Concerns that the tobacco quitting drug varenicline (Champix) is associated with an increased risk of suicidality and accidents have not been supported by a large observational study.

Researchers from Sweden and Oxford in the UK looked at the records of over 69,000 individuals in Sweden who were prescribed varenicline between 2006 and 2009.

They found no evidence for a causal association between varenicline and the incidence of criminal offending, suicidal behaviour, transport accidents, traffic offences, and psychoses.

However, a small increased risk of mood and anxiety conditions during periods of varenicline treatment was found in people with pre-existing psychiatric disorders, the Swedish and UK researchers reported in the BMJ. 

This particular finding needed to be backed up by other studies, the researchers concluded.