Mediation models of anxiety and depression between temperament and drive for thinness and body dissatisfaction in anorexia nervosa

Weight gained during treatment predicts 6-month body mass index in a large sample of patients with anorexia nervosa using ensemble machine learning

OBJECTIVE

This study used machine learning methods to analyze data on treatment outcomes from individuals with anorexia nervosa admitted to a specialized eating disorders treatment program.

METHODS

Of 368 individuals with anorexia nervosa (209 adolescents and 159 adults), 160 individuals had data available for a 6-month follow-up analysis. Participants were treated in a 6-day-per-week partial-hospital program. Participants were assessed for eating disorder-specific and non-specific psychopathology. The analyses used established machine learning procedures combined in an ensemble model from support vector machine learning, random forest prediction, and the elastic net regularized regression with an exploration (training; 75%) and confirmation (test; 25%) split of the data.

RESULTS

The models predicting body mass index (BMI) at 6-month follow-up explained a 28.6% variance in the training set (n = 120). The model had good performance in predicting 6-month BMI in the test dataset (n = 40), with predicted BMI significantly correlating with actual BMI (r = .51, p = 0.01). The change in BMI from admission to discharge was the most important predictor, strongly correlating with reported BMI at 6-month follow-up (r = .55). Behavioral variables were much less predictive of BMI outcome. Results were similar for z-transformed BMI in the adolescent-only group. Length of stay was most predictive of weight gain in treatment (r = .56) but did not predict longer-term BMI.

CONCLUSIONS

This study, using an agnostic ensemble machine learning approach in the largest to-date sample of individuals with anorexia nervosa, suggests that achieving weight gain goals in treatment predicts longer-term weight-related outcomes. Other potential predictors, personality, mood, or eating disorder-specific symptoms were relatively much less predictive.

PUBLIC SIGNIFICANCE

The results from this study indicate that the amount of weight gained during treatment predicts BMI 6 months after discharge from a high level of care. This suggests that patients require sufficient time in a higher level of care treatment to meet their specific weight goals and be able to maintain normal weight.

Perfectionism in anorexia nervosa: Associations with clinical picture and personality traits

Although many researchers addressed the topics, no consistent data are currently available regarding the relationship between perfectionism and personality traits in anorexia nervosa (AN). The present study aimed to assess differences between high- and low-perfectionism groups of patients with AN and to identify which variables show the strongest association with perfectionism. A group of inpatients with AN (n = 193) was recruited and completed a battery of self-report questionnaires regarding eating-related and general psychopathology, perfectionism, and personality. On the basis of perfectionism scores, patients were divided into high- and low-perfectionism groups. High-perfectionist patients displayed higher eating-related and general psychopathology; higher depressive, cyclothymic, irritable and anxious temperament, and lower self-directedness, cooperativeness and self-esteem. Perfectionism was associated with the drive for thinness, cooperativeness, self-esteem and anxious temperament. On the basis of the two personality traits most strongly correlated with perfectionism (i.e., cooperativeness and anxious temperament), patients could be correctly assigned to the high- or low-perfectionism group by an algorithm. The study suggests that perfectionism in AN is related to eating psychopathology, especially of restrictive type, and personality features such as cooperativeness and anxious temperament. These findings confirm the important role of perfectionism in AN, not only concerning eating behaviour but personality as well.

Abnormal sense of agency in eating disorders

The feeling of controlling one's own actions and, through them, impacting the external environment (i.e. Sense of Agency-SoA) can be relevant in the eating disorders (EDs) symptomatology. Yet, it has been poorly investigated. This study aims to implicitly assess SoA exploiting the Sensory Attenuation paradigm in two groups of EDs patients (Anorexia Nervosa Restrictive and Anorexia Nervosa Binge-Purging or Bulimia Nervosa) compared to a control group. We find that controls perceive self-generated stimuli as less intense than other-generated ones showing the classic pattern of sensory attenuation. By contrast, EDs patients show the opposite pattern, with self-generated perceived as more intense than other-generated stimuli. This result indicates an alteration of the implicit component of the feeling of control in EDs patients, thus suggesting a potential implication of these results for the clinical practice and the treatment of EDs symptomatology.

Risk factors of disordered eating in adolescent girls from a community sample: a multidimensional approach

BACKGROUND

Eating disorders (ED) are severe, chronic, and complex in nature mental illnesses that are difficult to treat. One of the ways to stave off EDs is by screening among adolescents to preempt the development of clinical forms of ED in risk groups.

AIM

1) to investigate the prevalence of ED risk among adolescent girls and compare subgroups at high and low risk of ED; 2) to investigate using a multidimensional approach those variables that can interact with temperament and character traits to predict ED symptomatology.

METHODS

The cross-sectional observational self-report study of a community sample of adolescent girls 1217 years old (n=298; M=14.771.13) was carried out in the city of Ryazan, Russia. The Russian versions of Eating Attitudes Test and Cloningers Temperament and Character Inventory-Revised were used. In addition, an original questionnaire (Risk Factors of Eating Disorders) was developed. Regression models (to test for significant moderation) and path analysis (to test for significant mediations) were used.

RESULTS

Girls at risk of developing EDs are characterized by a heightened level of concern about weight and dissatisfaction with their body, tend to suffer from low self-directedness, higher novelty seeking and tendency to higher harm avoidance, display high alexithymia, experience self-distrust, negative emotionality and are dissatisfied with family relationships. They also suffer from low self-esteem and tend to be perfectionism and engage in risk behavior. Significant moderating effects were uncovered between the following ED risk factors: (1) self-distrust/risk behavior and BMI; (2) alexithymia/negative emotionality/self-esteem and cooperativeness; and (3) negative emotionality/risk behavior and self-transcendence. Family relationship dissatisfaction mediates the association between self-directedness/cooperativeness/self-transcendence and disordered eating.

CONCLUSION

There are various mutual influences between the numerous ED risk and prevention factors, which all together determine the paths between the predictors and final outcome.

The mediating role of anxiety and depression between problematic social media use and bulimia nervosa among Lebanese university students

Background

Bulimia nervosa (BN) is a disorder that is characterized by binge eating and inappropriate compensatory behavior to control weight. The aim of this study was to evaluate the mediating role of anxiety and depression between problematic social media use (PSMU) and BN among a sample of Lebanese university students.

Methods

This cross-sectional study was carried out between July and September 2021; a total of 363 university students was recruited through convenience sampling. The PROCESS SPSS Macro version 3.4, model four was used to test the indirect effect and calculate three pathways. Pathway A determined the regression coefficient for the effect of PSMU on mental health issues (depression/anxiety); Pathway B examined the association between mental health issues on BN, and Pathway C’ estimated the direct effect of PSMU on BN. Pathway AB was used to calculate the indirect effect of PSMU on BN via depression/anxiety.

Results

Results showed that depression and anxiety partially mediated the association between PSMU and BN. Higher levels of PSMU were associated with more depression and anxiety; higher depression and anxiety were associated with more BN. PSMU was directly and significantly associated with more BN. When entering anxiety (M1) then depression (M2) as consecutive mediators in a first model, the results showed that only depression mediated the association between PSMU and bulimia. When taking depression (M1) then anxiety (M2) as consecutive mediators in a second model, the results showed that the mediation PSMU → Depression → Anxiety → Bulimia was significant. Higher PSMU was significantly associated with more depression, which was significantly associated with more anxiety, which was significantly associated with more bulimia. Finally, higher PSMU was directly and significantly associated with more bulimia

Conclusion

The current paper highlights the relationship that social media use has on BN and other aspects of mental health such as anxiety and depression in Lebanon. Future studies should replicate the mediation analysis conducted in the current study while taking into account other eating disorders. Additional investigations of BN and its correlates must strive to improve the comprehension of these associations’ pathways through designs that allow to draw temporal frameworks, in order to efficiently treat this eating disorder and prevent its negative outcomes.

Bulimia nervosa, an eating disorder, is characterized by an impulsive consumption of food in a short period of time, followed by behaviors that compensate the eating such as vomiting or excessive exercise in order to avoid weight gain. Individuals with problematic social media use were found to have higher levels of bulimia symptoms. Symptoms of bulimia can also be associated with both depression and anxiety. The aim of the current study was to examine the mediating role of anxiety and depression between problematic social media use and bulimia nervosa. The results of our study found that problematic social media use was directly associated with more bulimia nervosa and also associated with higher depression and anxiety, both of which were associated with bulimia nervosa. Tackling associated disorders may help reduce symptoms of bulimia nervosa. Clinicians should carefully examine these associations while assessing and implementing treatment plans.