A definite diagnosis of dependence should usually be made only if three or more of the following have been experienced or exhibited at some time during the previous year:

(a) a strong desire or sense of compulsion to take sedatives or hypnotics;

(b) difficulties in controlling sedative or hypnotic-taking behaviour in terms of its onset, termination, or levels of use;

(c) a physiological withdrawal state when sedative or hypnotic use has ceased or been reduced, as evidenced by: the characteristic withdrawal syndrome for sedatives or hypnotics; or use of the same (or a closely related) substance with the intention of relieving or avoiding withdrawal symptoms;

(d) evidence of tolerance, such that increased doses of sedatives or hypnotics are required in order to achieve effects originally produced by lower doses;

(e) progressive neglect of alternative pleasures or interests because of sedative or hypnotic use, increased amount of time necessary to obtain or take the substance or to recover from its effects;

(f) persisting with sedative or hypnotic use despite clear evidence of overtly harmful consequences, such as depressive mood states consequent to periods of heavy substance use, or drug-related impairment of cognitive functioning; efforts should be made to determine that the user was actually, or could be expected to be, aware of the nature and extent of the harm.

Narrowing of the personal repertoire of patterns of sedative or hypnotic use has also been described as a characteristic feature.

It is an essential characteristic of the dependence syndrome that either sedative or hypnotic taking or a desire to take sedatives or hypnotics should be present; the subjective awareness of compulsion to use drugs is most commonly seen during attempts to stop or control substance use.