TOBACCO AND SCHIZOPHRENIA

Mini Lecture 3Module: Tobacco and Mental Health

Objectives of the Mini Lecture

GOAL OF MINI LECTURE: Provide students with knowledge on the association between tobacco and schizophrenia.

LEARNING OBJECTIVES Learners will be able to:• To describe the burden of schizophrenia, and its

association with other chronic diseases• To illustrate the biological, psychological and social factor

associated with tobacco use in schizophrenia patients• To mention how cessation can be addressed in clinical

management of schizophrenia patients.

CORE SLIDES

Tobacco and SchizophreniaMini Lecture 3Module: Tobacco and Mental Health

The Burden of Schizophrenia

• Schizophrenia is one of the most common psychiatric illnesses being treated. Patient can exhibit positive and negative psychotic symptoms leading to social and occupational dysfunction for at least 6 months.

(Ziedonis et al., 2008)

• Global burden of schizophrenia:– Median incidence: 15.2 per 100,000 population– Median prevalence: 460 per 100,000 population– Median lifetime morbid risk: 720 per 100,000 population– Median standardized mortality ratio of all cause: 2.6

(Eaton et al., 2008)

Schizophrenia and Chronic Diseases

Schizophrenia patients have poorer health care, higher burden of NCD risk factors and NCD premature deaths than the general population. – Schizophrenic have 20% shorter life expectancy– Common NCD risk factors in schizophrenic: smoking,

obesity and dyslipidemia, hypertension, insulin resistance, diabetes, sedentary life style, poor nutrition

– 2/3 of schizophrenia patients died of CVD vs. half of general population

– High burden of respiratory diseases due to smoking.

(Hennekens et al., 2005; Ziedonis et al., 2008)

Smoking in schizophrenia patients

Results from 42 studies in 18 countries showed that:• Smoking in schizophrenic patients is six times more

common than in general population (prevalence 70-85%) • More common in male patients (OR 7.2 in male vs. 3.3 in

female)• 50% smoked more than 25 cigarettes per day• Schizophrenic patients typically puffs more and deeper when

they smoke, thus they have a higher level of nicotine and cotinine.

• Quitting rate: 9% in schizophrenia patients vs. 14-49% in general population.

(de Leon and Diaz, 2005)

Tobacco use and schizophrenia

• A complex interaction between biological, psychological, and social factors in the association between tobacco use and schizophrenia.

– Biological factors: nicotine improves sensory gating and visuospatial working memory

– Psychological factors: patients used tobacco and its perceived positive effects for self-treatment

– Social factors: cigarettes used in social exchange and as form of bonding - main barrier in promoting smoking cessation in mental health institutions

(Ziedonis et al., 2008)

Treating tobacco addiction in schizophrenia patients

• Cessation is better achieved in patients with higher motivation to quit and lower level of tobacco dependence

• Combination of psychosocial treatment improves chances that patients will quit.

• The Polycyclic aromatic hydrocarbons (PAH) in cigarettes affects the metabolisms of antipsychotic drugs, therefore the medication has to be closely monitor during and after quitting.

(Fagerstrom and Aubin, 2009; Ziedonis et al., 2008)

Schizophrenia treatment can influence tobacco dependence

• Typical antipsychotic (ex. haloperidol) increases smoking

• Atypical antipsychotic (ex. clozapine) reduces smoking significantly in heavy smokers. (San et al., 2007; Ziedonis et al., 2008)

• Clozapine is the only atypical antipsychotic which has 5HT3 receptor antagonist activity and can improve P50 gating.

• Alpha-7 nicotine receptor (α7) agonist agent (ex. DMXB-A) improves memory, P50 response, and attention. α7-agonist is more potent and have slower decreasing response than nicotine. (Ziedonis et al., 2008)

OPTIONAL SLIDES

Tobacco and SchizophreniaMini Lecture 3Module: Tobacco and Mental Health

Tobacco use and schizophrenia: the biological factor

• Nicotine improved deficit in auditory sensory gating, led to better filter to distracting stimuli and better focus attention, and ultimately improving cognitive function.

• Nicotine improved visuospatial working memory, led to better visualization of relative positions of items.

• Improvement of visuospatial working memory is related to prefrontal cortical dopamine activity. Activation of anterior cingulated and bilateral thalamus improves visuospatial working memory.

(Ziedonis et al., 2008)

Tobacco use and schizophrenia: the psychosocial factor

• Schizophrenia patients perceived a lot of positive effects of smoking, and smoking is used as self-treatment of psychological symptoms. It has tremendous costs on patient’s health

• There are many social factors in schizophrenia patients that leads to a higher risk of smoking and tobacco use in the group of population.

(Ziedonis et al., 2008)

Smoking and anti-psychotic treatments

• Schizophrenia patients who smoke experience less extra pyramidal symptoms and other antipsychotic drug side-effects misuse of nicotine as self-medication

• Polycyclic aromatic hydrocarbons (PAH) in tobacco smoke can induce P450 1A2 isoenzyme, and affects the metabolism of antipsychotic medications (olanzapine, clozapine, haloperidol, and fluphenazine)

• Induced P450 1A2 isoenzyme leads to lower blood levels of antipsychotic medications among smoker.

• Increased antipsychotic side effects are therefore should be monitored during smoking cessation treatment.

(Ziedonis et al., 2008; Green, 2005)

Cessation medication in schizophrenia patients

• Combination of atypical schizophrenia treatments and nicotine dependence treatments – Buproprion: help reducing smoking and expired air CO– Nicotine patch: safe, well-tolerated, short long-term

abstinence than expected– Nicotine nasal spray: short-term reduction in

schizophrenia symptoms and impaired cognition

• There is very limited data about the effects of smoking cessation treatment in schizophrenic patients.

(Fagerstrom and Aubin, 2009; Ziedonis et al., 2008)