Maternal Thyroid Anomalies and Attention-Deficit Hyperactivity Disorder in Progeny

Area of Science:

• Endocrinology
• Neurodevelopmental Disorders
• Epidemiology

Background:

• Previous studies suggested maternal thyroid issues may cause ADHD in offspring.
• Clinical trials found levothyroxine ineffective for preventing neurodevelopmental impairments.

Purpose of the Study:

• To investigate the relationship between maternal thyroid conditions, thyroid hormone levels, medication use, and ADHD in offspring.
• To explore potential causal links and confounding factors.

Main Methods:

• Utilized a large Israeli cohort of 385,542 singleton births (1999-2012).
• Employed Cox proportional hazards models for analysis.
• Examined maternal hypothyroidism diagnosis, gestational thyroid hormone levels, and levothyroxine use.

Main Results:

• Maternal hypothyroidism diagnosis showed an association with increased ADHD risk (aHR=1.14).
• This association persisted regardless of gestational levothyroxine use or maternal thyroid hormone levels.
• Associations with gestational TSH and hypothyroxinemia were observed, but primarily in mothers without other thyroid diagnoses.

Conclusions:

• Maternal thyroid hypofunction is associated with ADHD in offspring, but likely not a direct causal link.
• Maternal thyroid dysfunction may indicate other factors affecting neurodevelopment independently of thyroid hormones.
• Further research should examine thyroid-disrupting factors for independent ADHD-related effects.