Long-term efficacy of ADHD pharmacotherapy in children

Effect of treatment modality on long-term outcomes in attention-deficit/hyperactivity disorder: a systematic review

Background

Evaluation of treatments for attention-deficit/hyperactivity disorder (ADHD) previously focused on symptom control, but attention has shifted to functional outcomes. The effect of different ADHD treatment periods and modalities (pharmacological, non-pharmacological, and combination) on long-term outcomes needs to be more comprehensively understood.

Methods

A systematic search of 12 literature databases using Cochrane’s guidelines yielded 403 English-language peer-reviewed, primary studies reporting long-term outcomes (≥2 years). We evaluated relative effects of treatment modalities and durations and effect sizes of outcomes reported as statistically significantly improved with treatment.

Results

The highest proportion of improved outcomes was reported with combination treatment (83% of outcomes). Among significantly improved outcomes, the largest effect sizes were found for combination treatment. The greatest improvements were associated with academic, self-esteem, or social function outcomes. A majority of outcomes improved regardless of age of treatment initiation (60%–75%) or treatment duration (62%–72%). Studies with short treatment duration had shorter follow-up times (mean 3.2 years total study length) than those with longer treatment durations (mean 7.1 years total study length). Studies with follow-up times <3 years reported benefit with treatment for 93% of outcomes, whereas those with follow-up times ≥3 years reported treatment benefit for 57% of outcomes. Post-hoc analysis indicated that this result was related to the measurement of outcomes at longer periods (3.2 versus 0.4 years) after treatment cessation in studies with longer total study length.

Conclusions

While the majority of long-term outcomes of ADHD improve with all treatment modalities, the combination of pharmacological and non-pharmacological treatment was most consistently associated with improved long-term outcomes and large effect sizes. Older treatment initiation age or longer durations did not markedly affect proportion of improved outcomes reported, but measurement of outcomes long periods after treatment cessation may attenuate results.

A systematic review and analysis of long-term outcomes in attention deficit hyperactivity disorder: effects of treatment and non-treatment

BACKGROUND

In childhood, attention deficit/hyperactivity disorder (ADHD) is characterized by age-inappropriate levels of inattentiveness/disorganization, hyperactivity/impulsiveness, or a combination thereof. Although the criteria for ADHD are well defined, the long-term consequences in adults and children need to be more comprehensively understood and quantified. We conducted a systematic review evaluating the long-term outcomes (defined as 2 years or more) of ADHD with the goal of identifying long-term outcomes and the impact that any treatment (pharmacological, non-pharmacological, or multimodal) has on ADHD long-term outcomes.

METHODS

Studies were identified using predefined search criteria and 12 databases. Studies included were peer-reviewed, primary studies of ADHD long-term outcomes published between January 1980 to December 2010. Inclusion was agreed on by two independent researchers on review of abstracts or full text. Published statistical comparison of outcome results were summarized as poorer than, similar to, or improved versus comparators, and quantified as percentage comparisons of these categories.

RESULTS

Outcomes from 351 studies were grouped into 9 major categories: academic, antisocial behavior, driving, non-medicinal drug use/addictive behavior, obesity, occupation, services use, self-esteem, and social function outcomes. The following broad trends emerged: (1) without treatment, people with ADHD had poorer long-term outcomes in all categories compared with people without ADHD, and (2) treatment for ADHD improved long-term outcomes compared with untreated ADHD, although not usually to normal levels. Only English-language papers were searched and databases may have omitted relevant studies.

CONCLUSIONS

This systematic review provides a synthesis of studies of ADHD long-term outcomes. Current treatments may reduce the negative impact that untreated ADHD has on life functioning, but does not usually 'normalize' the recipients.

Mental disorders as risk factors for later substance dependence: estimates of optimal prevention and treatment benefits

BACKGROUND

Although mental disorders have been shown to predict subsequent substance disorders, it is not known whether substance disorders could be cost-effectively prevented by large-scale interventions aimed at prior mental disorders. Although experimental intervention is the only way to resolve this uncertainty, a logically prior question is whether the associations of mental disorders with subsequent substance disorders are strong enough to justify mounting such an intervention. We investigated this question in this study using simulations to estimate the number of substance disorders that might be prevented under several hypothetical intervention scenarios focused on mental disorders.

METHOD

Data came from the National Comorbidity Survey Replication (NCS-R), a nationally representative US household survey that retrospectively assessed lifetime history and age of onset of DSM-IV mental and substance disorders. Survival analysis using retrospective age-of-onset reports was used to estimate associations of mental disorders with subsequent substance dependence. Simulations based on the models estimated effect sizes in several hypothetical intervention scenarios.

RESULTS

Although successful intervention aimed at mental disorders might prevent some proportion of substance dependence, the number of cases of mental disorder that would have to be treated to prevent a single case of substance dependence is estimated to be so high that this would not be a cost-effective way to prevent substance dependence (in the range 76-177 for anxiety-mood disorders and 40-47 for externalizing disorders).

CONCLUSIONS

Treatment of prior mental disorders would not be a cost-effective way to prevent substance dependence. However, prevention of substance dependence might be considered an important secondary outcome of interventions for early-onset mental disorders.