Which of the following is a common sign of substance dependence?

Withdrawal symptoms are a hallmark sign of substance dependence. When a person has developed a physical or psychological reliance on a substance, their body adapts to its presence. If the substance is reduced or stopped, the person typically experiences a range of symptoms, which can include anxiety, irritability, nausea, tremors, and other physical manifestations. These symptoms highlight the body's dependency on the substance to function normally.

In contrast, increased social interactions, stable employment, and enhanced concentration are generally not associated with substance dependence. Increased interactions might indicate better social functioning, rather than dependence, while stable employment can suggest responsibility and absence of dependence. Enhanced concentration could be a temporary effect of some substances, but overall, it does not reflect the signs of dependency. Thus, withdrawal symptoms serve as an essential indicator of substance dependence, signaling that the individual may experience negative effects when not using the substance.