Anxiety and mood disorders are some of the most common psychiatric conditions presented in primary care. With the great volume of research showing the relationships between anxiety, depression, and somatization—defined in the Oxford English Dictionary as “the occurrence of bodily symptoms in consequence of or as an expression of mental disorder” (“Somatization”)—it seems that understanding their development during adolescence is critical for prevention and intervention. Recent research at the University of Ottawa looks at the temporal patterning of anxiety, depression, and somatization in adolescents. This study aimed to distinguish between-person from within-person effects in order to separately examine intra-individual symptom change over time (within-person effects) and the contribution of certain risk factors on symptom trajectories (between-person effects) (Lee and Vaillancourt).
These researchers took data from the McMaster Teen Study, where a cohort of Canadian children (54% girls; 76% White) was randomly recruited and followed starting 2008 for 7 years, from the age of 11 to 17 (Lee and Vaillancourt). In this study, the children were asked to complete a paper or electronic questionnaire (BASC-2), while parents (87% mothers) were asked to take part in phone interviews (Brief Child and Family Phone Interview 3). Data was collected on anxiety, depression, and somatization. Covariates such as chronic bullying victimization (Olweus Bully/Victim questionnaire), child maltreatment (Childhood Experiences of Violence Questionnaire Short-Form), and socioeconomic indicators were also measured via questionnaires (Lee and Vaillancourt).
With this data, autoregressive latent trajectory models were then used to disaggregate between-person from within-person effects. Regarding within-person effects, these models showed “significant bivariate correlations” among anxiety, depression, and somatization at every single time point (Lee and Vaillancourt). The study reports that, rather consistently, anxiety successfully predicted depression, while both anxiety and depression predicted somatization (Lee and Vaillancourt).
Furthermore, regarding between-person effects, there seemed to also be positive correlations among the intercepts (latent means) of anxiety, depression, and somatization (Lee and Vaillancourt). According to some researchers, latent means comparison “can generate more accurate results than the composite scores comparison using t test or analysis of variance (ANOVA) as the latent variables are free of measurement errors” (Han et al.). For instance, sex positively predicted every intercept, with girls having higher latent means of all three conditions (Lee and Vaillancourt). Also, chronic bullying victimization and physical abuse positively predicted the intercepts of all three, while sexual abuse positively predicted the intercept of somatization and the slopes (trajectories) of both anxiety and depression. Education negatively predicted the intercept of somatization, while income negatively predicted the intercepts of anxiety and depression (Lee and Vaillancourt).
Generally speaking, generalized anxiety was an early symptom of depression and somatization in the adolescents, and intra-individual shifts in anxiety symptoms seemed to increase risks of early depressive and somatic symptoms rather consistently (Lee and Vaillancourt). And as shown by prior research, comorbidity was the rule rather than the exception. The researchers remark: “The evolution of symptoms as reported by adolescents (anxiety→depression→somatization) may reflect a progression of symptom severity (Simms et al., 2012), with physical pain being the end point” (Lee and Vaillancourt). Their findings pave the way for a better understanding of anxiety and mood disorders in adolescents.
Han, Chen, et al. “Measurement Invariance and Latent Mean Differences of the Chinese Version Physical Activity Self-Efficacy Scale across Gender and Education Levels.” Journal of Sport and Health Science, vol. 8, no. 1, Jan. 2019, pp. 46–54, https://doi.org/10.1016/j.jshs.2017.01.004.
Lee, Kirsty S. and Tracy Vaillancourt. “The role of childhood generalized anxiety in the internalizing cluster.” Psychological Medicine, vol. 50, 2020, pp. 2272–2282, https://doi.org/ 10.1017/S0033291719002484.
“Somatization.” Oxford English Dictionary, www.oed.com/view/Entry/184426?redirectedFrom=somatization#eid.