The results support the hypothesis that chronic exposure to tobacco smoke is an additional risk factor for suicide that is ameliorated by smoking cessation or reduced in those who are able to quit (Miller et al. 2000b; Hughes, 2008; Covey et al. 2012). A causal biological relationship between tobacco smoking and suicide is plausible. Neurocognitive and neurobiological evidence implicate chronic tobacco use in structural and functional abnormalities in brain reward networks implicated in suicide (Durazzo et al. 2010; van Heeringen & Mann, 2014). Nicotine exposure alters synaptic plasticity throughout the striatum, amygdala and hippocampus, a process that reversibly affects neurobiological processes broadly (Levine et al. 2011; Huang et al. 2013; Kandel & Kandel, 2014).
