I wrote a couple of posts ago on order and disorder, and while most of it I'd say was coherent enough, I think the description of decadence was, in being tempted by intellectual symmetry, pretty facile - what was written being: "totalitarianism (is) a manifestation of the the drive towards order at the expense of freedom, while decadence freedom, or rather a mistaken sense of freedom, at the expense of a wise order."
The overall idea was of two drives: one towards order and enclosure within structure, and the other towards freedom. The two forces in nature perfectly balance each other, but yet the urge towards freedom is the superior one. You could say structure exists to facilitate freedom, not vice versa; and it is the pull towards freedom that ensures the upwards evolutionary development of structure - with organisms becoming more complex, refined and internally intelligent; and developing so precisely as manifestations of this drive towards realising a conscious freedom.
But back to decadence, where I more or less wrote that totalitarianism was a symptom of the urge towards absolute order, while decadence was a symptom of the excessive pull towards freedom. I think on the human level the movement towards freedom, if done coherently and wisely, looks after of itself the issue of structure and order. Basically: "Seek ye the kingdom and all else will follow." The issue of the personality and how to live is shaped as a by-product of immersion in, or surrender to, the greater whole, the boundless freedom into which one surrenders oneself absolutely.
Decadence rather than a strong but unwise urge towards freedom is something else. It is not too inaccurate to say that it occurs where an excess of existence within a stagnating and stultifying order leads to an atrophied sense of self, and where the urge towards freedom - which can never in a living being be wholly absent - is very weak, and what is there of it satisfies itself in wallowing in various forms of sensuality- and in themselves a form of this pull downwards into order. The urge towards freedom is just strong enough to rouse one to the expelling of some energy in return for very immediate gains, but it is all very much still life within very limited and recurrent patterns and order; perhaps even the most rigid of such patterns - patterns repeating themselves to the point of addictions. I don't think it bears any real resemblance to the notion of an excess of freedom, or freedom at the expense of order; rather that which fills the space of the movement towards freedom.