Secondly, FHP/PDEP children may be less sensitive to sweet tastes and thus require higher concentrations of sucrose than do other children to achieve the same level of perceived sweetness. Although the present study did not measure sucrose sensitivity, studies on adults reveal that depressed individuals have higher detection thresholds for sucrose [54] and rate varying sucrose concentrations as less intense but more pleasant [55] compared with non-depressed adults. Human taste thresholds for sucrose (and for quinine, a bitter taste) can be lowered by enhancing systemic levels of serotonin and noradrenaline [56]. Although controversial, impaired serotonin functioning may play a causal role in the pathophysiology of depression (see [57] for review) and is evident in FHP adults [58].
