How do drugs change mood over time?

Drugs can change mood by altering brain systems involved in reward, stress, and emotional regulation. Initially, substances may produce effects such as euphoria, relaxation, or increased energy, depending on the drug. Over time, these effects often become less predictable, and mood may become more unstable.

With repeated use, individuals may experience increased irritability, anxiety, low mood, or emotional blunting, particularly between episodes of use. This reflects both brain adaptation and the absence of the substance’s effects when not using.

As patterns develop, drug use may shift from enhancing mood to managing discomfort. This can reinforce continued use, as the substance is used not only to feel better but also to avoid feeling worse.