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.
Psychoactive drug use can be traced to prehistory. There is archaeological evidence of the use of psychoactive substances (mostly plants) dating back at least 10,000 years, and historical evidence of cultural use over the past 5,000 years.here are many ways in which psychoactive drugs can affect the brain. Each drug has a specific action on one or more neurotransmitter or neuroreceptor in the brain. Drugs that increase activity in particular neurotransmitter systems are called agonists.