Which of the following is NOT a common effect of certain substances?

The correct answer is that increased respiration is not a common effect of certain substances. Many substances, particularly depressants like alcohol or opioids, tend to slow down the body’s systems, which can lead to a decrease in respiration rates. On the other hand, stimulants (like cocaine or amphetamines) can cause increased heart and breathing rates.

In this context, panic, slowed reaction time, and euphoria are frequently associated with substance use. Panic can result from the psychological effects of drugs, particularly stimulants or hallucinogens. Slowed reaction time is a common effect of depressants, while euphoria is often experienced during the initial phases of substance use, due to the release of dopamine and other neurotransmitters in the brain. So, understanding that increased respiration is less consistent across different substances helps to identify it as the answer that stands apart from the others listed.