Chronic depression, also known as major depressive disorder (MDD), can have various causes, including endocrinologic factors. Endocrinologic causes refer to disturbances in the endocrine system, which is responsible for producing and regulating hormones in the body. If a depression goes on more than 6 months, a possible underlying disease should be considered. Some endocrinologic causes of chronic depression include:

1. **Thyroid disorders**: Both hypothyroidism (underactive thyroid) and hyperthyroidism (overactive thyroid) can lead to depressive symptoms. Hypothyroidism, in particular, is often associated with fatigue, low energy, and depressed mood.

2. **Adrenal gland disorders**: Conditions affecting the adrenal glands, such as Addison’s disease (adrenal insufficiency) or Cushing’s syndrome (excess cortisol production), can lead to mood disturbances, including depression.

3. **Hypoglycemia**: Low blood sugar levels, often associated with conditions like diabetes or reactive hypoglycemia, can contribute to mood swings and depressive symptoms.

4. **Hypopituitarism**: This condition involves reduced hormone production by the pituitary gland, which can lead to hormonal imbalances affecting mood regulation.

5. **Menopausal hormonal changes**: Fluctuations in estrogen and progesterone levels during perimenopause and menopause can contribute to mood changes and depression in some women.

6. **Polycystic ovary syndrome (PCOS)**: Women with PCOS may experience hormonal imbalances, including elevated androgen levels and insulin resistance, which can increase the risk of depression.

7. **Sex hormone imbalances**: Low testosterone levels in men and women can contribute to depressive symptoms. Additionally, fluctuations in estrogen and progesterone levels during the menstrual cycle can affect mood in some women.

8. **Neurotransmitter dysregulation**: While not strictly an endocrinologic cause, disruptions in neurotransmitter levels, such as serotonin and dopamine, can influence mood regulation and contribute to depression.

It’s important to note that while these endocrinologic factors can contribute to depression, they are often just one piece of a complex puzzle. Depression is a multifaceted condition influenced by genetic, environmental, psychological, and social factors as well. If you suspect that an endocrine disorder may be contributing to your depression, it’s crucial to consult a healthcare professional for proper evaluation and management.