A total of 58 studies were included in the review (n at least 2,538).
Stimulant studies (20 studies): Compared with placebo, methylphenidate was considered efficacious for treating ADHD symptoms (four studies). There was little evidence to suggest that psychostimulants improved long-term interpersonal relationships (three studies).
Non-stimulant studies (four studies): An improvement in hyperactive and impulsive behaviour was observed following treatment with α-2 agonists (two studies). There was an improvement in hyperactive, impulsive and inattentive symptoms following treatment with atomoxetine (one study) and improved attention span following fluoxetine (one study).
Parent training (15 studies): Controlled study (eight studies) findings were mixed: improvements in ADHD symptoms were observed among preschool children in some studies (three studies); in others there was no improvement in hyperactive, impulsive and/or inattentive symptoms (five studies). Some case-series studies (three studies) reported improvements in ADHD symptoms.
Child training (six studies): All studies reported improved task-related attention and ability to delay activities and decreased disruptive behaviours. Gains were maintained two weeks (one study) and 22.5 weeks (one study) after the intervention.
Elimination diets (nine studies): Some evidence was found to support the use of an additive-free diet in preschool children with ADHD; there was no support for a sugar-free diet (four studies) or few-foods diet (four studies). Dietary elimination interventions were considered more suitable for preschoolers because of greater diet control by caregivers.
Nutritional support (two studies): Improvements in ADHD symptoms in children with low serum ferritin levels were reported following iron supplementation (one study).
Vestibular stimulation (two studies): Improvements in ADHD were noted compared with a sham condition (two studies).