Don't lecture — open a door. Talmidim brace for mussar and shut down the moment they sense it coming. Instead, name the matter plainly and calmly, as a normal nisayon of this dor that nearly everyone faces. When you speak about it without shock or shame, you tell them it's safe to be honest, and that is more than half the work.
Wherever you can, take it one-on-one. A quiet word in the hallway reaches a boy in a way a speech to the whole shiur never will. Ask, then listen far more than you speak. Let him know that wanting help is not a weakness but a sign of strength — that the bochurim he respects most are often the ones who quietly chose to get it.
Timing matters as much as words. Catch him in a calm moment, not in the heat of a consequence, and keep your own face soft — boys read our reactions long before they hear our points. If he opens up, resist the urge to fix everything at once; a single honest exchange that ends warmly will earn you the next ten. And if he isn't ready, leave the door open rather than forcing it. You are planting, not harvesting.
Then give the conversation somewhere to land. End with a concrete, dignified next step rather than guilt — a filter he can opt into privately, installed for him, no interrogation attached. When a talk closes with a real action, the talmid walks away with hope instead of heaviness. That is the difference between a moment that passes and one that changes him.