Question 1: Can Eating disorder be considered as a network?
- Understanding interrelationship between different components: emotion regulation, interpersonal problems, and eating disorder can be conceptualized as a symtom network via theoretical frameworks
The Emotion regulation theory suggests difficulty in emotion regulation issues can results in ED behaviors
Interpersonal psychotherapy theory posits that interpersonal problems may exacerbate ED (Murphy et al., 2012)
Empirical studies considered these three consitute a “ecosystem” (Ambwani et al., 2014). ER and interpersonal function exibit reciprocal effects on ED maintance.
However, the dynamics of eating disorders has not been well investigated.
Question 1: Can Eating disorder be considered as a network?
- Examine why ED have a network-like structure
- Some considered the development of ED as a longitudinal process (Mallorquí-Bagué et al., 2018)
- Some argue that the relations between risky factors (emotion, interpersonal relations) and ED are complex (i.e., feedback loop)
- Additionally, some highlight that boys or girls also exibit gender difference regarding the developmental process of ED
Question 2: Why psychological network can be used for this topic?
Longitudinal network analysis have been widely applied in psychopathology and proven as a suitable tool for addressing the problems mentioned in the first general question.
- It considers symptoms related to each other as in a symptom network.
- It allows us to identify the most important symptoms (disordered behaviors) in this complex network
- It can estimate temporal effects of one symptom on the others controlling effects of other variables
Question 2: Why psychological network can be used for this topic?
We estimated network parameters using graphical vector autoregressive (GVAR; Epskamp, 2020; Wild et al., 2010) algorithm
Three types of network structures are estimated:
Temporal network (temporal effect)
Contemporaneous network (within-person effects controlling for temporal effects)
Between-individual network (individual differences)
Question 3: How to compare groups in longitudinal network
In network analysis, groups can be compared from three aspects:
Network structure (e.g., some nodes connected in group A but not in group B)
Node-level measures: node centrality (importance) or node bridging strength (e.g., some nodes can be more central in group A while not in group B)
Network edge weights (e.g., node 1 and node 2 have strong relationship in group A but weaker relationship in group B)
Things to be considered
Which variables (nodes) should be included in the network?
- Items?
- Subscale scores?
- Latent factor scores?
- Mixed
There are no clear rules of node types. It depends on theory model.
- Are different networks comparable?
The network of sample A differs from the network of sample B in term of network structures or centrality measures. They only have quantative differences in parameter estimates or they are measuring different constructs?
Research Questions:
Are there any gender differences in the network characteristics of longitudinal networks
Are there any gender differences in the network structures of eating disorder longitudinal networks
Are there any gender differences in the node centrality and bridge strength of longitudinal networks
Data
4-wave data collection were conducted over 18 months.
For each wave, demographic information and self-reported answers of three questionnaires (emotional regulation, interpersonal problems, and eating disorder) from 1652 high school students in China were collected.
After data cleaning, N = 1540 cases left including 53.9% girls and 46.1% boys
Age ranges from 11 to 17 years with a mean 15.2 years old
Measures
For network analysis, we used subscales and items as nodes.
- Emotion regulation: Difficulties in Emotion Regulation Scale (DERS-18). 6 subscales measures different aspects of emotion dysregualtion: Awareness, Clarity, Goals, Non-acceptance, Impulse, Strategies
- Interpersonal problems: Inventory of Interpersonal Problems—Short Circumplex (IIP-SC). 8 subscales were included measuring varied aspects of interpersonal problems: domineering, cold, avoidant etc.
- Eating disorder: 12-item short form of Eating Disorder Examination Questionnaire (EDE-QS). 12 items measured different disordered eating behaviors.
We have 26 nodes in initial networks.
Data Analysis
1. Node (item) selection
For emotion regulation and interpersonal problem questions, 14 subscales were selected because their measured constructs have been well examined and theory-driven.
For eating disorder, we want to makre sure each item represent one unique eating disorder problem. Thus, we used the goldbricker algorithm to drop overalapping (dupplicated) symptoms, which give rise to 8 items included in the analyzed network.
We have 22 nodes in further network analysis.
2. Network estimation
Multi-group GVAR was applied to the data to estimate boys’ and girls’ temporal/contemporaneous/between-subject network.
Furthermore, we pruned the networks and identify the most important nodes and edges using prune function in psychonetric package in R.
Data Analysis (Cont.)
3. Overall network evaluation
- Network stability measured by correlation stability (CS) coefficients (Epskamp et al., 2018), which estimates the accuracy of centrality measures and node strength using bootstrapping
4. Test group differences
