Madness is a stock theme in Ballard's work, appearing in virtually all of his non-science fiction work.  Thematically, the novels listed here range from pathological sexual obsession ("Crash") to one man’s desire to escape the civilised world and challenge himself, and his sanity, to a battle against nature ("Concrete Island"). Notions of hysteria and collective, infectious madness have been long-term interests of Ballard's, and are demonstrated most clearly in "High Rise", a cautionary tale about the psychological dangers of physical and mental isolation and the pressures of capitalism.  His most recent four novels – "Cocaine Nights", "Super-Cannes", "Millennium People" and "Kingdom Come" explore the impact upon psychological health of modern phenomena such as expansive shopping malls, gated communities and the paradoxical pressures of excessive leisure.