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        <r:String xml:lang="sv">CATSS24 - The Child and Adolescent Twin Study in Sweden (24 år)</r:String>
        <r:String xml:lang="en">CATSS24 - The Child and Adolescent Twin Study in Sweden (24 years)</r:String>
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          <r:String xml:lang="en">Karolinska Institutet</r:String>
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      <r:Content xml:lang="sv">CATSS översikt:

Tvillingstudien CATSS är en pågående longitudinell tvillingstudie som riktar sig till alla tvillingar födda i Sverige sedan 1 juli 1992. Sedan 2004 intervjuas tvillingföräldrar om barnens somatiska och psykiska hälsa och sociala miljö i samband med deras 9-årsdag (CATSS9). Vid 15 (CATSS15) och 18 (CATSS18) års ålder, fyller tvillingar och föräldrar i en webenkät som, förutom bedömningar av somatisk och mental hälsa, inkluderar mått på personlighetsutveckling och psykosocial anpassning. Vid 24 års ålder (CATSS24) fyller endast tvillingar i en webenkät som främst fokuserar på mental hälsa.

CATSS24:

CATSS24 startade 2016. Studien inkluderar alla 24-åriga tvillingar i Sverige, oavsett om de deltagit i tidigare CATSS-studier eller inte.  Urvalet består av enäggstvillingar samt tvåäggstvillingar av samma eller olika kön inom tvillingparet. Det totala antalet deltagande tvillingar i CATSS24 är för närvarande ca 11 600 av 21 900 inbjudna (december 2025). Svarsfrekvensen ligger på 53%.  I samband med CATSS24 får de som inte redan lämnat DNA via salivprov ett nytt erbjudande. Salivprovet används för zygositetsbestämning och genotypning. Antalet genotypade tvillingar i CATSS24 är för närvarande 7 300 (december 2025).

De frågeområden som ingår i CATSS24-enkäten finns listade nedan. Detaljerad information om variabler finns på strdata.se.

AUDIT - Alcohol Use Disorders Identification Test
CES-D - Center for Epidemiologic Studies Depression Scale;
DUDIT - Drug Use Disorders Identification Test;  ​
DCQ - Dysmorphic Concerns Questionnaire
HADS - Hospital Anxiety and Depression Scale​;
HRS-I - Hoarding Rating Scale-Interview
LHA - Life History of Aggression
OCI-R - Obsessive-Compulsive Inventory-Revised
PLE - Psychotic-like Experiences
EDI-2 - Eating Disorder Inventory-2
Tvillingskap
Premenstruella besvär
Självmordstankar/försök
Astma och allergier
FFQ2020 - Food Frequency Questionnaire (uppdaterad version)</r:Content>
      <r:Content xml:lang="en">CATSS overview:

The Child and Adolescent Twin Study in Sweden (CATSS) is an ongoing longitudinal twin study targeting all twins born in Sweden since July 1, 1992. Since 2004, parents of twins are interviewed regarding the children's somatic and mental health and social environment in connection with their 9th birthday (CATSS9). At age 15 (CATSS15) and 18 (CATSS18), twins and parents complete questionnaires that, in addition to assessments of somatic and mental health, include measures of personality development and psychosocial adaptation. At the age of 24 (CATSS24) only twins participate in a web survey that mainly focuses on mental health.

CATSS24:

CATSS24 started in 2016. The study includes all 24-year-old twins, regardless of whether they participated in earlier CATSS-studies or not. The sample consists of both identical (monozygotic) and fraternal (dizygotic) twins, including same-sex and opposite-sex pairs. The total number of twins participating in CATSS24 is currently 11,600 out of 21,900 invited (December 2025). The response rate is 53%. Participants who have not already provided a DNA sample via saliva are requested to do so again. The saliva sample is used for zygosity determination and genotyping. The number of genotyped twins in CATSS24 is currently 7,300  (December 2025). 

The question areas in the CATSS24 survey are listed below. For detailed information about variables, visit strdata.se.

AUDIT - Alcohol Use Disorders Identification Test
CES-D - Center for Epidemiologic Studies Depression Scale
DUDIT - Drug Use Disorders Identification Test
DCQ - Dysmorphic Concerns Questionnaire
HADS - Hospital Anxiety and Depression Scale​
HRS-I - Hoarding Rating Scale-Interview
LHA - Life History of Aggression
OCI-R - Obsessive-Compulsive Inventory-Revised
PLE - Psychotic-like Experiences
EDI-2 - Eating Disorder Inventory-2
Zygosity
Premenstrual syndrome
Suicidal thoughts/attempts
Asthma and allergies
FFQ2020 - Food Frequency Questionnaire (updated version)</r:Content>
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