Late-diagnosed autism is increasing, especially among women.

Research shows a sharp rise in adult autism diagnoses, with many women receiving first diagnoses in middle age; a 2024 JAMA analysis reported a 450 percent increase for adults aged 26–34 from 2011 to 2022.

Many adults are receiving first-time autism diagnoses later in life, and this trend is especially noticeable among women. Recent research documents a marked rise in adult diagnoses, including a 2024 JAMA analysis that found a 450 percent increase among people aged 26 to 34 between 2011 and 2022. The SPARK for Autism study and other sources report that roughly half of autistic adults were not diagnosed until after age 17. Clinicians and advocates point to factors such as masking, co-occurring ADHD, pandemic-era life changes, and long-standing gender and racial biases as contributors to later recognition. Key points: - A 2024 JAMA analysis reported a 450 percent increase in new autism diagnoses among adults aged 26–34 from 2011 to 2022. - The SPARK for Autism study and related research indicate about half of autistic adults were not diagnosed until after age 17. - Many adults first receive an ADHD diagnosis; Psychology Today estimates 50–70 percent of autistic people also meet criteria for ADHD. - Late diagnosis is reported as more common in females and in people with higher IQs, and masking is frequently cited as a reason symptoms were missed earlier. - Studies show racial disparities in timing of diagnosis, with an average three-to-five year delay for Black children compared with white children. Summary: The rise in late diagnoses is changing how many adults interpret long-standing challenges and highlights gaps in services that historically focused on children; many who are diagnosed later did not have access to youth-focused supports. Undetermined at this time.