Estimates suggest that at least two thirds of people living with schizophrenia smoke.¹ Exactly how many people smoke at any one point in time (the prevalence) ranges from around 60% to 90%.¹ This is very high considering that fewer than one fifth of adults in the general population are smokers.¹ Interestingly, smoking rates among people with schizophrenia appear to have been largely unaffected by public health campaigns and the introduction of smoking bans in public spaces in many countries.²
 
The link between smoking and chronic mental health conditions has been known for many years, and rates seem to be highest among those with schizophrenia.¹ Moreover, it’s been found that the more severe someone’s mental health condition is, the more likely it is that they smoke.^1,3 Indeed, some of the highest smoking rates have been recorded in people who have been hospitalized with a psychiatric disorder.³
 
Research suggests that, compared to the average adult, people with schizophrenia who smoke:^1,3,4

It is not clear why people with schizophrenia smoke more than others and are less likely to quit.¹ It has been the subject of a lot of research over the years and it is likely that there is a combination of factors involved.¹ For instance, smoking rates could be higher than in the general population because smokers believe that smoking helps to relieve their schizophrenia symptoms or ease the side effects of medications.¹ It could be that people are not ready or willing to quit, or perhaps they are simply not being offered the appropriate help to stop smoking.¹ There may even be a genetic predisposition for someone with schizophrenia to become dependent on nicotine.⁴
 
When it’s inhaled, nicotine is quickly absorbed into the bloodstream and stimulates the release of chemicals in the brain that are associated with pleasurable feelings, making smokers feel more relaxed.³ These feelings are often short-lived, however, and as the levels of nicotine wane, there is a desire to reach for another cigarette.³ This cycle of smoking and obtaining pleasurable feelings which then fade are thought to be more pronounced or perhaps dysfunctional in people with schizophrenia.³
 
Another factor that may influence smoking rates is a person’s socioeconomic status. People who are of a lower socioeconomic status – which is a measure of someone’s educational level, income and occupation – are known to be much more likely to smoke than those who are more affluent.⁷ Low socioeconomic status is also linked with having a higher risk of developing schizophrenia.⁸

Whatever the reason is for the higher rates of smoking in those with schizophrenia, smoking has many harmful effects and smokers should be encouraged to quit.^1,2
 
While there have been some reports of smoking having beneficial effects on specific schizophrenia symptoms, this is still being debated.^1,6 For instance, how well someone can think or understand information (i.e., cognition) had been shown to be both improved and delayed in people with schizophrenia who smoke.^1,3,6
 
Smoking may actually damage the brain by a process known as oxidative stress.⁹ This involves the production and accumulation of substances called reactive oxygen species which can interfere with how well cells are able to communicate with each other.⁹ Oxidative stress has been linked to the development of various health conditions including cancer, heart disease, as well as psychiatric illnesses.^9-11
 
Bear in mind that any ill-effects on mental health are in addition to the well-established risks of smoking on physical health. People who smoke are more likely to have, and to die prematurely from, heart disease, chronic obstructive lung disease, and lung cancer than people who do not smoke.²
 

People with schizophrenia already have a shorter life expectancy when compared to adults without mental illness in the general population.² Smoking is thought to be one of the biggest contributors to that excess mortality.²
 
Remember, schizophrenia is also associated with an increased tendency to carry excess weight, drink a lot of  alcohol and generally lead an unhealthy lifestyle, so adding smoking into this mix is harmful for the overall health of the individual.¹²
 
Smoking can also affect how well treatments for schizophrenia work.^1,2 How the body breaks down some of the antipsychotic drugs can be affected and therefore higher doses of these medications may be needed to have the same effect in people who smoke compared to those who don’t.^1,2 This increases the chances of them experiencing side effects.² Conversely, if doses of antipsychotics are lowered to counteract potential side effects, this could put the individual at greater risk for relapse and experiencing further episodes of psychosis.²  

You will find lots of resources online that offer help to quit smoking. While these may offer valuable advice, giving up smoking is not easy. It may be more difficult for someone with schizophrenia and therefore they may need professional help.
 
Thus, an important first step is to ask a doctor for advice on the available options to help in quitting.¹³ These options include various types of nicotine replacement therapies and tablets that help to reduce the cravings for nicotine as well as behavioural therapies.^4,13  Importantly, evidence suggests that these options for smoking cessation work just as well in people with schizophrenia as they do in anyone else who is motivated to give up smoking.⁴