Since anesthetics administered by inhalation became available, there have been instances of their self-administration, not to produce unconsciousness and anesthesia, but to induce a sense of giddiness, intoxication and sometimes euphoria. Among the agents used in this way are ether, chloroform and nitrous oxide. More recently, certain volatile solvents - such as the acetone found in nail varnish remover, toluene found in the glue used to make models, and petrol - have been used for this purpose. These substances are brain depressants and produce effects somewhat comparable to those produced by alcohol, although the symptoms vary from agent to agent. Initially, there may be mild euphoria and exhilaration, followed by confusion, disorientation and ataxia (disturbed gait), and the user may behave as though drunk.

Some of the substances, including petrol and toluene, may also produce symptoms rather like those sometimes induced by the hallucinogens, such as:

• - a marked euphoria
• - grandiose delusions
• - recklessness
• - other delusions and hallucinations
• - substantial loss of self-control
• - convulsions and coma

Certain of the substances, including petrol, benzene (used in solvents) and carbon tetrachloride (used in dry cleaning), are more likely to result in grave complications, such as liver or kidney damage.
Physical dependence, at least of the magnitude associated with the use of a drug of the alcohol, barbiturate or opium type, does not ordinarily occur. However, abrupt withdrawal after the person has been using substantial amounts may be associated with some degree of lethargy, depression and irritability .
In summary, a number of volatile solvents will produce psychological dependence of varying degrees because of a liking for the effects they produce. Some of these substances will also produce tolerance. The question of physical dependence remains open, but if it occurs, the syndrome is usually less intense than that associated with drugs such as alcohol, barbiturates and opiates.