ongitudinal European Autism Project (LEAP). Follow-up-2 (wave-3)

Recruitment & Eligibility

Status: Recruiting

Sex: Not specified

Target Recruitment: 288

Inclusion Criteria

Having participated in LEAP-1 and/or LEAP-2; the criteria observed at wave-1
were:

ASD group:
1. Male or female aged 6-30 years with an established clinician diagnosis of
Autism Spectrum Disorder according to DSM-5 criteria;
2. Male or female with an IQ of 50 or above;
3. Able to participate and willing to give written informed consent;
(a) Where participants are their own legal guardian (i.e. aged 18 years and
older without intellectual disabilities and demonstrated capacity to consent),
written informed consent from the volunteer;
(b) Where participants are minors and/or do not have capacity to consent,
written informed consent from the parent or legal guardian; verbal assent from
the volunteer prior to each assessment; for adolescents and adults without
capacity to consent: additional written assent from the volunteer (easy-read
version);
4. Availability of a parent or legal guardian to provide information about the
volunteer*s behaviour and symptoms by completing (on-line) questionnaires,
during the institute visit, a separate home-visit or over the telephone,
5. Availability of a parent or carer to accompany the volunteer to all
institute visits where participants are unable to travel on their own;
6. Participant on stable medication (min 8 weeks) at entrance point and over
the course of study.

Typically Developing (TD) control group:
1. Male or female aged 6-30 years;
2. Able to participate and willing to give written informed consent;
For minors <18 years: Informed written consent from the parent or legal
guardian, verbal assent from the volunteer prior to each assessment;
3. For minors <18 years: Availability of a parent who provides information
about behaviour/ symptoms during the institute visit, a separate home-visit or
over the telephone.

Intellectual disabilities (ID) control group:
1. Male or female aged 12-30 years;
2. Presence of syndromic forms of ID (Down*s Syndrome) and/or unspecified
general intellectual disabilities;
3. Availability of a parent or legal guardian to provide written informed
consent; verbal assent from the volunteer prior to each assessment;
4. Availability of parent or caregiver who accompanies the volunteer to all
institute visits and provides information about the volunteer*s behaviour and
symptoms by completing (on-line) questionnaires, and either during the
institute visit, a separate home visit, or over the telephone;
5. Participant on stable medication (minimum 8 weeks) prior to each assessment
visit.

Exclusion Criteria

All groups:
1. Presence of significant hearing or visual impairments not correctable by
glasses or hearing aids;
2. A history of alcohol and / or substance abuse or dependence in the past
year;
3. Presence of any MRI counter-indications (e.g., metal implants, braces,
claustrophobia) or failure to give informed written consent to MRI scanning (or
to provide GP details at centres where this is a pre-condition for scanning);
4. Presence or history of any Neurological Disorder/ significant trauma.

ASD group:
Presence of psychosis or bipolar disorder.

TD group:
Presence of any DSM-5 axis I and II psychiatric disorders.

Study & Design

Study Type: Observational invasive

Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
<p>Trajectory of clinical symptomatology over time and in relation to underpinning<br /><br>cognitive and neurobiological abnormalities; identification of biomarkers that<br /><br>link to symptomatology and/ or that can be used to stratify ASD samples and/or<br /><br>to diagnose ASD, and/or serve as outcome markers.<br /><br><br /><br>Primary parameters are:<br /><br>- Severity of ASD and comorbid symptoms (measured by questionnaires,<br /><br>psychiatric observation (ADOS) and psychiatric developmental interview (ADI-R)<br /><br>- Performance on neurocognitive tests<br /><br>- Brain structure and functioning, as measured by MRI and EEG/ERPs<br /><br>- Attention and social attention, as measured by eye-tracking technology<br /><br></p><br>

Secondary Outcome Measures