Outcome and prognostic factors in infantile autism and similar conditions: a population-based study of 46 cases followed through puberty.

Doctors tracked 46 kids with autism from childhood through puberty. They wanted to know which early signs best predict teen outcomes.

They checked IQ scores and looked for any words the kids used before age six.

Two things stood out: the child's IQ at diagnosis and early talking. These two clues told the story later on.

Kids who talked early and had higher IQs did better as teens.

Billstedt et al. (2005) followed the same idea for 13–22 years. They also saw that childhood IQ and early phrase speech shaped adult life. Only four of their 120 adults lived alone.

Antaki et al. (2008) looked at a younger group at age 24. Half still had poor outcomes, but again early IQ and autism severity scores forecast the result.

Busch et al. (2010) show why the IQ link matters in therapy. Their parent-led program helped preschoolers gain language only when baseline IQ was 50 or above. The 1987 warning signs guide who gets the most from early intervention.

When you assess a preschooler, note IQ and any spoken words. Share these facts with families. They set real hopes and steer you toward intense language goals for kids below those cut-points. Use the data to argue for extra hours or alternative methods when early IQ or speech is low.