Hi Gavin , I have read your question, Lungs Are one of the most vital organs for survival . The respiratory system once affected leads to deterioration of other systems as well.Smoking is the best way to spoil your lungs and hence your health. Yes , smoking is quite injurious to health . I would rather suggest you to quit smoking. Smoking or consuming nicotine is a kind of physical and physiological addiction , where our body once gets used to does not let us stop it . Smoking done at a high rate (many times) could be quite injurious to health in many ways and depression ,nausea , tiredness are its withdrawal symptoms.So i would suggest you to reduce smoking and eventually stop it for a good health. Citalopram is an anti depressant drug , and it should be taken under monitoring and guidance of an medical expert . Over dosage of this drug may lead to may health issues be it from digestion to reproductive issues. Hence please make sure that the dosage has to be carefully monitored. I recommend you to eat healthy food (thiamine rich with B complex)like Leafy vegetables,oats etc. , increase interaction with people , and practice meditation as well. If you experience any further issues i recommend you to consult an physician immediately. I hope you get well Soon, Dr.G.Gayatri Devi