Abulia means absence of will-power or wish-power. This term implies that the individual has a desire to do something but the desire is without power or energy. Abulia itself is rare and with a few exceptions occurs only in the schizophrenias. The more frequent disturbance in the will is a reduction or impairment (hypobulia) rather than a complete absence. Bleuler included abulia and hypobulia among the fundamental symptoms of the schizophrenias.
Anhedonia means absence of pleasure in acts that are normally pleasureable. It is seen often in schizophrenics and may be one of the earliest signs in the pseudoneurotic variety described by Hoch and Polatin.