When diagnosing children, it can be very difficult due to their brains still developing. What are proper diagnoses that can be explored for a first grader with impulsive aggressive actions against other children with the following symptoms?

• The client's aggression is unpredictable in school. Generally he gets along with his classmates, he is not disruptive, and is often the first to finish his work.
• During playtime in school, he likes to play alone.
• During playtime he ignores and tunes out other children. Client lashes out and hits children if they continue to pursue him during playtime when he want to be alone.
• He is at risk of being expelled.

At what stage is too early for a proper diagnosis?