When I was a teenager, I kept a worry monster under my bed. Wendy the Worrier was round, green, had big staring eyes and a large grimacing smile. Her mouth was unzippable so, whenever I had a worry at night, I would write it down and feed it to her. Over time, her belly grew until she couldn’t carry any more, at which point I would have to empty her out and start again. I always found that most of Wendy’s concerns never actually happened, but that didn’t stop her from worrying.
Excessive or uncontrollable worry is not rare in adolescence, with 3% of young people suffering from generalised anxiety disorder (GAD), a mental health problem defined by pathological worry (Gale & Millichamp, 2016). However, the type of worry associated with GAD does not necessarily remain constant over time. Similarly, other GAD symptoms such as nervousness and irritability may become more or less prominent as time goes by. Li et al. (2024) thus wanted to investigate whether the clinical presentation of adolescent GAD changes with age, and which symptoms may be the most effective targets for prevention and intervention.
Do generalised anxiety symptoms change over time? Li et al. (2024) undertook a network analysis to investigate symptom change from early adolescence to emerging adulthood to identify targets for prevention and intervention.
Methods
Li et al. (2024) analysed data from the Chinese Mental Health Database, specifically a nationally representative online survey of 65,000 10-24-year-olds in education. Participants self-reported their GAD symptoms and were divided into four age categories:
- Early adolescence (10-12 years)
- Middle adolescence (13-15 years)
- Late adolescence (16-18 years)
- Emerging adulthood (19-24 years).
51% of the sample was female and the prevalence of generalised anxiety symptoms was 6.97% overall. Symptoms were more prevalent in females than males across all age groups, with the middle adolescence group showing the highest rate of GAD symptoms (12% in females and 8% in males).
Network analyses first estimated the strength centrality of different symptoms across these age groups (i.e., the importance of different GAD symptoms, determined both by how many other symptoms they connected to and the strength of these connections). After determining whether GAD symptom networks changed over time, the researchers simulated the effects of intervening at the level of different symptoms across the four developmental stages.
Results
In all four networks, the strongest connections were between nervousness and uncontrollable worry and uncontrollable and excessive worry, indicating how these symptoms play a central role in causing and maintaining each other regardless of age. In early adolescence, excessive worry and irritability had the highest symptom centrality, followed by uncontrollable worry. In contrast, uncontrollable worry was the most central symptom in older participants. In late adolescence, both excessive and uncontrollable worry represented the core symptoms of the network; in middle adolescence and emerging adulthood, though, only uncontrollable worry had the highest centrality.
| Age Group | Most Central Symptoms | Prevention Targets | Treatment Targets |
| Early Adolescence | Excessive worry, Irritability, Uncontrollable worry | Excessive worry, Irritability, Feeling afraid, Nervousness | Reducing nervousness and irritability most beneficial |
| Middle Adolescence | Uncontrollable worry | Uncontrollable worry | Reducing nervousness, excessive worry |
| Late Adolescence | Excessive worry, Uncontrollable worry | Uncontrollable worry | Reducing nervousness, excessive worry |
| Emerging Adulthood | Uncontrollable worry | Uncontrollable worry | Reducing nervousness, excessive worry |
| General Trend | Uncontrollable worry remains high; overall network strength increases with age | Excessive worry early; Uncontrollable worry later | Nervousness reduction consistently beneficial across all ages |
When comparing GAD (generalised anxiety disorder) symptoms across networks, the strength centrality of excessive worry, uncontrollable worry and restlessness was found to increase after early adolescence, whilst that of feeling fear reduced. The centrality of struggling to relax decreased from middle and late adolescence to young adulthood, as did that of excessive worry after late adolescence. Overall, the importance of feeling afraid, struggling to relax and excessive worry decreased from adolescence to adulthood, whilst the significance of uncontrollable worry remained high. Finally, the global strength of the entire GAD network progressively increased with age, indicating that anxiety symptoms become more strongly interconnected over time. This implies that individuals become more vulnerable to developing GAD in consequence, as it becomes easier for symptoms to activate each other as we age.
In line with these findings, the effects of intervening at the level of different symptoms on the network state (i.e., the activation energy of the network, representing GAD severity) varied over time. Simulations that aggravated excessive worry, followed by irritability, feeling afraid and nervousness, were most detrimental in early adolescence. In contrast, interventions amplifying uncontrollable worry exerted the strongest negative influence across all subsequent age groups. Hence, not all symptoms increase the likelihood of developing GAD to the same extent, with excessive and uncontrollable worry constituting the most crucial prevention targets in early and later adolescence, respectively.
In terms of improving GAD, interventions that alleviated nervousness were most beneficial across the board, followed by excessive worry. In addition, reducing irritability was highly beneficial for early adolescents (corresponding to the higher relative centrality of this symptom in this age category compared to older groups). These data thus highlight how the relative importance of different symptoms varies according to whether the intervention aims to prevent or treat GAD.
Across the four different networks in Li et al.’s (2024) network analysis, the strongest connections were between nervousness and uncontrollable worry, and uncontrollable and excessive worry, highlighting their potential role in maintaining anxiety.
Conclusions
Overall, this network analysis found that the importance of different GAD symptoms changes over time in young people, corresponding to a time-variant effectiveness of targeting different symptoms for intervention. The authors concluded that:
The symptom involvement in networks varies with age, suggesting the need for distinct prevention and treatment strategies based on developmental stages.
In particular, uncontrollable worry gradually replaced excessive worry as the symptom both most central to the network and exerting the most detrimental impact on GAD levels. Age effects were less pronounced for treatment simulations compared to prevention, with nervousness and excessive worry emerging as critical targets regardless of developmental stage.
Excessive and uncontrollable worry represent important prevention targets for generalised anxiety disorder in early adolescence and older adolescence respectively.
Strengths and limitations
The study’s large sample and stratified sampling technique helped to ensure that adolescents across the entirety of China were adequately represented. However, the authors only sampled youth who were currently in education, so the findings may not generalise to all young people. This issue is especially pertinent to the emerging adulthood group, as there may be meaningful mental health differences between those who do and do not attend university (Blanco et al., 2008). As the phenomenology of anxiety varies cross-culturally (Marques et al., 2011), future research should also investigate to what extent the findings apply to other sociocultural settings.
By using validated measures, the authors strengthened the study’s validity, giving confidence that the tools accurately captured what they were intended to—GAD symptoms in adolescence. However, the reliability of the findings remains questionable, as sensitivity analyses did not always confirm the results. These analyses found that the optimal intervention targets changed depending on the magnitude of the simulated intervention. Hence, we may need to consider both the target and intensity of interventions aiming to treat adolescent GAD; future research must explore whether these findings hold up.
A critical limitation comprised the cross-sectional nature of the study. By comparing across age groups, the authors inferred a pattern of change in GAD over time. However, what is true for the group on average may not apply to the individual, so the findings masked potential variability in the trajectory of anxiety symptoms. The single snapshot in time also cannot rule out the possibility that different groups experienced different environmental factors leading to different types of worry (and other symptoms), rather than an inherent change over time. Longitudinal research is needed to address these issues.
Finally, although simulated interventions are a cost-effective and compelling way to estimate the effects of intervening in the real world, their results are preliminary and must be interpreted with caution. Not only did different perturbation strengths (magnitudes of intervention) result in different outcomes, but real life is inherently more complex than network models. It remains a very real possibility that the most promising intervention targets in reductionist and simplified models will not translate to naturalistic settings, so future work must assess the effects of real interventions on real participants in real settings.
Longitudinal research is needed to investigate individual trajectories of anxiety symptoms and rule out the role of environmental factors in explaining differences observed cross-sectionally.
Implications for practice
As GAD symptom networks become more strongly connected over time, older adolescents may be more vulnerable to developing pathological self-sustaining states of both high symptom activation and interconnection. These networks may be less amenable to change (as strong connections may be more difficult to treat), so early intervention seems crucial in order to prevent GAD from escalating.
The stimulations pointed to excessive worry as the most critical symptom to target in order to prevent GAD in early adolescence, while uncontrollable worry emerged as the most important factor in later stages. These findings are of value in terms of identifying adolescents at risk for GAD and suggest that teaching young people techniques to manage such worry may prove beneficial. If the findings are replicated in real (non-simulated) intervention research, schools could be encouraged to incorporate worry-management strategies into their curricula (e.g., in PSHE).
Concerning the treatment of GAD, nervousness and excessive worry emerged as the most effective factors to target, indicating that therapists should pay particular attention to these symptoms when working with young people. Addressing irritability in early adolescence also seems beneficial. Although real-life treatment trials are similarly needed to confirm the efficacy of preferentially focusing on particular symptoms in treatment, the simulations open up the exciting new possibility of individualised interventions tailored to the developmental stage of the young person. It is to be hoped that such a flexible, empirically grounded approach will improve the success rates of current psychological interventions for adolescent GAD. If so, the current research programme could be extended even further to assess whether certain symptoms are more important than others in terms of relapse prevention, and whether this effect similarly varies over time. Indeed, the focus of the research could be widened to investigate age differences in the anxiety network of children or older adults, as well.
Li et al.’s (2024) data align with Wendy the Worry Monster’s lived experience. Over the course of several years, the worries she gobbled up morphed from excessive to uncontrollable. After a certain point, though, she started a much-needed diet. She gradually consumed less and less, and eventually she was retired. It is to be hoped that research findings such as these will help other worry monsters – and their owners – live lives less consumed by worry and the associated anxiety it brings, and instead experience worry as just one small part of a healthy balanced life.
Li et al.’s (2024) exciting findings hint at the possibility of developing age-sensitive prevention and treatment programmes for generalised anxiety disorder in adolescence, but we need to go beyond simulations.
Statement of interests
I have no conflicting interests with respect to the content of this blog post.
Links
Primary paper
Li, F., Zhang, Y., Fang, Y., & Chen, Z. (2024). Effective targets of intervention on generalized anxiety symptoms across whole adolescence and emerging adulthood: network analysis and in silico intervention. European Child & Adolescent Psychiatry, 1-12.
Other references
Blanco, C., Okuda, M., Wright, C., Hasin, D. S., Grant, B. F., Liu, S., & Olfson, M. (2008). Mental health of college students and their non–college-attending peers: Results from the National Epidemiologic Study on Alcohol and Related Conditions. Archives of General Psychiatry, 65(12), 1429–1437.
Gale, C. K., & Millichamp, J. (2016). Generalised anxiety disorder in children and adolescents. BMJ Clinical Evidence, 2016, 1002.
Marques, L., Robinaugh, D. J., LeBlanc, N. J., & Hinton, D. (2011). Cross-cultural variations in the prevalence and presentation of anxiety disorders. Expert Review of Neurotherapeutics, 11(2), 313-322.
