Which of the following is a sign of substance abuse?

• A. Noticeable change of personality
• B. Consistent cheerful mood
• C. Steady attendance
• D. Excellent driving record

Answer: (A)

Behavioral changes, especially noticeable shifts in personality, can indicate substance abuse because substances can alter mood, thinking, and behavior, leading to a departure from a person’s usual demeanor. You might observe mood swings, increased irritability, secrecy, withdrawal, or neglect of responsibilities, which signal impairment that can affect safety and performance. In safety-sensitive roles, these changes are a concern because they can undermine judgment and reaction time. By contrast, a consistently cheerful mood, steady attendance, and an excellent driving record tend to reflect reliability and normal functioning rather than signs of misuse.