Altered attention networks in patients with thyroid dysfunction: A neuropsychological study

Area of Science:

• Neuroscience
• Endocrinology
• Psychiatry

Background:

• Thyroid dysfunction is common and can affect cognitive functions.
• Attention networks, including alertness, orientation, and executive control, are crucial for cognitive performance.
• Previous research has suggested links between thyroid hormones and cognitive function, but specific attention network deficits in different thyroid states require further investigation.

Purpose of the Study:

• To investigate the impact of different types of thyroid dysfunction (hypothyroidism, subclinical hypothyroidism, hyperthyroidism, subclinical hyperthyroidism) on attention networks.
• To explore the relationship between thyroid hormone levels, attention network efficiency, and psychological factors like anxiety and depression.

Main Methods:

• Recruited patients with diagnosed thyroid dysfunction and euthyroid controls.
• Administered the Attention Network Test (ANT) to assess alertness, orientation, and executive control.
• Collected data on anxiety and depression scores (Hamilton Anxiety Scale, HAMD).
• Utilized covariance analysis and correlation analyses to examine relationships between variables.

Main Results:

• Hypothyroidism was associated with deficits in the alerting network.
• Hyperthyroidism was linked to impairments in both alerting and executive control networks.
• No significant attention network deficits were observed in subclinical hypothyroidism or subclinical hyperthyroidism.
• Patients with thyroid dysfunction exhibited higher anxiety and depression scores than controls.
• Executive control network efficiency showed a negative correlation with T4 levels in hypothyroidism and a positive correlation in hyperthyroidism.
• A significant quadratic U-shaped relationship was found between T4/T3 levels and executive control network efficiency across all participants.

Conclusions:

• Thyroid dysfunction, particularly overt hypothyroidism and hyperthyroidism, significantly affects specific attention networks.
• Subclinical thyroid dysfunction does not appear to impair attention networks.
• While thyroid dysfunction is associated with increased anxiety and depression, these psychological factors do not explain the observed attention network differences between groups.
• Thyroid hormone levels have a complex, non-linear relationship with executive control network efficiency.