HTR5A and sexual dysfunction: However, evidence in humans and rats suggests that acute treatments of SSRIs generally do not cause sexual dysfunction (Olivier et al. 2011; Waldinger et al. 2001, 2002); rather, SSRI-related sexual dysfunction is likely dependent upon delayed neurochemical adaptions following chronic, but not acute, elevation of 5-HT as well as modulations of neuroendocrine and other neurotransmitter systems (Clayton et al. 2013; Olivier et al. 2011).