The scientists conducted parallel studies in human volunteers and non-human primates to investigate the differential effects of tobacco and nicotine smoking on changes in GABA(A) receptor availability during acute and prolonged alcohol withdrawal.
They report that alcohol withdrawal with or without concurrent tobacco smoking/nicotine use resulted in significant increases in GABA(A) receptor levels during the first week of withdrawal. After prolonged withdrawal, GABA(A) receptor levels returned to normal in alcohol-dependent nonsmokers, but alcohol-dependent smokers had significant and persistent increases in GABA(A) receptors associated with craving for alcohol and cigarettes.
These data suggest that constituents of tobacco smoke other than nicotine block recovery of GABA(A) receptor systems during sustained abstinence from alcohol, contributing to alcohol relapse and smoking maintenance.
Tobacco smoking interferes with GABAAreceptor neuroadaptations during prolonged alcohol withdrawal | Link to source | Found at Alkohol adé (german)