Rökning ökar risken för schizofreni och depression

Här finns studien beskriven:
https://ash.org.uk/wp-content/uploads/2022/06/Causal-effect-smoking-and-mental-health.pdf
Conclusions
Overall, there is evidence to suggest a detrimental causal effect of smoking on mental illness, in
particular for schizophrenia. This body of evidence provides support for public health policies
surrounding tobacco control, especially those aimed at individuals with a high risk for or with
existing mental illness. Smoking cessation interventions for individuals with severe mental
illness certainly do not worsen mental health symptoms and may improve them in the long
term.

"A 2003 study of over 50,000 Swedish conscripts found that there was a small but significant protective effect of smoking cigarettes on the risk of developing schizophrenia later in life.[10] Many people with schizophrenia have smoked tobacco products long before they are diagnosed with the illness, and a cohort study of Israeli conscripts found that healthy adolescent smokers were more likely to develop schizophrenia in the future than their nonsmoking peers."
https://en.wikipedia.org/wiki/Schizophrenia_and_tobacco_smoking

Ja det är ju lite underligt att rökning tycks utöva en skyddande effekt vid en viss ålder och statistiskt signifikant verkar minska ned risken att drabbas av schizofreni senare i livet. Har inte sett en vettig förklaring på det orsakssambandet.

https://ajp.psychiatryonline.org/doi/full/10.1176/appi.ajp.161.7.1219

Tidigare data verkar ju säga tvärtom, dvs att rökning vid 18 års ålder tenderar till att minska ner förekomsten av schizofreni rent statistiskt. Enligt ett stort statistiskt underlag.