Reducing nicotine content in cigarettes may decrease their addiction potential in vulnerable populations, a study suggests.
Researchers at University of Vermont in the US examined the addiction potential of cigarettes with reduced nicotine content in two vulnerable populations of smokers - individuals with psychiatric disorders and socioeconomically disadvantaged women.
"Evidence in relatively healthy and socially stable smokers indicates that reducing the nicotine content of cigarettes reduces their addictiveness," said Stephen Higgins, Professor at University of Vermont in the US.
"Whether that same effect would be seen in populations highly vulnerable to tobacco addiction was unknown," Higgins added.
The team studied 169 daily smokers, including 120 women and 49 men. A total of 56 of the participants were diagnosed with affective disorders, 60 with opioid dependence, and 53 were socioeconomically disadvantaged women.
Each study participant completed 14 two to four hour sessions, abstaining from smoking for six to eight hours before each of the sessions, which were organised in three phases.
Phase 1 included sampling of the research cigarettes in double-blind conditions, beginning with the smoking of the participant's regular brand cigarette and then smoking one research cigarette of identical appearance, but varying doses of nicotine in sessions two to five.
A Cigarette Purchase Task (CPR) was completed after each smoking session to measure the effects of cost on the participant's rate of smoking. Additional questionnaires assessed research cigarette evaluation, nicotine withdrawal, smoking urges, and nicotine dependence.
Phase 2 sessions asked participants to select which cigarette they preferred to smoke among six different dose combinations and used a computer programme, which recorded which of the two cigarettes participants preferred for that session and whether they wanted to continue to smoke after two puffs or abstain.
The final phase 3 followed the same protocol, but measured only the highest and lowest doses of nicotine.
While participants tended to prefer the higher nicotine dose content research cigarettes, the team found that the low-nicotine dose cigarettes could serve as economic substitutes for higher-dose commercial-level nicotine cigarettes when the cost of the latter was greater.
"This study provides a very encouraging indication that reducing the nicotine content of cigarettes would help vulnerable populations," Higgins said. The study was published in the journal JAMA Psychiatry.