or laptops. The respondents scored relatively low on the constructs measuring PIU. However, two constructs ‘escape from problems’ and ‘loss of control’ presented with markedly higher scores and could be flagged as potential risk areas. Furthermore, association statistics indicated a statistically significant difference of some constructs with regard to gender and the romantic relationship status of respondents, which could be considered in the provision of student support services. The development and evaluation of evidence-based interventions for the prevention, treatment and management of PIU are recommended
A developmental social work perspective on problematic Internet use among university students
Problematic internet use (PIU) is a growing phenomenon worldwide. Students
in higher education especially are a vulnerable group for developing
symptoms associated with PIU as a result of the idiosyncratic characteristics of
student life. Owing to a lacuna in local social work research on the nature,
extent and impact of internet use among students in South Africa, a crosssectional survey was conducted with 498 (n = 498) second-year undergraduate
students at a South African university. The results indicate that students access
the internet on university campuses and at home daily through their cell
phones and laptops for academic and social purposes. Although the average
number of hours spent on the internet per day does not indicate PIU, the
findings flag certain symptoms associated with PIU, for example, tolerance,
escape from problems, and loss of control. Social workers should not be
complacent, but rather introduce services to lower students’ risk of PIU.
Considering the country’s adoption of social development as welfare model,
developmental social work services on the preventive, early intervention and
treatment levels as well as policy development are recommended.https://upjournals.co.za/index.php/SWPR/index2020-12-01pm2020Social Work and Criminolog
Dissociation of brain activation in autism and schizotypal personality disorder during social judgements
Background
There are overlaps between autism and schizophrenia but these are particularly pronounced, especially in social domains, for higher functioning individuals with autism spectrum disorders (ASD) or schizotypal personality disorder (SPD). It is not known whether these overlapping social deficits result from shared or distinct brain mechanisms. We therefore compared social cognition in ASD and SPD using functional magnetic resonance imaging (fMRI).
Methods
Twenty-one individuals with SPD, 28 with ASD and 33 controls were compared with respect to clinical symptoms using the Positive and Negative Syndrome Scale; social cognition, using a social judgment task and Ekman 60 faces task; and brain activation using an fMRI task of social judgment.
Results
The ASD and SPD groups showed few differences in symptoms or social cognition. However, fMRI showed that, compared to ASD, the SPD group showed significantly greater activation during social compared to gender judgments in the amygdala and 3 clusters: right posterior cerebellum, extending into fusiform and inferior temporal gyri; left posterior cerebellum; and left intraparietal sulcus extending through medial portions of the temporal gyri into the fusiform gyrus (all P < .05 family-wise error corrected). Control activations lay between the ASD and SPD groups.
Conclusions
Although social cognitive deficits in ASD and SPD appear superficially similar they are the result of different brain mechanisms. These findings have implications for therapeutic interventions targeted at social dysfunction in these conditions
Overactivation of fear systems to neutral faces in schizophrenia
Background The amygdala plays a central role in detecting and responding to fear-related stimuli. A number of recent studies have reported decreased amygdala activation in schizophrenia to emotional stimuli (such as fearful faces) compared with matched neutral stimuli (such as neutral faces). We investigated whether the apparent decrease in amygdala activation in schizophrenia could actually derive from increased amygdala activation to the neutral comparator stimuli. Methods Nineteen patients with schizophrenia and 24 matched control participants viewed pictures of faces with either fearful or neutral facial expressions, and a baseline condition, during functional magnetic resonance imaging scanning. Results Patients with schizophrenia showed a relative decrease in amygdala activation to fearful faces compared with neutral faces. However, this difference resulted from an increase in amygdala activation to the neutral faces in patients with schizophrenia, not from a decreased response to the fearful faces. Conclusions Patients with schizophrenia show an increased response of the amygdala to neutral faces. This is sufficient to explain their apparent deficit in amygdala activation to fearful faces compared with neutral faces. The inappropriate activation of neural systems involved in fear to otherwise neutral stimuli may contribute to the development of psychotic symptoms in schizophrenia
Prediction of depression in individuals at high familial risk of mood disorders using functional magnetic resonance imaging [Article]
Objective Bipolar disorder is a highly heritable condition. First-degree relatives of affected individuals have a more than a ten-fold increased risk of developing bipolar disorder (BD), and a three-fold risk of developing major depressive disorder (MDD) than the general population. It is unclear however whether differences in brain activation reported in BD and MDD are present before the onset of illness. Methods We studied 98 young unaffected individuals at high familial risk of BD and 58 healthy controls using functional Magnetic Resonance Imaging (fMRI) scans and a task involving executive and language processing. Twenty of the high-risk subjects subsequently developed MDD after the baseline fMRI scan. Results At baseline the high-risk subjects who later developed MDD demonstrated relatively increased activation in the insula cortex, compared to controls and high risk subjects who remained well. In the healthy controls and high-risk group who remained well, this region demonstrated reduced engagement with increasing task difficulty. The high risk subjects who subsequently developed MDD did not demonstrate this normal disengagement. Activation in this region correlated positively with measures of cyclothymia and neuroticism at baseline, but not with measures of depression. Conclusions These results suggest that increased activation of the insula can differentiate individuals at high-risk of bipolar disorder who later develop MDD from healthy controls and those at familial risk who remain well. These findings offer the potential of future risk stratification in individuals at risk of mood disorder for familial reasons
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