1. The major aims are to assess: (1) the relationship of basal and alcohol-induced neurosteroid and GABA levels to the degree of acute alcohol intoxication in healthy male and female volunteers; and (2) the effect of acute pregnenolone administration on the degree of acute alcohol intoxication in these same volunteers. Specific hypotheses are:

• Baseline serum levels of pregnenolone, pregnenolone sulfate (PS), dehydroepiandrosterone (DHEA) and DHEA sulfate (DHEA-S) will be inversely correlated with the magnitude of acute behavioral responses to alcohol (sedation, anxiolysis, amnesia, psychomotor impairment and intoxication). That is, higher baseline levels of these neurosteroids will be associated with lessened behavioral responses to alcohol.
• Baseline serum levels of allopregnanolone, tetrahydrodeoxycorticosterone (THDOC), androstanediol, androsterone and GABA will be directly correlated with the magnitude of acute behavioral responses to alcohol. That is, higher baseline levels of these substances will be associated with heightened behavioral responses to alcohol.
• Acute alcohol ingestion, compared to placebo ingestion, will increase serum levels of allopregnanolone and THDOC and plasma levels of GABA and will decrease plasma levels of PS. (Effects on levels of other neurosteroids are not specifically predicted based on animal data but will be examined in an exploratory manner.)
• Acute alcohol-induced increases in serum levels of allopregnanolone and THDOC and in plasma levels of GABA will be directly correlated with the magnitude of acute behavioral responses to alcohol. Acute alcohol-induced decreases in serum levels of PS will be directly correlated with the magnitude of acute behavioral responses to alcohol. Correlations between alcohol-induced changes in other neurosteroids and changes in behavior are not specifically predicted but will be examined in an exploratory manner.
• Pregnenolone, compared to placebo, pre-treatment will antagonize the acute effects of alcohol on the behavioral measures.