Scientists Discover How Psychological Trauma and Genetics Influence Smoking Habits
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25.08.2026 21:41
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2 min read
Researchers from the Harvard T.H. Chan School of Public Health examined how genetic predisposition and stress jointly shape nicotine addiction. According to a study published in Translational Psychiatry, severe psychological trauma drives smoking most strongly in individuals with a low innate genetic risk.
The study sample included 2,973 adult patients admitted to emergency departments following traffic accidents or physical assaults.
Study Methodology and DNA Evaluation
Scientists collected DNA samples from participants within the first 72 hours following the incidents and calculated individual polygenic risk scores for tobacco and alcohol use—a cumulative measure combining hundreds of minor genetic markers.
Eight weeks later, clinicians recorded the severity of post-traumatic stress disorder (PTSD) symptoms, and after six months, they evaluated actual tobacco and alcohol consumption.
On average, high genetic risk was associated with roughly a 14% increase in smoking intensity. However, when combined with stress factors, the authors observed an unexpected non-linear reaction.
The Antagonistic Effect of Stress and Genetics
According to data reported by PsyPost, biological risk and trauma do not simply add together:
- In participants with a high genetic predisposition, the severity of PTSD symptoms had virtually no impact on smoking frequency—their habits remained consistently high;
- In patients with a low genetic risk, the onset of intrusive memories, anxiety spikes, and nightmares triggered a sharp increase in tobacco use.
No similar correlation was found for alcohol: the genetic risk score for alcohol consumption showed no reliable link to the trauma experienced.
Limitations and Practical Applications
The authors emphasize that DNA does not dictate behavior: within the sample, the genetic model accounted for less than 1% of the variance in tobacco consumption.
The findings point to a “self-medication” mechanism: when facing traumatic events, people without an innate genetic urge for nicotine are more likely to turn to cigarettes as a quick way to relieve emotional stress, highlighting the need for targeted psychological support in the initial months following trauma.
