Smoking cessation and mental illness

According to the American journalist and author Fletcher Knebel: “It is now proved beyond doubt that smoking is one of the leading causes of statistics.” He is right, of course; the negative influence of tobacco products on almost every aspect of health is well established. Efforts to encourage smoking cessation among the general population have met with some success, yet it seems that individuals with significant mental health difficulties find it much harder to give up cigarettes. Of note, tobacco dependence is listed in its own right as a substance-misuse disorder in the <em>International Classification of Mental and Behavioural Disorders</em> (<em>ICD-10</em>). Technically, at least, it is the most prevalent form of substance abuse among people with mental illness, affecting 40-to-50 per cent of those with depression and up to 90 per cent of those with schizophrenia.

According to the World Health Organisation (WHO), individuals with schizophrenia have a reduced life expectancy of between 10 and 25 years. This is partly because heavy smoking is two-to-six times more common among people with schizophrenia, while 45-to-55 per cent are obese, 10-to-15 per cent have type 2 diabetes and 19-to-58 per cent are hypertensive. So why do so many people with mental illness smoke?

Various theories exist for schizophrenia, including that of Edward and colleagues, who refer to the dopamine release associated with nicotine and its consequent feelings of wellbeing, fewer negative symptoms and less severe extrapyramidal side-effects. A further theory (cited by Douglas and colleagues) suggests that smoking may help to place some vague structure on an otherwise disorganised daily routine, while a third supposes that individuals with schizophrenia simply find it more difficult to tolerate the symptoms of nicotine withdrawal.

Winterer cites nicotine’s associated increase in hepatic clearance that may diminish the side-effects of certain antipsychotics. He also notes an assertion that smoking might actually improve psychiatric symptoms (such as negative and cognitive symptoms), even though the underlying molecular mechanisms are not yet known. Either way, Winterer concludes that viewing heavy smoking in schizophrenia as just a ‘bad habit’ is somewhat simplistic.

On the contrary, it might help to explain why clinicians find it so difficult to convince their psychiatric patients to give up cigarettes. A Californian study by Prochaska and colleagues surveyed anonymously the attitudes of psychiatry residents in this regard. Over three-quarters of the sample believed their overall ability to assist their patients to give up smoking was either fair or poor. Most said they had received almost no training in such matters during medical school and residency, yet nearly all were interested in learning more about helping patients to give up tobacco.

If psychiatrists are willing to rise to the challenge, can the same be said for patients? Dickens and colleagues considered this question when they surveyed a group of forensic inpatients in Northampton, UK, almost 76 per cent of whom were smokers. Three out of every four participants thought cessation was too difficult to attain, citing impediments such as a smoky atmosphere on the ward and the fact that they could observe staff and other patients smoking.

The authors suggested that, in addition to regular help and encouragement for smokers to give up their habit, an overall change in attitude and culture was required. It also noted that professionals might consider whether their own smoking habits were undermining patients’ attempts to quit.

<h3><strong>Environment </strong></h3>

It seems, therefore, that environment may play a role. Shmueli and colleagues considered this in their study of attitudes to quitting in a smoke-free hospital. Although exempted from national tobacco bans, some hospitals in California went tobacco-free on a voluntary basis, with few reported difficulties in clinical management. In one such institution, smoking behaviour was assessed among 100 patients at various intervals of their treatment up to three months post-discharge. Even without smoking-cessation treatment, a smoke-free atmosphere was linked to an increased anticipation of successful cessation and a reduced expectation of difficulty in remaining abstinent, irrespective of diagnosis. These beliefs were, in turn, predictive of subsequent smoking behaviour.

Hehir and colleagues embarked upon a similar study in New South Wales. The authors conducted focus groups and inpatient surveys in a smoke-free forensic mental health facility and found that, while some 80 per cent reported having smoked prior to admission and 39 per cent said they were angry at being forced to quit, 42 per cent actively wanted to give up cigarettes and were glad of the opportunity. Three out of four patients ultimately reported that living in a smoke-free environment had a positive effect on their health, while 58 per cent remained non-smokers at post-discharge follow-up.

On a grander scale, Lawn and Pols conducted a review of 26 international studies of smoking bans in psychiatric inpatient settings. According to the authors, staff generally expected more smoking-related problems than actually occurred; specifically, there was no increase in levels of aggression, the use of seclusion, discharge against medical advice or the use of ‘as-required’ medication following smoking bans. Consistency, co-ordination and full administrative support were deemed essential, while nicotine replacement therapy was a widely-used strategy. Unfortunately, the authors found that many patients resumed smoking post-discharge, suggesting that inpatient smoking bans did not necessarily assist in longer-term abstinence.

<h3><strong>Doctors’ role</strong></h3>

So, what should doctors ideally be doing to help patients with mental illness quit smoking? In many ways, the approach does not differ from that taken with any patient, and is well described by the National Institute for Health and Care Excellence (NICE), in addition to other guidelines. The UK Centre for Tobacco Control Studies has produced a lengthy report on the effectiveness of smoking cessation interventions in mental health. The <em>Maudsley Prescribing Guidelines</em> naturally suggest that all patients should be encouraged to give up wherever possible, but bearing in mind that cessation can lead to low mood, anxiety, irritability and exacerbation of underlying psychiatric illness.

Medications include nicotine replacement and the noradrenaline-dopamine reuptake inhibitor bupropion. The latter is licensed for smoking cessation and can be used cautiously in many psychiatric patients. Noradrenergic antidepressants, such as nortriptyline and venlafaxine (but not selective serotonin reuptake inhibitors), may also work, according to the guidelines. Other pharmacological options include varenicline, a partial agonist of nicotinic alpha-4 and beta-2 receptors that is purported to work by relieving both cravings and withdrawal symptoms. At one stage, there were worries about its potential association with suicidal behaviour, but these early concerns do not appear to have been borne out in recent years. And let us not forget the rise in popularity of e-cigarettes.

In terms of psychotherapy, motivational enhancement techniques can be useful for helping patients to stop smoking. Motivational interviewing is based on a conceptualised model of the stages through which behavioural change occurs. As the individual moves through these stages of pre-contemplation, contemplation, preparation, action, maintenance and relapse, the appropriate treatment options are matched with their current motivational level and stage within the cycle.

<h3><strong>Effectiveness?</strong></h3>

So, do these interventions work? In 2013, Tsoi and colleagues updated their Cochrane systematic review of smoking cessation and reduction interventions among individuals with schizophrenia. Thirty-four randomised trials were included, seven of which compared bupropion to placebo and two of which compared varenicline to placebo. The meta-analysis revealed higher cessation rates with bupropion than with placebo at both the end of treatment and six-month follow-up. The authors could find no reports of major adverse events, such as seizures with bupropion. Similarly, smoking cessation rates with varenicline were significantly higher than placebo at the end of treatment, but the authors cited insufficient evidence to comment on six-month follow-up.

They found no significant adverse effects of varenicline on psychiatric symptoms but could not definitively rule them out. Finally, they reported that contingent reinforcement was a useful short-term behavioural measure, but cited little evidence to support other psychosocial or pharmacological measures in smokers with schizophrenia.

Similarly, Banham and Gilbody produced a review of smoking cessation in severe mental illness. The authors examined eight randomised, controlled trials and found that most pharmacological or psychological interventions yielded moderately positive results. In particular, the pooled results of five studies showed bupropion to be significantly better than placebo, while another study found the combination of behavioural support and nicotine replacement therapy to be significantly better than usual care, but only in the short term. The authors concluded that it was possible to treat tobacco dependence in people with severe mental illness using the same treatments that work in the general population. The authors also noted that treatment did not adversely affect mental state.

A word of caution is needed, however, because nicotine is a hepatic inducer. Lowe and Ackman studied the impact of smoking cessation on stable patients taking clozapine or olanzapine. They noted that, in smokers, clozapine and norclozapine concentrations are lower, while olanzapine appears to be cleared more rapidly. Thus, smokers require higher dosages than non-smokers. Similarly, smoking cessation may abruptly raise serum concentrations of these drugs to such a degree that dosage reductions of up to 40 per cent may be required. According to the authors, worsening of psychiatric symptoms, somnolence, hypersalivation, extreme fatigue, extrapyramidal side-effects and seizures have all been reported during this transition period.

<h3><strong>Relapse </strong></h3>

Finally, having successfully kicked the habit, are patients likely to relapse? Both systematic reviews above suggest some maintenance of cessation is possible at six months, with appropriate help. Not all studies agree, however. For example, Prochaska and colleagues examined the smoking habits of 100 psychiatric patients residing in a smoke-free unit. Nicotine patches were provided to 70 per cent of participants, but few received any sort of counselling and, in this context, the authors found that participants resumed their habit within five weeks of discharge.

As Fletcher Knebel says, perhaps it all boils down to the statistics. But the best evidence still supports the encouragement of all patients with mental illness to quit smoking for good.

<strong>References on request </strong>