How to manage thyrotoxicosis in children with Attention Deficit Hyperactivity Disorder (ADHD)?

From the Guidelines

Managing thyrotoxicosis in children with ADHD requires careful coordination between endocrine and psychiatric care, with the primary approach involving treating the thyrotoxicosis with standard therapies while adjusting ADHD medications as needed. For thyrotoxicosis, initial treatment typically includes beta-blockers such as propranolol (1-2 mg/kg/day divided into 2-3 doses) to control sympathetic symptoms, followed by antithyroid medications like methimazole (0.2-0.5 mg/kg/day divided into 1-3 doses) 1. Carbimazole (0.5-1.0 mg/kg/day) is an alternative in some countries.

Key Considerations

• ADHD stimulant medications (methylphenidate, amphetamine derivatives) should be used cautiously as they may exacerbate tachycardia and hypertension already present in thyrotoxicosis.
• Consider temporarily reducing stimulant dosage or switching to non-stimulant alternatives like atomoxetine (0.5-1.2 mg/kg/day) or guanfacine (1-4 mg daily) until thyroid function normalizes, as suggested by guidelines for ADHD management 1.
• Close monitoring is essential, with thyroid function tests every 2-4 weeks initially, then every 2-3 months once stabilized.
• Watch for potential drug interactions, particularly between propranolol and stimulants.
• The overlap in symptoms between thyrotoxicosis and ADHD (hyperactivity, attention problems, emotional lability) can complicate diagnosis and treatment assessment, so regular evaluation of both conditions is necessary, in line with recommendations for managing chronic conditions like ADHD 1.

Treatment Approach

• For preschool-aged children (age 4 years to the sixth birthday) with ADHD, evidence-based PTBM and/or behavioral classroom interventions should be prescribed as the first line of treatment, if available, with methylphenidate considered if these interventions do not provide significant improvement 1.
• For elementary and middle school-aged children (age 6 years to the 12th birthday) with ADHD, FDA-approved medications for ADHD should be prescribed along with PTBM and/or behavioral classroom intervention.
• For adolescents (age 12 years to the 18th birthday) with ADHD, FDA-approved medications for ADHD should be prescribed with the adolescent’s assent, and evidence-based training interventions and/or behavioral interventions should be considered as treatment, if available 1.

Monitoring and Adjustment

• The PCC should titrate doses of medication for ADHD to achieve maximum benefit with tolerable side effects, as recommended by guidelines for ADHD treatment 1.
• After detecting possible comorbid conditions, if the PCC is not trained or experienced in making the diagnosis or initiating treatment, the patient should be referred to an appropriate subspecialist to make the diagnosis and initiate treatment 1.

From the Research

Management of Thyrotoxicosis in Children with ADHD

• Thyrotoxicosis in children with Attention Deficit Hyperactivity Disorder (ADHD) requires careful management, as thyroid abnormalities can impact attentional functioning and behavior 2, 3.
• Studies have shown that thyroid hormone concentrations can be associated with mood symptoms, attention problems, and hyperactivity in children with ADHD 4, 5.
• In children with ADHD and resistance to thyroid hormone (RTH), supraphysiological doses of liothyronine (L-T3) may be beneficial in reducing hyperactivity and impulsivity 6.
• However, in children with ADHD without RTH, L-T3 treatment may have no effect or may be detrimental 6.
• Routine thyroid hormone screening is not indicated in children with non-familial ADHD, as the prevalence of thyroid hormone abnormalities is similar to that in the general population 3.

Thyroid Function and ADHD

• Thyroid function tests have been used to evaluate the relationship between thyroid hormone concentrations and neurocognitive functioning in children with ADHD 4, 2.
• Studies have found that thyroid abnormalities are uncommon in children referred for ADHD, but that thyroxine concentrations within the normal range can be differentially associated with ADHD subtypes and mood symptoms 4, 2.
• Hyperthyroidism has been shown to disrupt attentional processing in children, particularly in the shift and disengage functions of attentional processing 5.

Treatment Considerations

• Treatment of thyrotoxicosis in children with ADHD should be individualized, taking into account the child's specific thyroid hormone profile and ADHD symptoms 6, 5.
• Close monitoring of thyroid function and ADHD symptoms is necessary to adjust treatment as needed 6, 3.
• Further research is needed to fully understand the relationship between thyroid function and ADHD, and to develop effective treatment strategies for managing thyrotoxicosis in children with ADHD 4, 2.