How they harm the body
Higher doses can cause impairment of memory, judgment and coordination, irritability, paranoia,3 and suicidal thoughts. Some people experience the opposite of the intended effect, such as agitation or aggression.
An example is Zyprexa
Classic hallucinogens are thought to produce their perception-altering effects by acting on neural circuits in the brain that use the neurotransmitter serotonin (Passie, 2008; Nichols, 2004; Schindler, 2012; Lee, 2012). Specifically, some of their most prominent effects occur in the prefrontal cortex—an area involved in mood, cognition, and perception—as well as other regions important in regulating arousal and physiological responses to stress and panic.
An example is LSD.
Inhalant use can cause damage to the heart, kidneys, brain, liver, bone marrow and other organs. Inhalantsstarve the body of oxygen and force the heart to beat irregularly and more rapidly. Users can experience nausea and nosebleeds and lose their sense of hearing or smell.
An example is Glue.