The authors studied 15 men who committed matricide. The majority were
diagnosed as having chronic schizophrenia and had been living alone with
their mothers. Other diagnoses included substance-induced psychosis and
impulse disorders. Specific psychodynamic and environmental factors can be
identified for each diagnostic category. The authors conclude that the
matricidal impulse evolves through successive stages of psychological
development; therefore, the motives for matricide are varied and correlate
with the level of psychological development or regression.