Eating psychopathology and psychosocial impairment in patients treated at a Singapore eating disorders treatment programme.

INTRODUCTION: There is limited data on the psychopathology of eating disorders in Singapore. This study: (a) described levels of eating psychopathology and psychosocial impairment among individuals diagnosed with eating disorders at our hospital; and (b) compared the related psychopathology of these patients. METHODS: Between 1 August 2010 and 31 July 2012, 257 individuals who met the diagnostic criteria for eating disorders completed the Eating Disorder Examination Questionnaire (EDE-Q) and Clinical Impairment Assessment questionnaire (CIA). RESULTS: A majority of participants were women and of Chinese ethnicity. Diagnoses included anorexia nervosa (AN; 41.6%), bulimia nervosa (BN; 29.6%) and eating disorder not otherwise specified (EDNOS; 28.8%). Mean age at presentation was 20.52 ± 7.14 years and mean body mass index was 17.84 ± 4.18 kg/m2. Individuals with AN were significantly younger at presentation and had shorter duration of untreated illness compared to those with BN and EDNOS. There were no significant differences in the CIA scores of the diagnostic groups. Participants with BN scored higher in all subscales of the EDE-Q than those with AN and EDNOS. Our sample scored lower in most subscales of EDE-Q when compared to treatment centres in Sweden, Australia and the United States. CONCLUSION: Our clinical sample reported lower scores of psychopathology compared to overseas centres. This could be attributed to the higher percentages of BN and EDNOS diagnosed in overseas populations. Individuals with AN showed higher levels of psychopathology in our study compared to patients from the United States.

Meta-analytic review of the effects of a single dose of intranasal oxytocin on threat processing in humans.

BACKGROUND: Heightened threat sensitivity is a transdiagnostic feature in several psychiatric disorders. The neuropeptide oxytocin has been shown to reduce fear related behaviours and facilitated fear extinction in animals. These findings have led to increasing interest to explore the effects of intranasal oxytocin on threat processing in humans. METHODS: The review included 26 studies (N = 1173), nine of which included clinical populations (N = 234). The clinical groups included were people with borderline personality disorder (BPD), anorexia nervosa, bulimia nervosa, depression, anxiety, and alcohol dependence disorder. We examined the effects of a single dose of intranasal oxytocin on startle response, attentional responses, and behavioural responses to threat. RESULTS: A single dose of intranasal oxytocin significantly increased the physiological startle response to threat in healthy people with a small effect size. However, oxytocin did not have significant effects on attentional bias towards social or disorder-specific threat, fixation towards threatening stimuli among healthy or clinical populations, or on threat related behavioural approach or avoidance responses. LIMITATIONS: No studies investigated the effects of oxytocin on the startle response to threat among clinical populations. Additionally, only one of the reviewed studies had sufficient power to detect at least a moderate effect of oxytocin according to our criterion. DISCUSSION: The synthesis of literature suggest that oxytocin may influence the salience of threatening stimuli among healthy individuals, increasing the startle response to threat. It would be of interest to investigate the effects of oxytocin on the startle response to threat among clinical populations.

Meta-analysis of the effects of intranasal oxytocin on interpretation and expression of emotions.

Accurate interpretation and appropriate expression of emotions are key aspects of social-cognition. Several mental disorders are characterised by transdiagnostic difficulties in these areas and, recently, there has been increasing interest in exploring the effects of oxytocin on social-emotional functioning. This review consists of 33 studies. Fifteen of the studies included people with autism spectrum disorder, schizophrenia, borderline personality disorder, frontotemporal dementia, anorexia nervosa, bulimia nervosa, post-traumatic stress disorder, depression, and opioid and alcohol dependence. We conducted ten meta-analyses examining the effects of intranasal oxytocin on expression of emotions, emotional theory of mind, sensitivity to recognise basic emotions, and recognition of basic emotions. A single dose of intranasal oxytocin significantly improved the recognition of basic emotions, particularly fear, and increased the expression of positive emotions among the healthy individuals. Oxytocin did not significantly influence theory of mind or the expression of negative emotions among the healthy individuals. Finally, intranasal oxytocin did not significantly influence interpretation or expression of emotions among the clinical populations.

The effects of intranasal oxytocin on smoothie intake, cortisol and attentional bias in anorexia nervosa.

BACKGROUND: Anorexia nervosa (AN) is characterised by severe malnutrition as well as intense fear and anxiety around food and eating with associated anomalies in information processing. Previous studies have found that the neuropeptide, oxytocin, can influence eating behaviour, lower the neurobiological stress response and anxiety among clinical populations, and alter attentional processing of food and eating related images in AN. METHODOLOGY: Thirty adult women with AN and twenty-nine healthy comparison (HC) women took part in the current study. The study used double blind, placebo controlled, crossover design to investigate the effects of a single dose of intranasal oxytocin (40 IU) on a standard laboratory smoothie challenge, and on salivary cortisol, anxiety, and attentional bias towards food images before and after the smoothie challenge in AN and HC participants. Attentional bias was assessed using a visual probe task. RESULTS: Relative to placebo intranasal oxytocin reduced salivary cortisol and altered anomalies in attentional bias towards food images in the AN group only. The oxytocin-induced reduction in attentional avoidance of food images correlated with oxytocin induced reduction in salivary cortisol in the AN group before the smoothie challenge. Intranasal oxytocin did not significantly alter subjective feelings of anxiety or intake during the smoothie challenge in the AN or HC groups. CONCLUSIONS: Intranasal oxytocin may moderate the automated information processing biases in AN and reduce neurobiological stress. Further investigation of the effects of repeated administration of oxytocin on these processes as well as on eating behaviour and subjective anxiety would be of interest.