The incidence of mental illness is the maximum if the causal factors affect a paicular period -

The incidence of mental illness is the maximum if the causal factors affect a paicular period of first five years of life crucial points in the life cycle of human being which are impoant from the view of mental health are prenatal period, first five years of life, school child , adolescence, old age. ref ;(page no;832)23rd edition of PARK&;s textbook of Preventive and Social medicine