Is heroin a stimulant or a depressant?

Depressant: While all opioids (drugs like opiates - heroin, oxycodone, hydrocodone, Methadone etc) are depressants, in people who are dependent on them, they are also often energizing. People in withdrawal are often very tired and lethargic, and getting more opioid may make them more stimulated and awake. Long-term withdrawal from heroin is often marked with severe low energy, fatigue and depression.