Higher testosterone linked to increased suicide risk in depressed teenage boys

Higher testosterone levels in male teenagers suffering from depression are linked to an increased risk of suicidal thoughts and behaviors according to recent research. The findings suggest that blood tests evaluating hormone levels might one day help doctors identify which teenage boys are at the greatest risk of self-harm. The research was published in the journal BMC Psychiatry.

Rates of depression and suicide among teenagers have been climbing steadily over the past decade. The problem presents a major public health challenge because doctors currently lack objective biological markers to predict which young people are most likely to consider or attempt suicide. Medical professionals typically rely on interviews, questionnaires, and self-reported symptoms to assess safety. These subjective methods can sometimes miss hidden warning signs if a patient is reluctant to share their true feelings.

Researchers have long debated whether sex hormones might play a role in the biology of depression and suicide. Evaluating testosterone levels has produced mixed results over years of scientific inquiry. Many past investigations grouped adults and teenagers together or did not account for the drastic differences between male and female biology. Hormone levels naturally vary across a person’s lifespan, meaning a single average measurement across all ages can obscure important details.

Adolescence is a sensitive period marked by rapid physical development and the emergence of secondary sexual characteristics. During this time, the bodies of teenage boys experience vast increases in testosterone production. These sudden shifts can heavily influence emotional regulation. The developing teenage brain often experiences a mismatch in maturity between the prefrontal cortex, which controls logic and planning, and the limbic system, which processes emotions.

Poor emotional regulation can easily lead to impulsivity and aggression. Researchers suspect that high testosterone levels might interact with the developing adolescent brain in ways that increase impulsive behavior through heightened activity in the emotional centers of the brain. Han Wang of Capital Medical University in Beijing and a team of colleagues set out to explore this dynamic. They designed a study to see if testosterone levels could be linked to suicidal tendencies specifically in teenagers diagnosed with major depressive disorder.

The research team created a project using electronic health records from Beijing Anding Hospital. They gathered data on 1,227 teenagers between the ages of 10 and 19 who had been hospitalized for major depressive disorder from 2013 to 2020. The investigators excluded patients who had other conditions like schizophrenia or autism, severe physical illnesses, or issues with substance abuse. They divided the remaining teenagers into two categories based on whether they had expressed suicidal thoughts or engaged in suicidal behaviors at the time of their hospital admission.

The researchers collected demographic information, clinical histories, and the results of blood tests taken shortly after the patients arrived at the hospital. These blood tests provided a measure of each teenager’s serum testosterone levels. The scientists analyzed the data separately for male and female patients to account for natural differences in hormone profiles. They adjusted their mathematical models to balance out the effects of other variables like age, tobacco use, alcohol consumption, and the duration of the patient’s illness.

The health records revealed a clear pattern among the male patients. Teenage boys who displayed suicidal thoughts or behaviors had higher testosterone levels compared to boys who did not exhibit these tendencies. This correlation persisted even after the researchers accounted for other variables that might alter the results. The presence of higher testosterone pointed consistently toward an elevated risk for self-harm in the male demographic.

The results for female patients were entirely different. The researchers found no statistical difference in testosterone levels between girls who experienced suicidal ideation and those who did not. Female patients in the study were more likely overall to report suicidal thoughts compared to the male patients, but their testosterone levels did not relate to this risk. The researchers note that other hormones, such as estrogen and progesterone, might be more relevant for depression and emotional regulation in teenage girls.

The researchers point out that male suicide is frequently linked to extreme forms of inward-directed aggression and impulsivity. Medications that lower impulsivity and aggression have been shown to reduce suicide risk in the past. It is possible that elevated testosterone fuels this impulsivity pathway in young men. The researchers also noted that genetic variations affecting how testosterone crosses into the brain have been connected to suicide in prior scientific literature.

To ensure their initial observations were robust, the research team conducted a second round of analysis using a separate set of hospital records. This validation dataset included 579 different teenagers hospitalized for major depressive disorder between 2022 and 2023. The investigators applied the exact same criteria and statistical models to this new group of patients. They also incorporated body mass index data into the second analysis to evaluate whether a patient’s physical weight influenced the outcomes.

The second analysis completely backed up the results of the primary dataset. Once again, male teenagers with suicidal thoughts or behaviors exhibited higher testosterone levels than their peers who did not show suicidal tendencies. The correlation remained strong after adjusting for the new set of demographic variables. Just as before, the female patients in the validation group showed no relationship between their testosterone levels and suicidal behavior.

The study provides a detailed look at the biology of mental health, but the authors acknowledge several limitations. Because the research relied entirely on searching through past medical records, the scientists could only observe correlations. They cannot prove that high testosterone causes suicidal behavior. It is entirely possible that the severe stress of a suicidal crisis activates the body’s hormonal response, causing a sudden spike in testosterone production after the fact.

The scientists specify that their study only included teenagers who were experiencing depression severe enough to require hospitalization. The results might not apply to young people with milder forms of depression who receive treatment in outpatient clinics or at home. The study also did not account for lifestyle variables like sleep disorders or daily physical activity levels, which are known to alter a person’s natural hormone balance. The data also did not separate teenagers who only had thoughts of suicide from those who actually attempted suicide.

Future investigations will need to track groups of teenagers over an extended period to see if rising testosterone levels truly precede suicidal thoughts. Researchers also hope to measure hormone levels at multiple points during a patient’s recovery to monitor how these chemicals fluctuate as mental health stabilizes. For female patients, future studies could track the menstrual cycle and measure a wider array of hormones to map their specific biological risk factors. In the meantime, the study acts as a reminder that male and female depression may operate through very different biological pathways.

The study, “High testosterone levels associated with elevated suicidal risk in male adolescents with depression,” was authored by Han Wang, Nan Lyu, Juan Huang, Bingbing Fu, Lili Shang, Fan Yang, Ling Zhang, and Qian Zhao.