No, an employer may accept a negative/dilute test result as a negative test. If the employer wants a retest it may do so, however, it must be stated in the employer's policy and the employer must require a retest of all individuals that have a negative/dilute result in the same testing category.
Alcohol affects activity of such neurotransmitters as glutamate, GABA, and dopamine; caffeine blocks the action of the neurotransmitter adenosine. Such changes are studied in the field of psychopharamacology, which concerns the effects of drugs on the mind and brain. This field investigates both recreational drugs such as alcohol, caffeine, marijuana, cocaine, and LSD, and therapeutic drugs such as antidepressants and antipsychotics.
Hallucinogens and Dissociative Drugs. Laboratory studies suggest that dissociative drugs, including PCP, ketamine, and DXM, cause their effects by disrupting the actions of the brain chemical glutamate at certain types of receptorsâcalled N-methyl-D-aspartate (NMDA) receptorsâon nerve cells throughout the brain (Morgan, 2012; Morris, 2005).