VHOSPITAL.CLINIC · Differential Diagnosis
Depression vs Hypothyroidism
Clinical comparison — shared symptoms, key differences, distinguishing diagnostic tests, treatment pathways, and when to seek urgent evaluation.
Condition Overview
Condition A
Depression
Depression is a common and serious mood disorder causing persistent feelings of sadness, hopelessness, and loss of interest in activities. It affects how a person thinks, feels, and handles daily activities. Effective treatments include therapy and medication.
Condition B
Hypothyroidism
Hypothyroidism occurs when the thyroid gland doesn't produce enough thyroid hormone. This slows metabolism and causes fatigue, weight gain, cold intolerance, constipation, and depression. Hashimoto's thyroiditis is the most common cause.
Shared Symptoms — Why They're Confused
Both conditions present with 3 overlapping symptoms, making clinical differentiation essential.
Key Clinical Differences
Depression
- Persistent low mood, fatigue, cognitive slowing
- Psychomotor retardation
- Weight gain
- Sleep disturbance
Hypothyroidism
- Weight gain with cold intolerance and constipation
- Dry skin, hair loss, bradycardia
- Periorbital oedema and hoarse voice
- Biochemical: elevated TSH, low free T4
Distinguishing Diagnostic Tests
| Test | Depression | Hypothyroidism |
|---|---|---|
| TSH + free T4 | Normal — thyroid function intact; depression is primary | Elevated TSH + low fT4 — primary hypothyroidism confirmed |
| Clinical features | Anhedonia, suicidal ideation, diurnal variation, psychosocial stressors | Cold intolerance, constipation, periorbital oedema, dry coarse skin |
| Response to thyroid replacement | No improvement in mood with levothyroxine | Depression lifts with adequate levothyroxine therapy |
Treatment Approaches
Depression
- •SSRIs or SNRIs first-line
- •Psychotherapy (CBT)
- •If non-responsive: mirtazapine, venlafaxine, augmentation
Hypothyroidism
- •Levothyroxine titrated to normal TSH
- •Symptoms resolve over weeks to months
- •Annual TSH monitoring
- •Avoid over-treatment (AF risk)
When Doctors Consider Each Diagnosis
🔵 Consider Depression when:
- →Anhedonia, hopelessness, diurnal variation, psychosocial context, normal TSH
🟢 Consider Hypothyroidism when:
- →Cold intolerance, constipation, bradycardia, periorbital puffiness, elevated TSH
Explore Each Condition in Detail
Related Clinical Pages
Depression
Medical References
Content on this page is informed by evidence-based clinical sources including:
- World Health Organization (WHO)Global health guidance and disease classification
- National Health Service (NHS)UK clinical guidelines and patient information
- National Institute for Health and Care Excellence (NICE)Evidence-based clinical practice guidelines
- Centers for Disease Control and Prevention (CDC)US public health data and clinical recommendations
- PubMed – NCBIPeer-reviewed biomedical literature and clinical studies
- Cochrane LibrarySystematic reviews and meta-analyses in evidence-based medicine
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