Nicotine psychobiology: how chronic-dose prospective studies can illuminate some of the theoretical issues from acute-dose research.

RATIONALE: To illustrate how prospective cigarette smoking research can illuminate some of the theoretical dilemmas about nicotine psychobiology from acute dose research. METHODS AND
RESULTS: When briefly deprived smokers are administered nicotine, they display a range of psychobiological 'gains', with improved cognitive performance, feelings of contentment, and reduced feelings of stress or depression. However, abstinence leads to decrements in all these functions. The balance between the deficits of nicotine deprivation and the gains of reinstatement has been debated for decades. Yet, it still remains controversial whether nicotine is psychobiologically beneficial, neutral or detrimental. Some illumination may be provided by prospective research. Taking up smoking during adolescence is often followed by increased feelings of stress and depression, whereas quitting is often associated with subsequent mood gains. Short-term prospective studies reveal that the essence of nicotine dependency is repetitive psychobiological vascillation. The mood gains of smoke inhalation represent the temporary reversal of abstinence effects, and the frequent experience of negative states in between cigarettes explains why smoking can increase psychobiological distress. This may also be linked with Diathesis-Stress models. If withdrawal symptoms reflect the exacerbation of natural predispositions, then 'disadvantaged' smokers will suffer the worst abstinence symptoms and develop the strongest nicotine dependency. This explanation contrasts with the self-medication model, which focuses on the immediate benefits of smoke inhalation, rather than the overall costs of nicotine use.
CONCLUSIONS: The frequent experience of negative psychological states in between cigarettes helps to explain why nicotine dependency is associated with a range of psychobiological problems.