Nicotine dependence and clinical expression of schizophrenia in a Croatian population

Cilj: Studije koje su istražile povezanost između kliničkih značajki shizofrenije i ovisnosti o nikotinu rezultirale su proturječnim rezultatima, a velik je broj istraživanja uključio samo muške pacijente u analizu. S obzirom na to da slične studije nisu provedene u našoj populaciji, ispitali smo pridonosi li i u kojoj mjeri ovisnost o nikotinu u pacijenata sa shizofrenijom u hrvatskoj populaciji dobi nastupa bolesti i težini kliničkih simptoma ocjenske ljestvice PANSS-a (engl. Positive and Negative Symptom Scale). Ispitanici i metode: U istraživanju je sudjelovalo 265 pacijenata (muškarci/žene: 140/125). Dob prve hospitalizacije u sklopu koje je postavljena dijagnoza shizofrenije uzeta je kao približna dob početka bolesti, a evaluacija PANSS psihopatologije provedena je u akutnoj fazi bolesti tijekom posljednje hospitalizacije. Pacijenti su podijeljeni u skupinu pušača, koji puše najmanje jednu cigaretu dnevno u periodu duljem od godine dana, i skupinu nepušača, koji nikada tijekom života nisu pušili. Rezultati: Ovisnost o nikotinu, pronađena u otprilike dvije trećine pacijenata (muškarci: 70,7 %, žene: 62,4 %) dvostruko je češće zastupljena u odnosu na opću hrvatsku populaciju. Vrijednosti simptoma PANSS psihopatologije nisu se znatnije razlikovale između pušača i nepušača, niti kod pacijenata, niti kod pacijentica (P > 0,05), dok je dob prve hospitalizacije pokazala značajnu povezanost s ovisnosti o nikotinu isključivo u pacijenata. Uočeno je da muškarci koji puše obolijevaju značajno ranije u odnosu na muškarce nepušače (25,3 ± 6,8 vs. 28,8 ± 9,3; F = 5,15, P = 0,025). Pušenje pridonosi dobi prve hospitalizacije u muških pacijenata s približno 4 % (β = -0,21; promjena multiplog R2 = 0,04; P = 0,024). Zaključak: Ovisnost o nikotinu pridonosi u manjoj mjeri ranijoj pojavi bolesti u muškaraca, ali nije povezana s težinom simptoma ocjenske ljestvice PANSS-a niti u pacijenata niti u pacijentica.Aim: Studies investigating the association between clinical features of schizophrenia and nicotine dependence have yielded contradictory results, and the majority of them included only male patients in the analysis. Since similar studies have not been performed in our population, we investigated whether, and to what extent, the nicotine dependence might contribute to age of onset and data of Positive and Negative Symptom Scale (PANSS) psychopathology, among schizophrenia patients in the Croatian population. Patients and methods: The study comprised 265 patients (males/females: 140/125). Age at first hospital admission, at which the diagnosis of schizophrenia was used, was determined as the age of onset, while evaluation of PANSS psychopathology was performed during an acute illness state at the time of last hospital admission. Smokers were defined as persons who smoked more than one cigarette daily for more than one year, and nonsmokers were defined as persons who never smoked in their life. Results: Nicotine dependence, revealed among approximately two-third of patients (males: 70.7%, females: 62.4%), is twice as frequent as in the general Croatian population. PANSS psychopathology scores did not differ significantly between smokers and nonsmokers, neither among males, nor among females (P > 0.05), while nicotine dependence was significantly associated with the age at first hospital admission only among male patients. It has been detected that male smokers had a significantly earlier onset when compared to male nonsmokers (25.3 ± 6.8 vs. 28.8 ± 9.3, F = 5.15, P = 0.025). The nicotine dependence contributed to the age at first hospitalization among male patients by approximately 4% (β = -0.21; multiple R2 change = 0.04; P = 0.024). Conclusion: Nicotine dependence may contribute, to a smaller extent, to an earlier onset among males, while it is not associated with severity of PANSS psychopathology neither among male, nor among female patients