MOOD AND PHYSIOLOGICAL-EFFECTS OF SUBCUTANEOUS NICOTINE IN SMOKERS AND NEVER-SMOKERS

This study compared the effect of subcutaneous nicotine injections (2 x 0.3 mg and 2 x 0.6 mg) with saline on subjective and physiological m easures in 18 never-smokers and 18 smokers (24-h nicotine deprived), u nder conditions of rest and cognitive testing. Prior to the injections the mood of the smokers bad deteriorated to a level significantly bel ow that of the never-smokers as a result of tobacco withdrawal. Cognit ive tests caused reductions in calmness and increased alertness but th ere was no evidence of nicotine improving mood in either group under e ither condition. The 0.6 mg dose worsened mood in never-smokers and ca used unpleasant symptoms (e.g. dizziness and arm pain) in both groups. Compared with smokers, never-smokers experienced stronger symptoms of nicotine toxicity and a greater reduction in alertness in response to the 0.6 mg dose, suggesting chronic tolerance to some nicotine effect s in smokers. Nicotine produced similar increases in heart rate and de creases in finger pulse volume in both groups. Our results imply that if nicotine has a mood enhancing effect it occurs only after tolerance has been acquired to its primary adverse effects, and that its abilit y to reverse the mood deterioration caused by tobacco withdrawal is su sceptible to situational factors such as our experimental conditions. (C) 1997 Elseveier Science Ireland Ltd.