Neuropsychiatric conditions such as Attention Deficit Hyperactivity Disorder (ADHD) and autism are characterized by specific deficits in cognitive functions. Thus, neuropsychological assessment is a critical part of the diagnostic process for these conditions. Inhibition is a specific function of interest during these examinations, since it is often affected in patients with ADHD and/or autism. The Five Digits Test (FDT) is a newly developed test measuring inhibition, without requirements of reading ability, and only limited requirements of language proficiency.

The aim of this study is to investigate the validity of the FDT in patients with neuropsychiatric conditions. The FDT will be validated using the following research questions:

1. Is the FDT equivalent to the standard neuropsychological test of inhibition, the Color-Word Interference Test from the Delis-Kaplan Executive Function System in patients with neuropsychiatric conditions? (Convergent validity)
2. Is the FDT consistent with self-assessment of inhibition and behavioral regulation in every day life using the Behavior Rating Inventory of Executive Function - Adult Version (BRIEF-A)? (Ecological validity)
3. Are there differences in validity in the first two research questions due to language background or due to reading and writing difficulties?
4. Are there differences between patients with neuropsychiatric conditions and healthy controls in the performance of the FDT?

In a cross-sectional design, patients with or under examination for either ADHD or autism will be invited to participate in the project. Patients will receive both written and oral information about the project and sign informed consent before data collection begins. After this, patients will complete the BRIEF-A and answer some questions regarding demographic and health related factors. Before starting the testing session patients will be randomly assigned to perform FDT first or the CWIT first, to control for test-retest or learning effects. Healthy controls will be recruited through advertisements, otherwise the data collection procedure will be the same as for patients.

The validity of FDT will be validated against the CWIT and the BRIEF-A using Pearson and/or Spearman correlation coefficients. The strength of the correlations will be interpreted using Cohen's (1992) cutoffs of weak (0.1), medium (0.3) and strong (0.5) correlations. Additionally, multiple linear regressions will be performed to investigate and adjust for background variables. Student's t-tests and/or ANCOVAS will be used to compare differences between groups.

Inclusion Criteria:

• age 18 and above
• Diagnosed with a ADHD or Autism, alternatively under examination these diagnoses

Exclusion Criteria:

• Addiction of alcohol or other substances
• Not speaker of Swedish to such extent that cannot read or comprehend the informed consent forms
• On sedatives, such as sleep or pain medication
• Not being able to participate in a neuropsychological examination, or to give informed consent

All patients referred to neuropsychiatric examination, ADHD and/or autism at the Psychiatric Clinic at Umeå University Hospital will be offered to participate in the study. A comparison group of healthy volunteers will be recruited using advertising.

National regulations about sharing data regarding patients.