Autism Diagnoses in Girls Lag Years Behind Boys, Study Finds

A major Swedish study has revealed that autism diagnoses in boys and girls follow very different timelines. The boys are most often identified between ages 10 and 14, while girls tend to receive diagnoses much later, peaking at 15 to 19. These findings challenge long-held assumptions about gender differences in autism prevalence and point to deep flaws in how the condition is detected.

For decades, autism was believed to affect boys four times as often as girls. But the new research suggests this gap shrinks dramatically with age. By 20, the male-to-female ratio drops to just 1.2, meaning diagnoses in girls effectively 'catch up' through adolescence.

The delay in identifying autistic girls has serious consequences. Many experience years of undiagnosed struggles, leading to heightened anxiety, social trauma, and lasting self-doubt. Unlike boys, girls often mask their traits by adopting socially acceptable behaviours or interests, making their autism harder to spot.

Current diagnostic tools were built around a male prototype, systematically overlooking girls who present differently. The DSM-5 attempted to address this by merging separate autism subtypes into one broad category, emphasising social communication and repetitive behaviours more inclusively. Later updates, like the DSM-5-TR, added further refinements to capture subtler traits common in girls. Yet the study's authors argue that even these changes are not enough.

Early identification transforms a child's environment and support system, helping them thrive. The findings now demand a systemic overhaul—from revised screening methods to a deeper understanding of how autism manifests across genders.

The study exposes a critical flaw in autism diagnosis: the gap between boys and girls stems not from biology but from outdated identification practices. With diagnoses nearly equal by adulthood, the pressure grows to reform tools and training. Without change, countless girls will continue facing unnecessary struggles before receiving the support they need.