Genetically engineered mouse models in which Gabra2 expression or sensitivity to modulation has been altered (knock-out and knock-in) suggest a role for GABA-A receptors containing the α2 subunit in depression (Vollenweider et al., 2011), alcohol intake and behavioral response to alcohol (Boehm et al., 2004; Blednov et al., 2011, 2013; Liu et al., 2011), anxiety (Dixon et al., 2008), and cocaine-conditioned reinforcement and behavioral sensitization (Morris et al., 2008; Dixon et al., 2010). The gene discussed is GABRA2; the disease is major depressive disorder.