Smoking rates among those attending AOD treatment are high, ranging between 48-94% [215–217]. People with AOD and mental health conditions also smoke substantially more cigarettes per day, and are more likely to be nicotine dependent, than the general population [218]. Despite tobacco accounting for the highest rate of mortality among people with AOD and mental health conditions, the focus of AOD treatment has primarily centred on substances other than tobacco [219, 220]. There can be a reluctance to address smoking by AOD workers due to the belief that doing so might exacerbate other AOD use [221], and increase psychiatric symptoms and aggression [209, 222]. However, this view is not supported by the evidence [223]. On the contrary, smoking cessation is associated with improvements in depression [224, 225] and anxiety [226] when integrated into a treatment plan for mental disorders. Three Cochrane reviews have examined the evidence relating to the treatment of nicotine dependence in schizophrenia [227], depression [228] and AOD use disorders [229]. The findings indicate that rates of smoking abstinence were increased by the use of bupropion among people with schizophrenia without threat to their mental health [227]; the inclusion of a psychosocial mood management component to standard smoking cessation treatment among people with current and past depression [228]; and the inclusion of pharmacotherapy (nicotine replacement therapy [NRT], bupropion, varenicline, naltrexone, or topiramate), with no effects on other AOD use (alcohol, opioids, stimulants, cannabis [229]).
Compounds found in tobacco smoke have been shown to increase the rate at which some psychiatric medications are metabolised, by activating particular enzymes involved in the metabolism of those medications [230, 231]. For people who smoke cigarettes while being treated with some psychiatric medications, including olanzapine and clozapine, the increase in metabolism means blood concentrations of these medications are decreased. Differences in the metabolism rates of some psychiatric medications between those who smoke and those who do not smoke, have implications for the required therapeutic dosages of these medications. A meta-analysis examining the effect of smoking on the concentration to dose ratio of olanzapine and clozapine found daily doses for each should be reduced by 30% and 50% respectively, for people who do not smoke compared to people who smoke [230].
Smoking cessation in the context of an AOD or mental disorder may mean that a person can reduce their psychiatric medication. Crucially, the changes in metabolism associated with reducing or stopping smoking can result in toxic or even fatal levels of clozapine or olanzapine [230–232]. As differences in olanzapine and clozapine blood levels between people who smoke and people who do not smoke are triggered by tobacco smoke, NRT – while useful in managing symptoms of nicotine withdrawal – cannot counteract the effect [231]. Given the potential for toxicity, it has been recommended that doses of olanzapine or clozapine be reduced by 30-40% three to five days after stopping smoking, with close ongoing monitoring of blood concentration [231, 232].
Other substances that may be impacted by changes in metabolism from reducing or stopping smoking and warrant dose reductions following smoking cessation include [233]:
- Benzodiazepines.
- Beta blockers.
- Caffeine and alcohol.
- Chlorpromazine.
- Clopidogrel (consider use of alternative among people who do not smoke, e.g., prasugrel or ticagrelor).
- Flecainide.
- Fluvoxamine.
- Haloperidol.
- Heparin.
- Imipramine.
- Insulin.
- Methadone.
- Theophylline.
- Warfarin.
NRT can be used to minimise the physiological symptoms of nicotine withdrawal, and is available in patches, gum, inhalers, lozenges, and microtabs [234]. NRT is not recommended without a clinical assessment, or as a first-line treatment for AOD clients who [235, 236]:
- Are pregnant or likely to become pregnant.
- Are currently breastfeeding.
- Have significant cardiac or active vascular disease.
- Have nicotine sensitivities or allergies.
Clinicians managing clients on NRT should regularly monitor clients’ withdrawal to tailor the NRT dose, and address triggers, cravings, and stress through accompanying psychosocial interventions. For example, Baker and colleagues [237] provided up to 24-weeks supply of NRT to Australians who both smoked tobacco and were diagnosed with a psychotic disorder. NRT was accompanied by feedback provided to each participant on their smoking and levels of dependence, and a case formulation developed with participants, focusing on individual risk factors for CVD, utilising a MI approach and CBT strategies. The study found that both NRT plus a telephone-based intervention for smoking cessation (focused on monitoring smoking and discussing CVD risk factors) and NRT plus an intensive face-to-face healthy lifestyles intervention were effective in reducing smoking among people with severe mental health disorders. A follow-up study similarly found that both interventions were effective in maintaining rates of reduced smoking 36-months post-intervention [238]. There is also evidence that combination NRT (i.e., the use of more than one type of NRT together, such as patches and gum) and NRT containing higher doses of nicotine, are more effective at improving abstinence from smoking than single-form and lower doses, respectively [239].
Promising findings have arisen from a recent Australian RCT investigating the effects of an integrated smoking cessation program, consisting of routine screening, assessment, treatment for smoking (involving psychoeducation, quit kits/plans, NRT, regular feedback about progress, post-discharge management), and smoking-cessation training for staff into existing AOD services. Compared to those attending AOD services without the smoking cessation program, clients who received the 12-week program reported a reduction in the average number of cigarettes smoked per day at eight-week follow-up [240].
Despite evidence to suggest that smoking can be effectively addressed in clients of AOD and mental health services, there have been inconsistencies with the implementation of smoking interventions in practice. For example, a greater number of AOD staff smoke in comparison to the general population, and sometimes smoke with clients in order to promote a therapeutic relationship [221, 241, 242]. Higher rates of staff smoking with clients in AOD services are associated with lower intentions to quit among clients [241]. Negative attitudes among treatment staff towards smoking cessation have been acknowledged as potential barriers to effectively targeting nicotine dependence [243], with AOD staff rating treatment for smoking as less important than treatment for other AOD use [220], and with staff who smoke themselves less likely to initiate smoking cessation among clients, and be less successful when they do [244, 245].