Schizophrenia and other psychotic disorders

Many people with schizophrenia smoke, and their unique smoking behaviors have led scientists to believe that nicotine, the addicting substance in tobacco, may represent a form of self-medication, normalizing some central nervous system deficits involved in the disorder.


                The term psychotic disorder encompasses a wide variety of disorders that are characterized by having psychotic symptoms as the defining feature.1 Disorders that have psychotic symptoms, but not as the defining feature, are not included in this definition. The most commonly accepted definition of psychosis pertains to delusions and hallucinations, with the hallucinations taking place without logical reasoning or insight into their pathological nature.1 In general, schizophrenia receives a lot of attention from the media as well as researchers so it is no surprise that the term psychotic disorder is closely associated with schizophrenia in the general population. Despite this association, there is a clear distinction that schizophrenia is a specific type of psychotic disorder.

Other examples of psychotic disorders include:

  • Schizoaffective disorder
  • Schizophreniform disorder
  • Delusional disorder
  • Brief psychotic disorder
  • Shared psychotic disorder
  • Psychotic disorder due to a general medical condition
  • Substance-induced psychotic disorder
  • Psychotic disorder not otherwise specified

                Schizophrenia is the most common psychotic disorder in the population, as well as the most at risk to smoke. Schizophrenia is a mental illness that can strike at any time though it is most common in late adolescence or early childhood.1 Characteristic symptoms are grouped into two broad categories of positive and negative symptoms.

Positive symptoms reflect an excess or distortion of normal functions such as:

  • Delusions
  • Hallucinations
  • Disorganized speech.

In contrast, negative symptoms reflect an absence or diminution of normal functions such as:

  • Limited range in emotional expression
  • Decrease in goal-oriented motivation
  • Seemingly loss of happiness (e.g. depression).2

Signs and symptoms of the disorder vary from individual to individual, although all people with the disorder have one or more of the above symptoms. However, no single symptom is singularly representative of schizophrenia as the diagnosis involves recognition of a constellation of markers indicative of impaired occupational or social functioning.2

Schizophrenia and Smoking

                Forty-two studies across twenty nations consistently recognized an association between schizophrenia and smoking. 3 This association has relatively consistent strength across different cultures suggesting the association may have a biological component that manifests itself despite the presence of cultural factors associated with smoking behavior. Almost all of those studies found significant increases in heavy smoking and high nicotine dependence in people diagnosed with Schizophrenia compared to the general population.3 Compared to the general population, those with Schizophrenia have:

  • Smoking rates almost four times as high (22% vs 80%).4
  • Two-fold higher risk for coronary heart disease.5
  • Three-fold higher risk for cardiovascular death.6
  • Lower life expectancy by 20 percent.5
  • A five times greater chance of initiating cigarette use on any given day.3

With such alarming statistics, cigarette smoking has become a major health concern for this patient population for multiple reasons.  Within this subset of the population, smokers with schizophrenia:

  • Are the first age group to significantly display a relationship between smoking and increased mortality.6
  • Who smoke more than a pack a day have a 170% increased absolute mortality risk than nonsmokers.6
  • Have a 12-fold increased risk of cardiac related mortality than non-smokers.6

Compounding the problem is the fact that patients with schizophrenia spend up to 30% of their monthly budget on tobacco products.5 Losing roughly a third of their income will put extra stress on the patient and their family due to rising medical costs of both their psychotic disorder as well as their smoking related health issues.

There are numerous notable studies attempting to identify the theoretically strong link between schizophrenia and smoking that focus on the negative symptoms of the disorder. The negative symptoms associated with schizophrenia are well documented, though whether they are already present in patients or develop in response to antipsychotic drugs is yet to be determined. The prevailing theory in the field is that:

  • Certain properties of antipsychotic drugs block postsynaptic dopamine D2 receptors in the brain’s neurons.4
  • The blockage leads to an increase of negative symptoms such as social withdrawal, lack of motivation and depression.4
  • Smoking helps restore the blocked dopamine effects through the central action of nicotine on dopaminergic neurons.4

In essence, patients smoke cigarettes to help alleviate the undesirable negative symptoms. Additionally, research demonstrates that smoking for persons with schizophrenia is continuously reinforced because it is associated with socialization, relaxation, and a perceived means for coping with stress.7 This could justify the significantly lower cessation rates for patients with Schizophrenia compared to the general world’s population (9% vs. 14-49%).3,4

        Cigarette smoking is the most common preventable cause of morbidity and premature mortality in the United States6 and is known to be associated with the three leading causes of death in people diagnosed with Schizophrenia.4,5,6 Learning about the underlying relationship between psychotic disorders such as Schizophrenia and cigarette smoking is crucial to the development of effective smoking cessation treatment programs for this high risk population.








  1. Schizophrenia. (n.d.). Retrieved October 19, 2011, from Johns Hopkins Medicine website:
  2. American Psychiatric Association. (2000). Diagnostic and statistical manual of mental disorders (4th ed., text rev.). Washington, DC: Author
  3. de Leon, J., & Diaz, F. J. (2005). A meta-analysis of worldwide studies demonstrates an association between schizophrenia and tobacco smoking behaviors. Schizophrenia Research, 76(2-3), 135-157
  4. Ziedonis DM, Guydish J,Williams J, Steinberg M, Foulds J. 2006. Barriers and solutions to addressing tobacco dependence in addiction treatment programs. Alcohol Res. Health 29(3):228–35.
  5. Winterer, G. (2010). Why do patients with schizophrenia smoke? Current Opinion in Psychiatry, 23(2), 112-119.
  6. Kelly, D. L., McMahon, R. P., Wehring, H. J., Liu, F., Mackowick, K. M., Boggs, D. L., Dixon, L. (2011). Cigarette smoking and mortality risk in people with schizophrenia. Schizophrenia Bulletin, 37(4), 832-838.
  7. Van Dongen, CJ. 1999, Smoking and persistent mental illness: An exploratory study, Journat of Psychosociat Nursing 37 (11): 26-34.