sentences:  Generally, a comedown ("down", "low", sometimes "crash") can happen to anyone as a transient symptom, but in people who are dependent on the drug (especially those addicted to it), it is an early symptom of withdrawal and thus can be followed by others.Various drug classes, most especially stimulants and to a lesser degree opioids and sedatives, are subject to comedowns.A milder analogous mood cycle can happen even with blood sugar levels (thus sugar highs and sugar lows), which is especially relevant to people with diabetes mellitus and to parents and teachers managing children's behavior, as well as in adults with ADHD.