Justin Bieber -- His People Say Psychotherapy is Best Hope

Justin Bieber's people are asking the singer to come back to L.A. so they can sit with him and convince him to go into therapy ... IMMEDIATELY.

Sources connected with Bieber tell us ... they have been trying to get him into rehab for months, but he has scoffed at the idea -- he won't have a conversation about it and insists he doesn't need it.

So we're told his people believe the next best step is psychotherapy ... to deal with both his drug problem and the underlying issues that have caused it. We're told Justin has not rejected the notion of therapy and is willing to have the discussion when he returns to L.A.

Justin's team have played armchair shrink over the last year, and they believe the root problems involve his upbringing as well as the obvious -- being a child star who grew up rich and famous and got a little too used to it.