ADHD Medication and Predictors of Treatment Outcome

The specific aims for the ADAPT study are:

• Investigate if certain gene polymorphisms are associated with poor effect of ADHD drugs (non-responders).
• Investigate if other biologically, phenotypic or psychosocial factors are associated with poor effect of ADHD drugs (non-responders).
• Investigate if the frequency of side-effects of ADHD drugs differs between children with different genotypes.
• Investigate if the frequency of side-effects of ADHD drugs differs between children with different phenotypic and/or psychosocial factors

Method:

This study has a naturalistic design. The aim is to map all new treatments with ADHD drugs at all 13 public BUP units in Stockholm County, one BUP unit on Gotland, and three BUP units in Västerbotten Region. The participation means that medication is initiated as planned in normal clinical practice by the child´s ordinary physician, and beyond this only means a somewhat denser and more structured follow-up. In addition, the investigators will ask for saliva samples from the patient and his/her parents. The investigators aim at including at least 1000 individuals in total in the study.

Part of the data will be collected via the national Quality Register for ADHD Treatment Follow-up (BUSA), which has approved security procedures approved by the Swedish Data Inspection Board.

Case report forms are computerized and separate from the database registry for collected study data. The database and detailed variable lists are constructed in collaboration with professional database managers.

Standard Operation Procedures are designed in collaboration by project coordinator, study nurse and principal investigator, and may be revised after pilot phase.

Collected samples will be stored at KI biobank.

Data analysis:

• To judge if the patient is a responder to ADHD drugs the SNAP-IV rating of ADHD symptoms (before and after medication start) is used. The patients who at 3 months have an at least 40% reduction in SNAP-IV score are reckoned "responders" and those who at the same time point have a less than 20% change in SNAP-IV score are reckoned "non-responders". Differences between the groups will be analyzed with logistic regression, with responder status as depending variable, and genotype and the other risk markers (biological, phenotypic, and psychosocial markers) as independent variables after correction for symptoms at baseline. Even a 50% drop-out rate will (i.e. 1000 out of estimated 2000 eligible individuals) give a 98% power to identify a 49% increase in non-responder proportion for a specific genotype.
• Concomitantly, the outcome in side-effects, heart rate, blood pressure, weight (z-score) and length (z-score) will be analyzed with linear regression with the same independent variables.
• The analyses are performed separately for each ADHD drug.
• There are significantly more boys than girls (about 4:1) with ADHD. Given the sex difference in prevalence it is obvious to also include sex as a covariate in our analyses of treatment outcome.
• Missing data will be treated according to the principles of complete case and multiple imputation.

Inclusion criteria

• Clinical diagnosis of ADHD
• Starting medication against ADHD symptoms with atomoxetine, methylphenidate, lisdexamphetamine, or guanfacine

Exclusion criteria

Any medication against ADHD the last 3 months