Brekka is a planet whose entire economy depends on supplying felicium to the addicted people of neighbouring Ornara.
Brekka is the neighbour of Ornara in the star system seen in Symbiosis. Its whole economy and industry were devoted to producing felicium, which the Ornarans believed was medicine for a plague, and the Brekkans received everything else they needed from Ornara in return.
The Brekkans could not travel in space themselves and relied on Ornaran ships. When the crew learned that felicium was a narcotic and the plague long gone, Picard refused to repair the Ornaran freighters. This left Brekka facing the loss of its only market and the need to change its way of life.