substance 為何變成毒品的意思？

Primary care: 就是指美國一般的家庭醫生 (general doctor)，非專科醫生 (specialist)。

Pernicious: 有害的,有毒的;惡性的,致命的,邪惡的 causing insidious harm or ruin; ruinous; injurious; hurtful; deadly; fatal, Obsolete. evil. e.g. a pernicious disease, pernicious peer pressures

escalate: 使逐步上升(增強或擴大);使(戰爭)逐步升級 to increase in intensity, magnitude, etc. e.g. to escalate a war; a time when prices escalate.

substance:
物質, 實質;本質;實體;本體, that of which a thing consists; physical matter or material, e.g. Ice and snow are different forms of the same substance, water.
本旨,主旨;要義;真義 the subject matter of thought, discourse, study, e.g. The substance of his speech was that he was better than the other candidates.
財產,財物 possessions, means, or wealth, e.g. Later he became a man of substance.

以上都是我記得曾讀過的意思，但為何文章中出現的substance，卻被解釋為毒品呢？
Job stress is far and away the leading source of stress for adults but stress levels have also escalated in children, teenagers, college students and the elderly for other reasons, including: increased crime, violence and other threats to personal safety; pernicious peer pressures that lead to substance abuse and other unhealthy life style habits; social isolation and loneliness; the erosion of family and religious values and ties; the loss of other strong sources of social support that are powerful stress busters.

erosion: 侵蝕;腐蝕 the process by which the surface of the earth is worn away by the action of water, glaciers, winds, waves, etc. e.g. Soil erosion by rain and wind is a serious problem here.

buster: (n) 破壞者;有巨大破壞力的東西, a person who breaks up something, e.g. crime busters. something that is very big or unusual for its kind.

bust up: (verb phrase)
to break up; separate, e.g. Sam and his wife busted up a year ago.
to damage or destroy, e.g. Soldiers got in a fight and busted up the bar.