Research

A study with over 700,000 patients enables the age of onset of different mental disorders to be established

A study published in the journal Molecular Psychiatry, which is part of the Nature group, has conducted a meta-analysis with data from 192 epidemiological studies that include 708,561 patients, to determine the age at which different mental disorders usually make their debut appearance.

Paolo Fusar-Poli, Marco Solmi and Joaquim Raduà

The study is headed up by doctors Joaquim Raduà, head of the IDIBAPS research group Imaging of mood- and anxiety-related disorders, Marco Solmi, from the University of Padua, and Paolo Fusar-Poli, of King’s College London.



Prevention at age of onset of the disorder

Mental disorders are one of the main causes of disability. Various studies indicate that good prevention would enable their appearance to be reduced. “If we were capable of detecting in time any change that advises of a possible mental disorder, perhaps we could correct it and ensure that the brain matures in a healthy way, preventing the disorder from appearing”, explains Raduà.

Despite this, “to ensure that a prevention programme is effective, it needs to be conducted at the specific age of onset for each mental disorder. To date, the age of onset of the different disorders was not a well-known subject, because investigating it is more complex than it may seem”.

The team of researchers combined, for the first time, all the information on the age of onset of mental disorders from the epidemiological studies published to date. Thus, a sample of over 700,000 people from all five continents was built up. Raduà adds that “the analyses were not easy, because each disorder follows an atypical and unique pattern, therefore we had to create new algorithms for meta-analysis and the computers spent weeks, or even months, performing the calculations”.


Age of onset follows a continuum

One result of the study is that the age of onset for most mental disorders is 14 years, a time at which the brain is experiencing important maturational changes.

Furthermore, the study concludes that the majority of mental disorders appear uninterruptedly during the first 25 years of life. “We cannot divide the disorders between some that occur in childhood and others that appear in adulthood”.

This questions the current division of mental health between schemes for people aged under 18 years and schemes for those aged over 18, “because for many people, attention becomes more fragmented when they reach the majority of age. Therefore, we ask if it would not be better to adapt the mental health schemes to the different ages of onset of the different disorders. We know that age of onset is not the only factor to be taken into account, but this study puts the question on the table.”


Age of onset of the main mental disorders

Disorder

Average age of disorder onset

(50% of cases appear before this age)

25% of cases appear before the age of...

25% of cases appear after the age of...

Phobia / Separation anxiety

8 years

5 years

17 years

Autism spectrum disorder

9

5

14

Attention deficit hyperactivity disorder

12

8

18

Social anxiety

13

9

17

Anorexia nervosa

17

14

22

Bulimia nervosa

18

15

22

Obsessive-compulsive disorder

19

14

29

Binge eating disorder

20

16

25

Disorder associated with cannabis consumption

22

19

29

Schizophrenia

25

21

35

Panic disorder

26

18

36

Alcohol abuse disorder

27

19

44

Depression

30

21

44

Posttraumatic stress disorder

30

17

48

Generalised anxiety disorder

32

20

42

Bipolar disorder

33

22

49

Acute and transitory psychoses

35

27

45

Article reference

Age at onset of mental disorders worldwide: large-scale meta-analysis of 192 epidemiological studies

Marco Solmi, Joaquim Radua, Miriam Olivola, Enrico Croce, Livia Soardo, Gonzalo Salazar de Pablo, Jae Il Shin, James B. Kirkbride, Peter Jones, Jae Han Kim, Jong Yeob Kim, Andrè F. Carvalho, Mary V. Seeman, Christoph U. Correll & Paolo Fusar-Poli.  Mol Psychiatry (2021). https://doi.org/10.1038/s41380-021-01161-7