Depressed mood induction in early cigarette withdrawal is unaffected by acute monoamine precursor supplementation

BACKGROUND: Cigarette smoking is the leading preventable cause of death; however, quitting is difficult and early relapse is common. Dysphoric mood during early cigarette withdrawal is associated with relapse, and with the exception of bupropion and nortriptyline, few interventions have been developed to prevent this. During early cigarette withdrawal there is an elevation in the levels of monoamine oxidase-A (MAO-A), which removes monoamines excessively and induces oxidative stress and is implicated in creating sad mood. Hence, we conducted a randomized, placebo-controlled, double-blind crossover trial of a dietary supplement designed to counter the effects of elevated MAO-A levels on vulnerability to depressed mood. METHODS: Twenty-one otherwise healthy cigarette smokers completed the protocol, receiving either active dietary supplement followed by washout and placebo or the same in reverse order. The dietary supplement was composed of monoamine precursors (2 g tryptophan, 10 g tyrosine) and blueberry antioxidants (blueberry juice with blueberry extract). Vulnerability to depressed mood was measured by the change in scores of depressed mood on the visual analog scale (VAS) following the sad mood induction paradigm (MIP). RESULTS: There was a significant increase in VAS depressed mood scores after the sad MIP during supplement and placebo, but no difference between active and placebo conditions. There was also a significant increase in urge-to-smoke scores after sad MIP during supplement and placebo but no difference between active and placebo conditions. Reliability of the increase in VAS after MIP was very good. CONCLUSION: The dietary supplement had negligible effect on depressed mood, but sad MIP is a very reliable method that can be applied in future studies to assess other interventions for preventing dysphoric mood during early cigarette withdrawal.