The effects of psychoactive substances are more detrimental to adolescents and young adults who are yet going through biological, psychological, social and emotional maturation. Substance abuse is a growing pervasive global public health concern. It is a disease that is currently threatening the human existence. This paper discussed some prevalence rates of substance abuse among adolescents and young adults across many nations. It highlighted on some of the effects especially those of mental disorders. The paper elaborated more on the role of psychologists in fighting against the consequences of substance abuse. Four prominent points were discussed in this regard(a) psychologists having a better understanding of the disease (b) personal commitment in fighting the menace (c) accessing collaborative efforts among psychologists and all stakeholders and (d) offering the most appropriate therapeutic intervention at the right time. The paper offered some practical and valid recommendations calling on: national Governments and Insurance companies to offer financial support for the treatment of this class of people who are the future leaders; parents with children who abuse substances to seek early intervention and most importantly, psychologists to develop an unrelenting spirit of offering psychological treatment to young people who precious lives are rapidly claimed and destroyed by the consumption of psychoactive substances. The paper concluded that young people are valuable resources of every nation and therefore need special concern that will ensure their integral development. It is only in this way can they contribute and advance the values, social and economic development of nations.