Tobacco smoking in persons with schizophrenia followed up at a teaching hospital in Sri Lanka

Abstract

Background Studies in Western populations indicate that the prevalence of smoking in patients with schizophrenia ranges from 70-90%. Data from low and middle income countries is sparse. Aims To determine the prevalence of smoking in patients with schizophrenia, and to identify probable associations. Methodology The study was conducted at the psychiatry outpatient clinics of Colombo North Teaching Hospital, Ragama. Consecutive outpatients who met ICD-10 diagnostic criteria for schizophrenia were invited to answer an interviewer administered, pre-tested questionnaire on socio-demographic status, smoking habits, disease and treatment related characteristics. The Fagerstrom’s Test for Nicotine Dependence was used to grade the level of nicotine addiction. Results Of the 400 patients with schizophrenia, 171 (42.8%) were smokers. Of them 150 (87.7%) were dependent on nicotine. In terms of Fagerstrom’s Test, high dependence was seen in 3.3% ( n =5) while 39.2% ( n =59) and 57.3% ( n =86) reported moderate and low dependence respectively. All the smokers were male. For a majority of the patients the age of initiation of smoking was between 16-25 years, correlating with the onset of schizophrenia. Interestingly, most of the smokers (63.2%) were keen to quit smoking. Participants who smoked were significantly more likely to misuse other substances ( p =0.001) and to suffer from physical illnesses ( p =0.0001), compared to non-smokers. Smokers were also significantly more likely to be on intramuscular depot antipsychotics ( p =0.032), whereas non-smokers in contrast, were more likely to be on atypical antipsychotics ( p =0.0001). Conclusion A dual diagnosis of schizophrenia and nicotine dependence could be made in nearly half of our study population with schizophrenia. Although these rates are lower than in western populations, it is an issue that needs to be addressed in the treatment. DOI: http://dx.doi.org/10.4038/sljpsyc.v5i2.7816 Sri Lanka Journal of Psychiatry Vol 5(2):19-23