Psychopharmacology: is the discipline that attempts to systematically study the effects of drugs on behaviour, cognitive functioning, and emotions. Psychoactive drugs: drugs that alter behaviour, cognitive functioning, or emotions. Effects of a drug depends on many factors. Individual"s set (psychological makeup of person) + setting. The way the drug changes activities in the cns. In general, it is a chemical that affects 1 or more biological processes . Salt, water, minerals, proteins, vitamins, carbs can all affect biological processes: when isolated, in certain amounts, can be drugs. Endogeneous substances: chemicals originating or produces within an organism that are used to carry out the normal biological functions in the body not thought of as drugs. A drug is a nonfood chemical that alters 1 or more normal biological processes in living. Pharmacodynamics: refers to the biochemical and physiological effects of drugs and their.