Correlates of insight in first episode psychosis

Impaired insight is common in schizophrenia and may be related to poor treatment adherence. Few studies have examined the clinical and neurocognitive correlates of insight in early schizophrenia. Early course schizophrenia, schizoaffective, and schizophreniform disorder patients (n=535) were studied. The Positive and Negative Symptom Scale (PANSS) was used to assess psychopathology, and a broad range of neuropsychological functions was assessed. Using hierarchical stepwise multiple regression analyses, we examined the association of clinical, neurocognitive, and premorbid measures with the level of insight. Impaired insight was associated with overall symptomatology, including positive, negative, and general psychopathology and with deficits in cognitive functioning. In descending order of robustness, the significant variables were PANSS general psychopathology (p<0.0001), Rey Auditory Verbal Learning Test (p<0.0004), Clinical Global Impression (p<0.005), PANSS positive (p<0.007), and premorbid adjustment—general subscale (p=0.02). Among the PANSS general psychopathology items, unusual thought content was most robustly associated with impaired insight (p<0.00000). Insight impairment is very common in early schizophrenia, and appears to be associated with a broad range of psychopathology and deficits in multiple cognitive domains. These observations suggest that deficits in insight may be related to a generalized dysfunction of neural networks involved in memory, learning, and executive functions.     

Correlates of victimisation amongst people with psychosis

Abstract. Background: While much attention has been given to the prediction of violent offending behaviour amongst people with psychotic disorders, less attention has been given to the fact that these same individuals are often the victims of violence. In this paper, we examine victimisation amongst participants in a prevalence study of psychosis, and describe demographic and clinical correlates of victimisation. Method: The study was based on the Australian National Survey of Mental Health and Wellbeing—Low Prevalence (Psychotic) Disorders. The participants were asked if they had been a victim of violence in the previous year. The association between selected demographic and clinical variables and being a victim of violence was examined using logistic regression. Results: Of the 962 individuals with psychosis, 172 reported being a victim of violence in the past 12 months (17.9 %). The odds of being a victim were increased in those who: (a) were female, (b) were homeless, (c) had a lifetime history of substance abuse, (d) had been arrested in the previous 12 months, (e) had poorer social and occupational function, and (f) had higher scores on the disorganisation summary score. Conclusions: Clinicians should remain mindful that one out of every six individuals with a psychotic disorder reports being a victim of violence in the previous year. Models of care that address issues related to symptom relief, accommodation, and exposure to high-crime areas may reduce the rates of victimisation amongst those with psychotic disorders.     

Food deprivation after treatment blocks the multiple-day hyperphagic response to SHU9119 administration

The multiple-day hyperphagic effect of the melanocortin 3/4 receptor antagonist, SHU9119, is apparently abolished when rats are food-deprived for 24 h after central (4th-ventricular) injection. Here, we affirmed this indication, and addressed the possibility that the orexigenic potency of SHU9119 is simply masked by the refeeding hyperphagia that follows food deprivation. This explanation is discounted by our finding that the drug response in ad libitum-fed rats and the deprivation response are expressed at different, and non-overlapping, times of day. We then asked whether food consumption during a hypothesized critical period in the hours after treatment is necessary for expression of the hyperphagic response to SHU9119, or alternatively, whether blood-borne signals that emerge only after an extended period of food restriction underlie the drug-state interaction. Evidence favoring the latter interpretation was derived from a series of four experiments over which the timing and duration of food access after drug administration was varied. The results indicate an interaction between melanocortin receptor activity and the metabolic state of the animal, and constrain our thinking about the peripheral signals and central mechanisms that underlie this interaction.     

Paracingulate asymmetry in anterior and midcingulate cortex: sex differences and the effect of measurement technique

Many structural brain asymmetries accompany left hemisphere language dominance. For example, the cingulate sulcus is larger in the medial cortex of the right hemisphere, while the more dorsal paracingulate sulcus is larger on the left. The functional significance of these asymmetries is unknown because fMRI studies rarely attempt to localize activation to specific sulci, possibly due to difficulties in consistent sulcal identification. In medial cortex, for example, there are many regions of partial sulcal overlap where MRI images do not provide sufficient information to unambiguously distinguish a paracingulate sulcus from a displaced anterior cingulate segment. As large samples of postmortem material are rarely available for cytoarchitectural studies of sulcal variation, we have investigated the effect of variation in boundary and sulcal definition on paracingulate asymmetry in the MRI scans of 200 healthy adults (100 men, 100 women). Although women displayed a reliable asymmetry in the size of the paracingulate sulcus, regardless of boundary definition or technique, asymmetry was greatest when (1) the measurement was limited to the midcingulate region between the genu and the anterior commissure; and (2) the more dorsal of two overlapping sulci was always classified as a paracingulate sulcus (rather than as a displaced cingulate segment). The fact that paracingulate asymmetry is maximal in the midcingulate region suggests that this region may play a particular role in hemispheric specialization for language. Future work should investigate the structural and functional correlates of sulcal variation in this region.     

Alkaline Isomerization of Ferricytochrome c: Identification of the Lysine Ligand

Changes in the visible absorbance spectra of complexes of horse heart cytochrome c hemopeptide 1-65, peptide 66-104, and their guanidinated counterparts are compared with those characteristic of native and fully guanidinated ferricytochrome c over the pH range 7 to 11. Upon raising the pH, the methionine ligand in the guanidinated hemopeptide 1-65.peptide 66-104 complex is replaced by a strong field ligand. By contrast, the methionine ligand in the hemopeptide 1-65.guanidinated peptide 66-104 is replaced by a weak field ligand. These results demonstrate that lysine 13 does not ligate with the heme iron upon isomerization of ferricytochrome c and that the ligand in the horse heart protein is one of the eight lysine residues in the 66-104 segment of the polypeptide, most likely lysine 79.     

Objective and subjective social class gradients for substance use among Mexican adolescents

This study examines the shape of social class gradients for substance use among Mexican adolescents. Substance use and objective and subjective indicators of social class were assessed in house-to-house surveys conducted with 7614 Mexican adolescents in 2004. The sample was designed to be representative of the poorest urban communities in seven Mexican states. The prevalence of current smoking was 16.8%, alcohol consumption was 30.2%, and drug use was 4.6%. Multiple logistic regressions are used to estimate the associations of objective indicators of socioeconomic status (SES) and subjective social status (SSS)—at both community and societal levels–and smoking, alcohol and drug use. Adolescents who perceived themselves as higher in social status in reference to their local community reported more smoking and drinking. Our findings were similar when we used objective measures of SES, such as maternal education and total monthly household expenditures per person. In contrast, adolescents who perceived that they had high social standing in reference to Mexican society as a whole were less likely to report being current smokers and drinkers. We found no significant association between social status and drug use. Research into how adolescents perceive themselves in reference to their peer communities may help strengthen programs and policies aimed at promoting health in vulnerable adolescent populations.     

Facial emotion recognition in agenesis of the corpus callosum

Background

Impaired social functioning is a common symptom of individuals with developmental disruptions in callosal connectivity. Among these developmental conditions, agenesis of the corpus callosum provides the most extreme and clearly identifiable example of callosal disconnection. To date, deficits in nonliteral language comprehension, humor, theory of mind, and social reasoning have been documented in agenesis of the corpus callosum. Here, we examined a basic social ability as yet not investigated in this population: recognition of facial emotion and its association with social gaze.

Methods

Nine individuals with callosal agenesis and nine matched controls completed four tasks involving emotional faces: emotion recognition from upright and inverted faces, gender recognition, and passive viewing. Eye-tracking data were collected concurrently on all four tasks and analyzed according to designated facial regions of interest.

Results

Individuals with callosal agenesis exhibited impairments in recognizing emotions from upright faces, in particular lower accuracy for fear and anger, and these impairments were directly associated with diminished attention to the eye region. The callosal agenesis group exhibited greater consistency in emotion recognition across conditions (upright vs. inverted), with poorest performance for fear identification in both conditions. The callosal agenesis group also had atypical facial scanning (lower fractional dwell time in the eye region) during gender naming and passive viewing of faces, but they did not differ from controls on gender naming performance. The pattern of results did not differ when taking into account full-scale intelligence quotient or presence of autism spectrum symptoms.

Conclusions

Agenesis of the corpus callosum results in a pattern of atypical facial scanning characterized by diminished attention to the eyes. This pattern suggests that reduced callosal connectivity may contribute to the development and maintenance of emotion processing deficits involving reduced attention to others'' eyes.     

Normalization of GABAA receptor specific binding in the substantia nigra reticulata and the prevention of L-dopa-induced dyskinesias in MPTP parkinsonian monkeys

L-Dopa therapy in Parkinson's disease (PD) is counfounded by the development of involuntary movements such as L-Dopa-induced dyskinesias (LIDs). In this study GABA(A) receptor autoradiography was assessed using [(3)H]flunitrazepam binding to the benzodiazepine site of the GABA(A) receptor and [(35)S]t-butylbicyclophosphorothionate (TBPS) binding to the chloride channel of GABA(A) receptors in the substantia nigra reticulata (SNr) and subthalamic nucleus (STN). L-Dopa-treated parkinsonian monkeys experiencing LIDs were compared to animals in which LIDs was prevented by adjunct treatments with CI-1041, a selective antagonist of the NR1A/2B subtype of NMDA receptor, or low doses of the dopamine D2 receptor agonist, cabergoline. Our results demonstrated a decrease of GABA(A) receptor specific binding in the posterior part of the SNr in dyskinetic monkeys compared to nondyskinetic animals, while no modulation has been observed in the STN. These results provide evidence for the first time that pharmacological treatments preventing LIDs in nonhuman primate model of PD are associated with normalization of GABA(A) receptor-mediated signalling in the SNr.