Write about a mental illness in your world and how people respond to this.
Has the world lost it's sparkle? Does life no longer give you the interest it once did? Are your friends finding you a dull old toad? You, my friend, are suffering from Ennui. Don't let this debilitating condition drag you down. Take "Pitkin's Powders" a miraculous curative and preventative that will maintain your mind and character, restoring any damage done! One a day for prevention, two a day for cure - a snip at only a duke a dozen.A growing sense of boredom and world weariness is one of the major mental health issues that beset the empire in it's decadent phase. Politicians, ministers, emperors even fell under its dread shadow, loosing interest in their families, rivalries and business interests. If they'd caught religion, or philosophy well, these things happen but they do at least give one an interest even if it is incoherent to ones familiy, friends and colleagues. Ennui just saps the character leaving an inert shell without motivation.
Opinions on the cause remain divided. Some say that the cosmopolitan lifestyle of the later empire was fundamentally unsatisfying to the human condition and that this created a vacuum in the spirit which gradually sucked out the soul. Others laid the blame on diet with refined Sweetroot being a particular suspect following the increased consumption of this is the main cities of the empire as The Vale of Arabour's exports of marmalade surged.
In the early stages there is inertia - one wakes up feeling rested but has no inclination to rise and be about ones business. When at it one questions the point of it. As the condition progresses an ever increasing number of increasingly important things cease to be felt to be worth doing, culminating in a disinclination to eat or drink even when suffering from starvation and with food to hand.
Advertisements such as the one above not withstanding, there is no evidence for any effective drug treatments for the condition. Noting that those with active lifestyles are less prone, some believe that strenuous exercise is efficacious; and they may be right. But getting someone with a serious case of ennui on their feet and keeping them moving for several hours is no mean feat. The great thinker and empiricist Hieron Nollerute suspecting some of the early symptoms in himself took to walking 5 leagues a day and encouraged others to likewise as a prophylactic.
Mild cases can stabilise but this is rare and the sufferer gradually becomes more and more withdrawn. In the most advanced cases the sufferer falls victim to diseases typical of malnutrition and may even starve to death. Good care and nursing help put this off but this relies on wealth and/or an uncommonly supportive family or friends. Where cases have been cured or gone into remission there is a significant chance of repeat episodes.