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A large study of teenagers reveals that specific patterns of unhealthy daily habits predict a higher risk of developing both anxiety and depression simultaneously. The findings highlight how different lifestyle risks group together to influence adolescent mental health over time. The study was published in the journal BMC Psychiatry.
Adolescents are in a sensitive period for physical and mental development. During these years, teenagers often pick up habits that can harm their well-being, such as skipping meals, spending hours on screens, or staying up late. These actions rarely happen in isolation. Instead, they tend to group together within the same individuals.
When a person experiences two mental health conditions at the same time, professionals refer to this as a comorbidity. Anxiety and depression share many behavioral and environmental risk factors, making them a common comorbid pair. Adolescents facing both conditions often experience more severe symptoms, a higher risk of relapse, and more suicidal behavior than those dealing with just one.
Researchers Wanyu Che, Ziyan Ruan, and Xiaoyan Wu of Anhui Medical University led a team to investigate how clustered lifestyle habits relate to these combined mental health challenges. They wanted to see if identifying specific groupings of behaviors could help predict the future onset of combined anxiety and depression. Understanding the behavioral roots of these conditions could aid in early prevention efforts.
The researchers conducted a large study tracking 6,656 adolescents across eight regions in China. The participants lived in a mix of first-tier and second-tier cities, encompassing both urban and rural areas. The average age of the students was about 14 years old, evenly split between middle school and high school grades.
The team surveyed the participants twice, with the baseline assessment in late 2021 and a follow-up a year later. Students completed electronic questionnaires on their smartphones during class time. The researchers asked about 15 specific unhealthy behaviors to build a comprehensive picture of their daily routines.
These behaviors included smoking, alcohol consumption, physical inactivity, poor sleep duration, late bedtimes, and excessive screen time on weekdays and weekends. The survey also tracked dietary habits like insufficient fruit or vegetable intake, frequent fast food consumption, skipping breakfast, and drinking sugary beverages. Finally, the questionnaire asked about suicide-related thoughts, plans, and actions.
The team also evaluated the participants for anxiety and depression using standard self-report scales. They identified students who scored above the symptom screening cutoffs for both conditions simultaneously at the one-year follow-up.
Before looking at the behavior clusters, the researchers noted demographic differences in mental health outcomes. At the one-year mark, 13.6 percent of the participants experienced comorbid anxiety and depression. The rates were notably higher among girls than boys. Students who reported a heavy learning burden, those from poorer families, and teenagers with two or fewer friends also showed elevated rates of both conditions.
Using statistical modeling, the researchers grouped the students based on their behavioral patterns. They identified four distinct categories. The first category was a low-risk group, making up 24 percent of the sample. These teenagers consistently reported very few of the 15 unhealthy behaviors.
The second category, encompassing roughly 40 percent of the students, was defined by poor dietary habits. These individuals frequently skipped breakfast, ate fast food, and consumed too few fruits and vegetables. The third category was a sedentary and screen-time group, representing 22 percent of the teenagers. This group exhibited low physical activity combined with heavy device usage.
The final category was a multiple unhealthy behaviors group, which made up almost 14 percent of the sample. Teenagers in this group showed high rates of almost all 15 behaviors. This included a higher likelihood of reporting suicidal thoughts and actions alongside poor diet and sleep habits.
The researchers also looked at the sheer volume of unhealthy habits per student. They found that more than half of the participants engaged in four to six of the listed behaviors. About a quarter of the teenagers reported having seven or more of these habits.
To understand the impact on mental health, the researchers adjusted their analysis to account for outside factors that might skew the results, such as family income, number of friends, academic pressure, and family history of depression. After these adjustments, the data showed that students in the sedentary and multiple unhealthy behavior groups faced a substantially higher risk of developing combined anxiety and depression than those in the low-risk group.
The risk also climbed as the total number of unhealthy habits increased. Teenagers with seven or more poor habits had nearly triple the odds of experiencing both mental health conditions compared to those with three or fewer habits.
The researchers anticipated that including suicide-related items in the behavior list might artificially inflate the connection to depression. To test the strength of their findings, they ran a second analysis that removed the three suicide-related questions.
This secondary analysis focused entirely on the remaining 12 lifestyle factors, such as diet, sleep, and exercise. The results held steady. The grouping of poor physical habits still predicted a substantially higher risk of future anxiety and depression, showing that the lifestyle factors independently contribute to mental health vulnerability.
The study authors suggest that these clustered behaviors likely represent a shared foundation that contributes to internalizing problems during adolescence. Rather than acting as specific triggers for either anxiety or depression alone, these habit profiles might act as common risk factors that elevate a teenager’s overall psychological vulnerability.
The study relies on self-reported questionnaires, which can introduce bias. Teenagers might not remember their daily routines perfectly or might be reluctant to report certain actions honestly.
The sample only included adolescents currently enrolled in middle or high schools. Teenagers who drop out of school might experience different environments and higher rates of risk behaviors, meaning these findings might not perfectly reflect the broader youth population.
The study is observational and cannot prove that these habits directly cause mental health conditions. Unmeasured variables, such as early childhood trauma or neighborhood environments, could independently influence both a teenager’s daily habits and their psychological well-being.
Future research could explore whether community or school programs designed to change these clustered behaviors actually prevent mental health conditions. By addressing groups of habits together, health professionals might offer better support for adolescent development.
The study, “Associations of clustered unhealthy lifestyle behaviors with comorbidity of anxiety and depression among adolescents,” was authored by Wanyu Che, Ziyan Ruan, Shuman Tao, Meng Wang, Yuxuan Cao, Yaqian Niu, Yuming Chen, Tangjun Jiang, Tingting Li, Liwei Zou, Fangbiao Tao, and Xiaoyan Wu.