| 1. |
- Brooks, Samantha J, et al.
(författare)
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Obsessive-compulsivity and working memory are associated with differential prefrontal cortex and insula activation in adolescents with a recent diagnosis of an eating disorder
- 2014
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Ingår i: Psychiatry Research. - : Elsevier BV. - 0165-1781 .- 1872-7123 .- 0925-4927. ; 224:3, s. 246-253
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Tidskriftsartikel (refereegranskat)abstract
- The role of rumination at the beginning of eating disorder (ED) is not well understood. We hypothesised that impulsivity, rumination and restriction could be associated with neural activity in response to food stimuli in young individuals with eating disorders (ED). We measured neural responses with functional magnetic resonance imaging (fMRI), tested working memory (WM) and administered the eating disorders examination questionnaire (EDE-Q), Barratt impulsivity scale (BIS-11) and obsessive-compulsive inventory (OCI-R) in 15 adolescent females with eating disorder not otherwise specified (EDNOS) (mean age 15 years) and 20 age-matched healthy control females. We found that EDNOS subjects had significantly higher scores on the BIS 11, EDE-Q and OCI-R scales. Significantly increased neural responses to food images in the EDNOS group were observed in the prefrontal circuitry. OCI-R scores in the EDNOS group also significantly correlated with activity in the prefrontal circuitry and the cerebellum. Significantly slower WM responses negatively correlated with bilateral superior frontal gyrus activity in the EDNOS group. We conclude that ruminations, linked to WM, are present in adolescent females newly diagnosed with EDNOS. These may be risk factors for the development of an eating disorder and may be detectable before disease onset.
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| 2. |
- Hogenkamp, Pleunie S., et al.
(författare)
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Higher resting-state activity in reward-related brain circuits in obese versus normal-weight females independent of food intake
- 2016
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Ingår i: International Journal of Obesity. - : Springer Science and Business Media LLC. - 0307-0565 .- 1476-5497. ; 40:11, s. 1687-1692
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: In response to food cues, obese vs normal-weight individuals show greater activation in brain regions involved in the regulation of food intake under both fasted and sated conditions. Putative effects of obesity on task-independent low-frequency blood-oxygenation-level-dependent signals-that is, resting-state brain activity-in the context of food intake are, however, less well studied.OBJECTIVE: To compare eyes closed, whole-brain low-frequency BOLD signals between severely obese and normal-weight females, as assessed by functional magnetic resonance imaging (fMRI).METHODS: Fractional amplitude of low-frequency fluctuations were measured in the morning following an overnight fast in 17 obese (age: 39±11 years, body mass index (BMI): 42.3±4.8 kg m(-)(2)) and 12 normal-weight females (age: 36±12 years, BMI: 22.7±1.8 kg m(-)(2)), both before and 30 min after consumption of a standardized meal (~260 kcal).RESULTS: Compared with normal-weight controls, obese females had increased low-frequency activity in clusters located in the putamen, claustrum and insula (P<0.05). This group difference was not altered by food intake. Self-reported hunger dropped and plasma glucose concentrations increased after food intake (P<0.05); however, these changes did not differ between the BMI groups.CONCLUSION: Reward-related brain regions are more active under resting-state conditions in obese than in normal-weight females. This difference was independent of food intake under the experimental settings applied in the current study. Future studies involving males and females, as well as utilizing repeated post-prandial resting-state fMRI scans and various types of meals are needed to further investigate how food intake alters resting-state brain activity in obese humans.International Journal of Obesity advance online publication, 28 June 2016; doi:10.1038/ijo.2016.105.
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| 3. |
- Olivo, Gaia, et al.
(författare)
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Atypical anorexia nervosa is not related to brain structural changes in newly diagnosed adolescent patients.
- 2018
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Ingår i: International Journal of Eating Disorders. - : Wiley. - 0276-3478 .- 1098-108X. ; 51:1, s. 39-45
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Patients with atypical anorexia nervosa (AN) have many features overlapping with AN in terms of genetic risk, age of onset, psychopathology and prognosis of outcome, although the weight loss may not be a core factor. While brain structural alterations have been reported in AN, there are currently no data regarding atypical AN patients.METHOD: We investigated brain structure through a voxel-based morphometry analysis in 22 adolescent females newly-diagnosed with atypical AN, and 38 age- and sex-matched healthy controls (HC). ED-related psychopathology, impulsiveness and obsessive-compulsive traits were assessed with the Eating Disorder Examination Questionnaire (EDE-Q), Barratt Impulsiveness Scale (BIS-11) and Obsessive-compulsive Inventory Revised (OCI-R), respectively. Body mass index (BMI) was also calculated.RESULTS: Patients and HC differed significantly on BMI (p < .002), EDE-Q total score (p < .000) and OCI-R total score (p < .000). No differences could be detected in grey matter (GM) regional volume between groups.DISCUSSION: The ED-related cognitions in atypical AN patients would suggest that atypical AN and AN could be part of the same spectrum of restrictive-ED. However, contrary to previous reports in AN, our atypical AN patients did not show any GM volume reduction. The different degree of weight loss might play a role in determining such discrepancy. Alternatively, the preservation of GM volume might indeed differentiate atypical AN from AN.
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| 4. |
- Olivo, Gaia, et al.
(författare)
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Resting-State Bra in and the FTO Obesity Risk Allele : Default Mode, Sensorimotor, and Salience Network Connectivity Underlying Different Somatosensory Integration and Reward Processing between Genotypes
- 2016
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Ingår i: Frontiers in Human Neuroscience. - : Frontiers Media SA. - 1662-5161. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- Single-nucleotide polymorphisms (SNPs) of the fat mass and obesity associated (FTO) gene are linked to obesity, but how these SNPs influence resting-state neural activation is unknown. Few brain-imaging studies have investigated the influence of obesity-related SNPs on neural activity, and no study has investigated resting-state connectivity patterns. We tested connectivity within three, main resting-state networks: default mode (DMN), sensorimotor (SMN), and salience network (SN) in 30 male participants, grouped based on genotype for the rs9939609 FTO SNP, as well as punishment and reward sensitivity measured by the Behavioral Inhibition (BIS) and Behavioral Activation System (BAS) questionnaires. Because obesity is associated with anomalies in both systems, we calculated a BIS/BAS ratio (BBr) accounting for features of both scores. A prominence of BIS over BAS (higher BBr) resulted in increased connectivity in frontal and paralimbic regions. These alterations were more evident in the obesity-associated AA genotype, where a high BBr was also associated with increased SN connectivity in dopaminergic circuitries, and in a subnetwork involved in somatosensory integration regarding food. Participants with AA genotype and high BBr, compared to corresponding participants in the TT genotype, also showed greater DMN connectivity in regions involved in the processing of food cues, and in the SMN for regions involved in visceral perception and reward-based learning. These findings suggest that neural connectivity patterns influence the sensitivity toward punishment and reward more closely in the AA carriers, predisposing them to developing obesity. Our work explains a complex interaction between genetics, neural patterns, and behavioral measures in determining the risk for obesity and may help develop individually-tailored strategies for obesity prevention.
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| 5. |
- Solstrand Dahlberg, Linda, 1988-, et al.
(författare)
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Adolescents Newly Diagnosed with Eating Disorders have Structural Differences in Brain Regions linked with Eating Disorder Symptoms
- 2017
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Ingår i: Nordic Journal of Psychiatry. - : Taylor & Francis. - 0803-9488 .- 1502-4725. ; 71:3, s. 188-196
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Tidskriftsartikel (refereegranskat)abstract
- Background: Adults with eating disorders (ED) show brain volume reductions in the frontal, insular, cingulate, and parietal cortices, as well as differences in subcortical regions associated with reward processing. However, little is known about the structural differences in adolescents with behavioural indications of early stage ED.Aim: This is the first study to investigate structural brain changes in adolescents newly diagnosed with ED compared to healthy controls (HC), and to study whether ED cognitions correlate with structural changes in adolescents with ED of short duration.Methods: Fifteen adolescent females recently diagnosed with ED, and 28 age-matched HC individuals, were scanned with structural magnetic resonance imaging (MRI). Whole-brain and region-of-interest analyses were conducted using voxel-based morphometry (VBM). ED cognitions were measured with self-report questionnaires and working memory performance was measured with a neuropsychological computerized test.Results and conclusions: The left superior temporal gyrus had a smaller volume in adolescents with ED than in HC, which correlated with ED cognitions (concerns about eating, weight, and shape). Working memory reaction time correlated positively with insula volumes in ED participants, but not HC. In ED, measurements of restraint and obsession was negatively correlated with temporal gyrus volumes, and positively correlated with cerebellar and striatal volumes. Thus, adolescents with a recent diagnosis of ED had volumetric variations in brain areas linked to ED cognitions, obsessions, and working memory. The findings emphasize the importance of early identification of illness, before potential long-term effects on structure and behaviour occur.
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| 6. |
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| 7. |
- Solstrand Dahlberg, Linda, 1988-
(författare)
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Assessment of Function, Structure and Working Memory in Adolescents with a Recent Diagnosis of an Eating Disorder
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Body, weight and shape related obsessions and ruminations are characteristic traits of individuals with eating disorders (ED) that are found to predate the onset of the disorder. Individuals with chronic ED display altered neural activation in response to food stimuli, and are reported to have volumetric differences compared to healthy individuals, which is likely an effect of prolonged starvation. ED individuals are also seen to dispose an attentional bias to food stimuli, even when perceived sub-consciously, which are reported to interfere with cognitive tasks, including working memory (WM). However, whether the differences in neural activation and structure are present in adolescents with a recent ED diagnosis is not known.In paper I we describe how images of high- and low-calorie foods resulted in greater responses in the prefrontal circuitry in ED adolescents compared to healthy controls (HC). Obsessive-compulsive symptoms in ED individuals were associated with prefrontal circuitry and cerebellar activation, whereas faster reaction times to the WM were associated with greater superior frontal gyrus activity. The findings indicate that ED cognitions may be linked to WM abilities, both of which are associated with frontal cortex functioning. WM performance is examined further in paper II, where we found that the presence of subliminal food images were seen to disrupt WM performance in terms of slower reaction times and less correct responses in ED but not HC. The WM interference was associated with increased activity in the parietal and superior temporal cortex. WM interference caused by subliminal food stimuli may reflect a pre-attentive bias to food in adolescents with ED, which could be a risk factor for further development of an ED.The structural differences in brain volume between adolescents with ED and HC were examined in paper III. ED symptoms were found to be associated with volume differences in insular cortex and superior temporal gyrus, whereas obsessive-compulsive symptoms were associated with reduced volumes in the putamen and cerebellum. These volumetric differences in regions implicated in restraint, obsessions and WM are likely to precede structural variations caused by starvation as seen in chronic ED’s. Connectivity from these regions, in addition to other regions believed to be implicated in ED, was studied in paper IV. Fronto-parietal regions as well as the insula showed increased connectivity in ED, whereas connectivity from the mesolimbic reward regions did not differ from HC. Regions with increased connectivity in ED are involved with self-awareness, body image and ED related ruminations, connections that could influence how one’s body is perceived.In conclusion, the studies included in this thesis describes changes in functional activity, connectivity and brain volume in regions involved with ED cognitions, eating behaviour, and body image in adolescents recently diagnosed with an ED.
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| 8. |
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| 9. |
- Wiemerslage, Lyle, et al.
(författare)
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An obesity-associated risk allele within the FTO gene affects human brain activity for areas important for emotion, impulse control and reward in response to food images
- 2016
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Ingår i: European Journal of Neuroscience. - : Wiley. - 0953-816X .- 1460-9568. ; 43:9, s. 1173-1180
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Tidskriftsartikel (refereegranskat)abstract
- Understanding how genetics influences obesity, brain activity and eating behaviour will add important insight for developing strategies for weight-loss treatment, as obesity may stem from different causes and as individual feeding behaviour may depend on genetic differences. To this end, we examined how an obesity risk allele for the FTO gene affects brain activity in response to food images of different caloric content via functional magnetic resonance imaging (fMRI). Thirty participants homozygous for the rs9939609 single nucleotide polymorphism were shown images of low-or high-calorie food while brain activity was measured via fMRI. In a whole-brain analysis, we found that people with the FTO risk allele genotype (AA) had increased activity compared with the non-risk (TT) genotype in the posterior cingulate, cuneus, precuneus and putamen. Moreover, higher body mass index in the AA genotype was associated with reduced activity to food images in areas important for emotion (cingulate cortex), but also in areas important for impulse control (frontal gyri and lentiform nucleus). Lastly, we corroborate our findings with behavioural scales for the behavioural inhibition and activation systems. Our results suggest that the two genotypes are associated with differential neural processing of food images, which may influence weight status through diminished impulse control and reward processing.
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