"Feelings of euphoria supplant all worries
and awareness of bodily needs. When the neural receptors in
the endogenous opiate system are artificially stimulated, the
brain loses its subtle balance. The brain pushes back so that
the rush of pleasure recedes and is replaced by strong negative
emotional states (Radke et al., 2011). Those negative emotions motivate people to seek, once again, the initial rush of pleasure"