a year later) to diagnosis (median another year later). There were other minor differences in disorders with fewer (<10) separate studies for sex or onset definition, for which we suggest caution as the estimations may be less accurate than others.Table 2Age at onset by onset definition and by sex for mental disorders (ICD-11 blocks highlighted in italics).DisorderOnset definition/sexSamples Peak age at onset (years)Proportion onset by 14 yearsProportion onset by 18 yearsProportion onset by 25 yearsp25Medianp75Any mental disorderFirst symptoms54.541.5%50.0%69.5%81827Any mental disorderFirst diagnosis65.538.6%54.1%68.3%91633Neurodevelopmental disordersFirst symptoms85.540.4%56.0%62.9%716–Neurodevelopmental disordersFirst diagnosis115.561.3%82.6%95.0%71216Neurodevelopmental disordersFemale59.559.6%74.5%82.2%71218Neurodevelopmental disordersMale49.567.0%81.2%89.0%71115Autism spectrum disorderFirst diagnosis25.572.4%89.8%94.8%5914Autism spectrum disorderFemale25.580.1%92.3%96.0%5812Autism spectrum disorderMale25.580.6%92.4%96.0%5812Attention deficit hyperactivity disorderFirst symptoms24.599.8%99.8%100.0%457Attention deficit hyperactivity disorderFirst diagnosis99.556.2%72.5%91.8%81218Attention deficit hyperactivity disorderFemale39.565.0%81.0%95.2%81116Attention deficit hyperactivity disorderMale39.567.5%81.3%94.9%81115Anxiety and fear-related disordersFirst symptoms314.545.1%59.9%71.9%51527Anxiety and fear-related disordersFirst diagnosis185.535.5%48.5%71.0%91826Anxiety and fear-related disordersFemale619.511.6%22.9%45.8%182640Anxiety and fear-related disordersMale719.521.8%31.4%52.4%152437Specific phobia/separation anxiety disorderFirst symptoms124.571.2%77.6%82.8%5716Specific phobia/separation anxiety disorderFirst diagnosis95.572.1%76.0%85.0%6916Specific phobia/separation anxiety disorderFemale24.558.3%60.6%68.2%5830Specific phobia/separation anxiety disorderMale25.550.0%53.6%70.2%71326Social anxiety disorderFirst symptoms914.554.6%75.4%81.5%71317Social anxiety disorderFirst diagnosis714.547.5%77.1%85.4%101417Panic disorderFirst symptoms1015.511.9%28.9%56.4%172232Panic disorderFirst diagnosis1039.59.3%20.7%43.8%192740Panic disorderFemale320.520.8%29.0%53.4%162431Panic disorderMale315.516.1%32.9%56.9%162231Generalised anxiety disorderFirst symptoms1315.59.4%21.3%32.8%193952Generalised anxiety disorderFirst diagnosis845.57.5%15.2%27.3%233448Obsessive-compulsive related disorderFirst symptoms614.523.4%48.1%71.6%141825Obsessive-compulsive related disorderFirst diagnosis1114.524.1%44.1%56.4%142035Obsessive-compulsive related disorderFemale415.516.9%32.8%55.5%162330Obsessive-compulsive related disorderMale410.527.7%42.6%67.1%132027Feeding or eating disordersFirst symptoms415.510.2%40.1%77.2%161924Feeding or eating disordersFirst diagnosis715.516.0%44.7%74.2%151825Feeding or eating disordersFemale414.523.0%54.8%76.5%141723Feeding or eating disordersMale414.537.6%67.3%86.9%121519Anorexia nervosaFirst symptoms315.520.4%59.9%89.0%141620Anorexia nervosaFirst diagnosis515.510.6%37.3%54.6%162287Binge eating disorderFirst symptoms219.515.5%31.4%70.4%162028Binge eating disorderFirst diagnosis315.58.2%34.5%73.5%162025Trauma-related disordersFirst symptoms625.513.3%23.4%33.0%183348Trauma-related disordersFirst diagnosis715.519.4%31.3%46.1%152946Disorders due to substance use or addictive behavioursFirst symptoms3415.58.2%39.1%78.4%161923Disorders
