Loss of hippocampal neurogenesis due to prolonged alcohol exposure may contribute to depression-like behaviour observed in mice during protracted alcohol abstinence, and reversed by antidepressants (Stevenson et al. 2009). Alcohol-use disorders are frequently comorbid with depression and anxiety (Grant et al. 2004), and loss of hippocampal neurogenesis during prolonged alcohol dependence could also contribute to the high clinical comorbidity of depression and alcoholism. Finally, stimulation of hippocampal neurogenesis has been postulated as a therapeutic mechanism behind antidepressant actions (Duman & Monteggia, 2006; Malberg et al. 2000; Pittenger & Duman, 2008; Santarelli et al. 2003). Inhibition of hippocampal neurogenesis by chronic intoxication may therefore be speculated to prevent successful treatment of comorbid depression in patients with alcohol-use disorders, although antidepressant treatments may act through both neurogenesis-dependent and -independent mechanisms (Bjornebekk et al. 2009; David et al. 2009).
