Health ministry of republic of moldova the university of medicine and pharmacy nicolae testemiţanu

Altered states of consciousness caused by alcohol, stimulants, 
marijuana, hallucinogens etc. 
Consciousness may be altered in a dramatic fashion by the use of 
psychoactive drugs, which affect the interaction of neurotransmitters and 
receptors in the brain. They include illegal “street drugs,” tranquilizers 
and other prescription medications, and such familiar substances as alco-
hol, tobacco, and coffee.
The major categories of psychoactive drugs include depressants, 
which reduce activity of the central nervous system; sedatives, another 
type of depressant that includes barbiturates such as Seconal and 
Nembutal; anxiolytics (traditionally referred to as tranquilizers); 
narcotics including heroin and its derivatives which are addictive drugs 
that cause both drowsiness and euphoria, and are also pain-killers; 
psychostimulants, such as amphetamines and cocaine, which stimulate 
alertness, increase excitability and elevate moods; and psychedelics or 
hallucinogens, such as marijuana
 
and LSD. Psychedelics, which affect 
moods, thought, memory, and perception, are particularly known for 
their consciousness-altering properties. They can produce distortion of 
one’s body image, loss of identity, dreamlike fantasies, and hallucina-
tions. LSD (
lysergic acid diethylamide
), one of the most powerful psy-
chedelic drugs, can cause hallucinations in which time is distorted, 
sounds produce visual sensations, and an out-of-body feeling is experi-
enced. Various states of consciousness are viewed differently by diffe-
rent cultures and even subcultures. In the United States, for example, 
hallucinations are devalued by mainstream culture as a bizarre sign of 
insanity, whereas the youth counterculture of the 1960s viewed drug-in-
duced hallucinations as enlightening, “mind-expanding” experiences. In 
certain other societies, hallucinations are respected as an important the-
rapeutic tool used by ritual healers. 
Drugs are substances that can alter the functioning of a biological 
system. Psychoactive drugs interact with the central nervous system and 
alter mood, perception, thinking, and behavior.
Alcohol
is the most widely used psychoactive drug. It is a dep-
ressant and suppresses nerve impulses. People sometimes feel elated 
when they drink a small amount of alcohol because it slows down the 
brain centers that normally control social inhibitions. With increased 

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doses, other central nervous system functions deteriorate. Blood alcohol 
levels of 0.05 percent will relax inhibitions; 0.01 percent is usually 
defined as drunkenness, levels of 0.3 percent to 0.4 percent may cause 
coma, and levels exceeding about 0.5 percent cause death. 
Alcohol consumption has little effect on short-term and long-term 
memory, but it does affect the transfer of information from short-term to 
long-term memory. Alcoholic blackout is the loss of memory for events 
that occurred while drinking. State-dependent memory also influences 
recall, so that a person can recall incidences experienced under alcohol’s 
influence when drinking, but not when sober.