“…In animal models, cytokine activation has produced depressive symptoms, a decreased hippocampal volume, and “sickness behavior” (Dunn, Swiergiel, & de Beaurepaire, 2005; Goshen et al., 2008; Lawson, McCusker, & Kelley, 2013). Immunotherapy with interleukin‐2 or interferon‐α is reportedly associated with cognitive impairment and a depressed mood as well as fatigue, sleep disturbances, irritability, and loss of appetite (Bonaccorso et al., 2001, 2002; Capuron, Ravaud, & Dantzer, 2001; Capuron et al., 2001; Dieperink, Willenbring, & Ho, 2000). Vaccines, which act as cytokine inducers, also cause a depressed mood in healthy individuals (Harrison et al., 2009).…”