Confounding Bias
As an epidemiologist, it is essential to recognize the importance of confounding in research studies, especially when examining complex relationships, such as the association between cancer and exposures like alcohol and smoking, or the association of mental health and suicide.
Definition of Confounding
Confounding occurs when a third variable, called a confounder, is associated with both the exposure (e.g., alcohol or smoking) and the outcome (e.g., cancer) under study. This association can lead to a distorted estimate of the relationship between the exposure and outcome, making it challenging to determine the true effect of the exposure on the outcome.
Example of Confounding
In a study investigating the relationship between alcohol consumption and lung cancer, smoking could be a confounding factor. Smoking is associated with both alcohol consumption (exposure) and lung cancer (outcome). If not controlled for, the observed association between alcohol consumption and lung cancer might be partially or entirely because of smoking rather than alcohol itself.
Application of Confounding Model to Mental Health and Gender Dysphoria
Anxiety and depression, caused by factors ranging from genetics to social determinants of health, may be symptoms associated with major mental illnesses, such as depressive, or bipolar disorders. These symptoms may lead to suicide. Gender dysphoria is also associated with anxiety and depression, and therefore, its contribution to suicide may be confounded by its association with anxiety and depression. The directionality of gender dysphoria as the cause of depression and anxiety has not been proven.
The fact that suicide rates, as well as reported symptoms of anxiety and depression have continued to increase in population surveys — among teenage girls in particular — despite mitigating interventions to prevent stigmatization, argues against the currently prescribed causal relationship. Furthermore, the observed reduction in suicides in reported case series would need further assessment to rule out a temporary effect due to celebrity status.
Strategies to Control for Confounding Variables
- Study Design: Researchers can use matching or stratification in their study designs to control for potential confounders. Stratification in the analysis would achieve a similar purpose. However, the potential confounders would need to be considered in estimating the sample size of the study to count with enough observations in each stratum for a robust analysis.
- Statistical Analysis: Using multivariable regression models, researchers can adjust for confounders by including them as covariates in the analysis. This approach helps isolate the independent effect of the exposure on the outcome while accounting for potential confounding variables.
- Randomization: In experimental studies, randomization ensures that participants are assigned to exposure groups by chance, minimizing the likelihood of confounding. However, often this method is not always feasible, as it is not in this case, and we need to rely on observational studies. Given that, in this instance, recall bias of case-control studies would lead to an insurmountable bias, the cohort study design would be preferred.
In cohort study designs, researchers follow a group of individuals over time, tracking exposures and outcomes, and comparing the incidence of the outcome between exposed and unexposed groups. The cohorts under study are usually observed prospectively.
As of 2022, a systematic review of the publication-biased clinical literature about gender dysphoria and gender-affirming care would readily reveal that no well-designed cohort studies with clear and unambiguous exposure definitions, adequate study power, and sufficient period of observation have been conducted. Instead, case series and expert opinions have been presented as evidence to support standards of gender-affirming care with unproven claims of reversible effects.
The Reverse Causation Hypothesis of Abigail Shrier
Abigail Shrier’s Irreversible Damage: The Transgender Craze Seducing Our Daughters is a work that has ignited intense discourse and debate within the realm of transgender studies and beyond. The book primarily focuses on the recent surge in adolescent girls identifying as trans boys, attributing this not to gender dysphoria or transgenderism but to a social contagion fueled by peer influence and societal pressures.
Shrier’s book is undeniably well-researched and compassionate, providing a wealth of statistics, personal accounts, and expert testimonials to back her claims. She navigates through complex issues such as botched surgeries and the regret experienced by some individuals post-transition; topics that require careful handling given their sensitive nature. Her exploration of these areas is comprehensive, and she adds a significant contribution to the literature surrounding transgender youth.
Some data sources:
Another study
Analyzing survey responses of more than 84,000 people of all ages in Britain, the researchers identified two distinct periods of adolescence when heavy use of social media spurred lower ratings of “life satisfaction”: first around puberty — ages 11 to 13 for girls, and 14 to 15 for boys — and then again for both sexes around age 19.
For most adolescents in the United States, screens are a big part of life. Nine out of 10 American teenagers have a smartphone, and they are spending many hours a day staring at it — watching videos, playing games and communicating through social media, recent surveys show.
As social media use among teenagers has exploded over the past two decades, so too have rates of depression, anxiety and suicide, leading scientists to wonder if these striking trends could be related.
Some have suggested that social media may have an indirect effect on happiness by displacing other activities, like in-person interactions, exercise or sleep, that are crucial for mental and physical health. Heavy social-media use seems to disturb adolescent sleep patterns, for example.
Source: https://www.nytimes.com/2022/03/28/science/social-media-teens-mental-health.html
Causal Inference
In epidemiological research, an absolute criterion of causal inference is that the cause must precede the effect (outcome under study). There is ample evidence to suggest that: 1) a preexisting gender gap in anxiety/depression leading to self-harming behavior, 2) a differential effect of social media on teenage girls, and 3) gender dysphoria has historically been very rare and had occurred almost exclusively in males. The fact that we don’t see a similar surge of gender dysphoria among older cohorts of women suggests that social media may have exerted a causal role.
Conclusion
The available evidence suggests that Shrier’s hypothesis cannot be dismissed. Indeed, social media may be exerting a causal role in the gender dysphoria epidemic. Teenage girls are indeed more prone to anxiety and depression leading to self-harm than teenage boys since before the advent of social media. The gap between teenage girls and boys has significantly widened since then, and has been exacerbated by the COVID-19 pandemic. The anecdotal evidence and expert opinion, misconstrued as definitive scientific facts, may be confounded, as shown in model 2, and the warning expressed by Shrier should be seriously considered regardless of the current political polarization of this issue.
Rebuttal:
Abigail Shrier’s Irreversible Damage: The Transgender Craze Seducing Our Daughters presents a narrative that there’s a sudden surge in the number of teen girls identifying as trans boys due to social contagion rather than gender dysphoria or transgenderism. However, several points in her thesis can be challenged based on existing research and scientific understanding of gender identity.
- Transgender as a Social Contagion: Shrier posits that the rise in transgender identification among teenagers, particularly those assigned female at birth (AFAB), is a result of social influence or trend. This notion has been widely disputed by experts who argue that gender identity isn’t something that can be influenced by trends or peer pressure. The American Psychological Association (APA) asserts that being transgender is not a mental disorder and is a deeply held aspect of one’s identity.
- The Role of Mental Health: Shrier suggests that many young individuals who identify as trans might be struggling with other mental health issues, implying a causative link. While it’s true that transgender individuals may have higher rates of mental health issues, many studies indicate these are often due to societal prejudice, discrimination, and lack of acceptance rather than being intrinsic to being transgender.
- Regret After Transition: Shrier brings up cases of individuals regretting transition. While such cases do exist, they represent a small minority. A 2015 survey of over 28,000 people found that only 8% of respondents reported detransitioning, and 62% of those did so temporarily. The most common reason wasn’t regret but pressure from family, indicating societal factors play a significant role.
- Medical Interventions: Shrier expresses concern about medical interventions for transgender youth. It’s crucial to note that guidelines provided by professional organizations like the Endocrine Society and the World Professional Association for Transgender Health (WPATH) recommend a careful, staged approach. They advise using puberty blockers, which are reversible, to give adolescents more time to explore their gender identity.
- Rapid Onset Gender Dysphoria (ROGD): Shrier’s argument heavily relies on the concept of ROGD, a term that is not recognized by any major medical organization. The alleged condition suggests that social contagion is the reason for a sudden onset of gender dysphoria in adolescence. However, this concept has been criticized for its methodological flaws and lack of empirical evidence.
Commentary: Several inconsistencies are evident in this rebuttal. First, data are substituted by expert opinion. Second, the claim of causal directionality has not been proven. Third, the fluidity of gender identification is not consistent with a definitive assessment of regret. Fourth, the reversibility of puberty blockers has not been proven. Fifth, the lack of evidence is compounded by the censoring of studies contrary to established beliefs.
Historically, the paradigm shift from a geocentric to a heliocentric model of the solar system did not come about as a result of more data. It came about as a result of adopting a different model which did not contradict the evidence, but did contradict the dogmas of the epoch. We may be facing a similar situation today. The absolute reliance on self-reported gender identification, during such fluid time as adolescence, to apply nonreversible puberty blockers and other medical procedures in teenagers, may be seen in most (not all) cases as a misconstrued post-modern concept of the self, ignoring alternative and more rational models, such as Assagioli’s Psychosynthesis.
In a teenager confused and coached by social media influencers, who is advocating for a change in gender identity, the fluid personality of an immature conscious self, or the Higher (Transpersonal) Self?
Moreover, from an ethical perspective, a medical practitioner cannot apply a medical procedure on request from a patient without considering the four pillar of medical ethics.
References:
https://www.cdc.gov/healthyyouth/data/yrbs/yrbs_data_summary_and_trends.htm
Overall, the percentage of students reporting this behavior increased from 1999 to 2021. The direction of the trend line changed in 2015. There was no change, from 1999 to 2015. There was an increase from 2015 to 2021. Any indicated increase or decrease is statistically significant.
Prevalence of Mental Illness
Mental illness is fairly common among children and adolescents. In fact, approximately 22% of adolescents have a severe mental impairment, according to the National Alliance for the Mentally Ill. About half of all mental illness starts by the age of 14.2
https://www.verywellfamily.com/teen-mental-health-what-parents-need-to-know-2611247
Facts about children’s mental health from 2013–2019
During this period, the most common disorders diagnosed among U.S. children aged 3–17 years were ADHD and anxiety problems, each affecting more than 1 in 11 children:
o ADHD 9.8%
o Anxiety 9.4%
Depression and suicide were a risk for older children and teens:
o Among adolescents aged 12–17 years, 1 in 5 (20.9%) had ever experienced a major depressive episode.
o Among high school students in 2019, more than 1 in 3 (36.7%) reported feeling sad or hopeless, and nearly 1 in 5 (18.8%) seriously considered attempting suicide.
o About 7 in 100,000 children aged 10–19 years died by suicide in 2018 and 2019.
Mental disorders can begin in early childhood and affect children across a range of sociodemographic characteristics. Some populations are more affected due to social determinants of health such as poverty, access to education, and geographic area, resulting in health inequities.
Source: https://www.cdc.gov/childrensmentalhealth/features/understanding-public-health-concern.html
Vulnerable Teens
Adolescence is a critical period for mental, social, and emotional wellbeing and development. During adolescence, the brain undergoes significant developmental changes, establishing neural pathways and behavior patterns that will last into adulthood. 1
Because their brains are still developing, adolescents are particularly receptive to the positive influences of youth development strategies, social and emotional learning, and behavioral modeling. But adolescents’ developing brains, coupled with hormonal changes, make them more prone to depression and more likely to engage in risky and thrill-seeking behaviors than either younger children or adults. These and other factors underline the importance of meeting the mental, social, and emotional health needs of this age group.
Mental health and social and emotional wellbeing – combined with sexual and reproductive health, violence and unintentional injury, substance use, and nutrition and obesity – form part of a complex web of potential challenges to adolescents’ healthy emotional and physical development.
Facts about Adolescent Mental Health
• Approximately 20% of adolescents have a diagnosable mental health disorder.
• Many mental health disorders first present during adolescence.
• — Between 20% and 30% of adolescents have one major depressive episode before they reach adulthood.— For a quarter of individuals with mood disorders like depression, these first emerge during adolescence.— Between 50% and 75% of adolescents with anxiety disorders and impulse control disorders (such as conduct disorder or attention-deficit/hyperactivity disorder) develop these during adolescence.
https://www.cdc.gov/childrensmentalhealth/features/understanding-public-health-concern.html
The American College of Obstetricians and Gynecologists makes the following recommendations and conclusions:
• At least one in five youth aged 9–17 years currently has a diagnosable mental health disorder that causes some degree of impairment; one in 10 has a disorder that causes significant impairment.
• The most common mental illnesses in adolescents are anxiety, mood, attention, and behavior disorders.
• Suicide is the second leading cause of death in young people aged 15–24 years.
Source: https://www.acog.org/clinical/clinical-guidance/committee-opinion/articles/2017/07/mental-health-disorders-in-adolescents
[This analysis is work in progress. Created 2023.07.14]
José Becerra, MD, MPH, FACPM
Atlanta, GA and San Juan, Puerto Rico
Retired Centers for Disease Control Medical Epidemiologist
Adjunct Associate Professor of Epidemiology and Biostatistics
Graduate School of Public Health, Medical Sciences Campus
University of Puerto Rico