Depression

Laboratory tests

• FBCif neededDepending on the clinical examination. The HAS sets no list in first-line care ^[2,3]. The HAS long-term condition (ALD) document on recurrent or persistent forms cites the blood count in the initial tests ^[4]. A Geneva first-line protocol places it in its standard tests ^[5].
• Serum electrolytesif neededDepending on the clinical examination, or before starting an antidepressant. The HAS sets no list in first-line care ^[2,3]. The HAS long-term condition (ALD) document on recurrent or persistent forms cites serum sodium and potassium in the initial tests ^[4]. A Geneva first-line protocol sees a use for it when starting treatment ^[5].
• Serum creatinine with eGFRif neededDepending on the clinical examination, or before starting an antidepressant. The HAS sets no list in first-line care ^[2,3]. The HAS long-term condition (ALD) document on recurrent or persistent forms cites serum creatinine in the initial tests ^[4]. A Geneva first-line protocol sees a use for it when starting treatment ^[5].
• Serum calciumif needednon-French guidelineDepending on the clinical examination. A Geneva first-line protocol places serum calcium in its standard tests, looking for a somatic cause ^[5]. The HAS sets no list in first-line care ^[2,3]. The HAS long-term condition (ALD) document does not cite it ^[4].
• Serum albuminif neededLooking for undernutrition in older people, or correcting a serum calcium. The HAS long-term condition (ALD) document on recurrent or persistent forms cites it in the initial tests ^[4].
• TSHif neededHypothyroidism is among the causes to consider first ^[2]. The HAS working group (2017) chose not to cite thyroid tests as an example ^[3]; its long-term condition (ALD) document on recurrent or persistent forms cites TSH in the initial tests ^[4].
• Fasting plasma glucoseif needednon-French guidelineDepending on the clinical examination. A Geneva first-line protocol places plasma glucose in its standard tests, looking for a somatic cause ^[5]. The HAS sets no list in first-line care ^[2,3]. The HAS long-term condition (ALD) document does not cite it ^[4].
• ASTif neededDepending on the clinical examination, or before starting an antidepressant. The HAS sets no list in first-line care ^[2,3]. The HAS long-term condition (ALD) document on recurrent or persistent forms cites transaminases and GGT in the initial tests ^[4]. A Geneva first-line protocol sees a use for it when starting treatment ^[5].
• ALTif neededDepending on the clinical examination, or before starting an antidepressant. The HAS sets no list in first-line care ^[2,3]. The HAS long-term condition (ALD) document on recurrent or persistent forms cites transaminases and GGT in the initial tests ^[4]. A Geneva first-line protocol sees a use for it when starting treatment ^[5].
• GGTif neededDepending on the clinical examination, or before starting an antidepressant. The HAS sets no list in first-line care ^[2,3]. The HAS long-term condition (ALD) document on recurrent or persistent forms cites transaminases and GGT in the initial tests ^[4]. A Geneva first-line protocol sees a use for it when starting treatment ^[5].
• urine drug screenif neededSuspected use, abuse, dependence or withdrawal of psychoactive substances, which can mimic or induce depression or be associated with it ^[2]. Code 0659 reimbursed in France only for emergency diagnosis or therapeutic monitoring: otherwise, NR (not reimbursable in France) ^[6].
• Vitamin B12 (if pernicious anaemia suspected)if needednon-French guidelineSuspected pernicious anaemia: in the United States, an American Family Physician review recalls that it can present with mood disorders and insomnia, and includes vitamin B12 measurement in the baseline tests, especially in older people (authors' opinion, no grading of the level of evidence) ^[7]. The HAS gives no list of tests ^[3]; the Geneva protocol cites vitamin B12 hypovitaminosis among the differential diagnoses, without including it in its standard tests ^[5].