Recent research in Acta Psychiatrica Scandinavica revealed that people who smoked were at 258% increased risk to experience hospital admittance due to such mental conditions as schizophrenia, bipolar disorder, or major depression.
For their study, the researchers took data on more than 330,000 participants from the UK Biobank. They calculated participants’ polygenic risk scores for traits including ever-smoking, smoking duration, and neuroticism (a tendency toward negative emotional states).
Their analysis has shown that the risk for hospitalization from mental illness was highest for current smokers and lowest for people who had never smoked. The risk was moderately higher for people who had previously smoked than those who had never smoked.
The researchers write in their paper: “Genetic liability for smoking intensity has a crossover effect on hospitalization for major depression, bipolar disorder, and schizophrenia. Smoking behaviors have the same magnitude of effect on mental health hospitalization as genetic liability.”