This in turn may lead to a need for increasing doses of the drug to get the original desired pharmacological or therapeutic effect.

[1] Barbiturate use can lead to both addiction and physical dependence, and as such they have a high potential for excess or non-medical use,[2] however, it does not affect all users.

The chronic use of barbiturates leads to moderate degradation of the personality with narrowing of interests, passivity and loss of volition.

The somatic signs include hypomimia, problems articulating, weakening of reflexes, and ataxia.

[2] The mechanism by which barbiturate tolerance develops is believed to be different from that of ethanol or benzodiazepines, even though these drugs have been shown to exhibit cross-tolerance with each other[5] and poly drug administration of barbiturates and alcohol used to be common.