psychological dependence relate to emotional and motivational impairment, physical dependence entails somatic symptoms e.g. increased heart rate, sweating, tremor. The type of dependence experienced after chronic use varies between different substances (see table 1). Although psychological dependence and physical dependence are distinct entities, they should not be characterized as mutually exclusive. Empirical studies have shown that cravings, which are traditionally associated with psychological dependence, involve a physiological element. See also Substance dependence Substance use disorder References Substance dependence Psychopathological syndromes