People with ADHD and dependency rarely respond as they should to ADHD drugs. A randomised study from Karolinska Institutet in Sweden now shows that it is possible to obtain the desired efficacy by administering the drug in higher doses. The results of the study are published in the scientific journal Addiction.
ADHD is much more common in people who use drugs than in the population at large. ADHD can be treated with methylphenidate, a CNS stimulant used for both children and adults. However, no previous studies have been able to show that methylphenidate is effective against ADHD in people with dependency. One possible reason for this lack of potency is that the doses tested were too low to have an effect on people with ADHD and long-standing dependency, since such people have often developed a tolerance to CNS stimulants.
In this latest study, researchers examined the effect of the drug on prison inmates with ADHD and an amphetamine dependency, using doses up to double those administered in previous studies on people with dependency. What they found was that the experimental group had fewer relapses into drug use, displayed fewer ADHD symptoms and adhered to their treatment regimens for longer than the placebo group.
"We've shown for the first time that ADHD in these people is treatable," says lead-author Dr Maija Konstenius at the Department of Clinical Neuroscience. "Moreover, the treatment led to fewer relapses in drug use, which is a very significant finding since a return to crime is often linked to drug abuse in this group."
The present study was a randomised placebo-controlled study involving 54 incarcerated men diagnosed with ADHD and with amphetamine dependencies. The participants were randomly assigned to either of two groups, one that received methylphenidate (Concerta) and one that received a placebo (sugar pill) for a total of 24 weeks. The participants began their treatment two weeks before their release and then continued it during non-custodial care. They also received psychological therapy to help them handle the risk of relapsing into drug use.
The study was conducted in partnership with the Stockholm County Council and the Swedish Prison and Probation Service and was financed by grants from the Swedish Research Council and other bodies.