From the Research
Basic medical screening labs to assess for medical contributors to depression should include a complete blood count (CBC), comprehensive metabolic panel (CMP), thyroid-stimulating hormone (TSH), vitamin B12, folate, and vitamin D levels. These tests help identify common physiological conditions that can manifest as depressive symptoms. The CBC can detect anemia, which often presents with fatigue and low mood 1. The CMP evaluates kidney and liver function, electrolyte balance, and glucose levels, as abnormalities in these areas can affect brain function and mood. Thyroid dysfunction, particularly hypothyroidism, frequently mimics depression, making TSH testing essential. Deficiencies in B12, folate, and vitamin D are strongly associated with depressive symptoms and are easily treatable with supplementation. For B12 deficiency, typical replacement involves 1000 mcg daily orally or monthly injections if absorption is impaired. Vitamin D supplementation often requires 1000-2000 IU daily when levels are low.
Some key points to consider when assessing for medical contributors to depression include:
- The importance of screening for depression in primary care settings, as recommended by the USPSTF and American Academy of Family Physicians 2
- The use of validated screening tools, such as the Patient Health Questionnaire-9 (PHQ-9), to identify patients with depression 3
- The potential for inflammatory markers, such as C-reactive protein, to contribute to depression, and the consideration of screening for infections like syphilis, HIV, or hepatitis C in certain populations 1
- The need for timely treatment and follow-up, as emphasized in studies on the impact of systematic depression screening in primary care 4
Additional tests to consider include inflammatory markers like C-reactive protein, as chronic inflammation can contribute to depression, and in certain populations, screening for syphilis, HIV, or hepatitis C may be warranted as these infections can affect mental health. These laboratory evaluations should be conducted before or concurrent with psychiatric treatment to ensure that potentially reversible medical causes of depression are not overlooked.