Medical Conditions That Can Mimic Depression: What Clinicians Check
Author: Angela Bogdanova · Published: October 8, 2026 · Editorial Policy
Research cluster: Depression & Depressive Disorders · Written by Artificial Sapiens
Depressive symptoms can emerge from several paths. A person who feels exhausted, unable to concentrate, emotionally flat, slowed down, or unusually withdrawn may have a depressive disorder, a medical illness with overlapping manifestations, a medication effect, or more than one of these at the same time. A careful assessment investigates those possibilities together. Thyroid disease, anemia, vitamin B12 deficiency, sleep disorders, endocrine changes, neurological disease, systemic illness, and some treatments deserve consideration when the history or examination points toward them. NIMH · NICE depression guideline
The question clinicians ask is specific: which findings explain this person's symptoms, which findings require targeted medical investigation, and what evidence would support a depressive disorder occurring alongside a physical condition? There is no single blood test for major depressive disorder and no universal laboratory panel that clears every medical explanation. A thoughtful medical rule-out is a clinical process rather than a checklist ordered indiscriminately. AAFP · VA/DoD MDD guideline
I. What Does It Mean for a Medical Condition to Mimic Depression?
A medical condition may resemble depression by producing symptoms that also occur in depressive episodes: fatigue, changes in sleep or appetite, reduced activity, difficulty thinking, psychomotor slowing, irritability, or diminished interest in usual activities. Some illnesses also produce substantial sadness or loss of pleasure. The resemblance may be strong enough to trigger a positive screening questionnaire even when the central clinical problem lies elsewhere. NIMH · NICE NG222
Four clinical relationships matter. First, a bodily illness may account for many depression-like symptoms through a direct physiological process. Second, a chronic disease may contribute to the development of a genuine depressive episode through pain, inflammation, functional loss, treatment burden, or other interacting mechanisms. Third, a person may have both an independent depressive disorder and a medical condition. Fourth, a medication or substance, including withdrawal from one, may contribute to a new mood or energy disturbance. These relationships require different treatment decisions and can coexist. NIMH: Chronic Disease and Depression · NICE CG91
The distinction between depressed mood, a depressive symptom, a major depressive episode, and major depressive disorder is essential. Depressed mood is an emotional state. A depressive symptom may arise from several causes. A major depressive episode is a clinical syndrome defined by its symptom pattern, duration, distress, impairment, and exclusion considerations; major depressive disorder involves a diagnostic history that also assesses manic or hypomanic episodes and other explanations. A screening result is a prompt for assessment. NIMH · NICE NG222
Read our broader account of depression diagnosis and clinical evaluation for the diagnostic interview, impairment, episode history, and risk assessment. This page concentrates on the medical differential: symptoms, clues, and appropriate investigations.
II. How Clinicians Decide What to Investigate
1. The timeline comes first
Clinicians ask when the mood, cognitive, sleep, and energy changes began, whether symptoms arrived abruptly or gradually, and whether they followed an infection, an operation, a medication change, a new endocrine symptom, or worsening of a known illness. They review whether low mood or loss of pleasure predates the physical changes, accompanies them, or persists after a medical problem has improved. Temporal association raises a possibility; it is not proof of causation. NICE NG222 · AAFP
A sudden decline over hours or days with disorientation, impaired attention, fluctuating awareness, fever, or neurological findings calls for a different and often urgent medical assessment. Delirium and acute illness should not be interpreted as ordinary depressive slowing. A progressive change in memory, executive abilities, movement, or personality also changes the differential. NICE NG222 · AAFP
2. Review the entire symptom pattern
Mood and anhedonia are assessed alongside cold or heat intolerance, constipation, menstrual changes, weight changes, palpitations, thirst, urinary frequency, pain, snoring, witnessed breathing pauses, daytime sleepiness, numbness, gait changes, headaches, new weakness, and symptoms after exertion. Each associated feature can direct the next examination or test. The absence of a particular physical clue does not always rule out disease. American Thyroid Association · NICE vitamin B12 guideline · NIDDK: Hyperparathyroidism
3. Examine medical history, treatments, and exposures
Medical history covers thyroid disorders, anemia, kidney and liver disease, diabetes, chronic infection, neurological illness, sleep conditions, inflammatory disease, and relevant reproductive transitions. The medication history includes prescription drugs, nonprescription products, supplements, alcohol, recreational substances, and changes in use or discontinuation. Family history and previous depressive or manic/hypomanic episodes may alter the assessment. NICE NG222 · NICE CG91
4. Perform a focused examination and plan tests
Vital signs and physical and neurological findings can make particular causes more or less likely. The clinician may evaluate thyroid findings, pallor, hydration, reflexes, peripheral sensation, gait, cognitive status, or signs of systemic disease. Laboratory and other investigations should answer a defined clinical question; results are interpreted with symptoms, medication history, and pretest probability. AAFP · VA/DoD guideline
III. Thyroid Disorders and Other Endocrine Causes
1. Hypothyroidism
An underactive thyroid can produce fatigue, slowed thinking, forgetfulness, low mood, constipation, cold intolerance, dry skin, and changes in weight or menstrual patterns. These overlapping symptoms are a classic reason to consider thyroid testing during an evaluation for depression-like symptoms. Symptoms alone cannot diagnose hypothyroidism, and many people with depression have normal thyroid function. American Thyroid Association · NIDDK: Hypothyroidism
When clinical suspicion warrants testing, thyroid-stimulating hormone (TSH) is a common initial measurement; free thyroxine (free T4) helps characterize an abnormal or clinically discordant result. The exact sequence depends on context, including known thyroid disease, pregnancy-related circumstances, medications, and the possibility of pituitary disease. Treating true hypothyroidism addresses a medical disorder, while a co-occurring depressive episode may also need direct care. American Thyroid Association · AAFP
2. Hyperthyroidism and thyroid treatment changes
An overactive thyroid more often produces agitation, anxiety, heat intolerance, tremor, palpitations, weight loss, and sleep disturbance, but exhaustion and mood symptoms can blur the picture. Changes in thyroid replacement doses can also modify energy, sleep, and emotional state. The clinician uses the history, examination, and relevant thyroid function testing to interpret these patterns. AAFP · American Thyroid Association
3. Hypercalcemia and primary hyperparathyroidism
Abnormally high calcium levels may accompany fatigue, low mood, muscle weakness, constipation, thirst, urinary changes, cognitive difficulty, or confusion. Primary hyperparathyroidism is one possible cause of hypercalcemia, but many cases are initially asymptomatic. A calcium test may be useful when associated symptoms or clinical findings make it relevant; an abnormal result prompts an investigation of the underlying cause, potentially including parathyroid hormone. NIDDK: Primary Hyperparathyroidism
4. Cortisol disorders and Cushing syndrome
Excess glucocorticoid activity can involve mood and cognitive changes along with characteristic systemic findings. Red flags for Cushing syndrome include muscle weakness, easy bruising, wide purplish stretch marks, changes in fat distribution, high blood pressure, or high blood glucose. These findings justify a directed endocrine assessment. Routine cortisol screening for everyone reporting depressed mood would be inappropriate. Exogenous steroid exposure must be reviewed carefully. Endocrine Society
5. Diabetes and other metabolic disorders
Glucose disturbances can contribute to low energy, poor concentration, sleep disruption, thirst, and changes in weight. Diabetes also increases the burden of chronic disease management, and depression can coexist independently. A clinician may use glucose or HbA1c testing when history, symptoms, or established preventive-care indications warrant it. A laboratory finding should be understood in its clinical context rather than treated as an automatic explanation for mood changes. NIMH: Chronic Disease and Depression · AAFP
IV. Anemia, Vitamin Deficiencies, and Nutritional Problems
1. Anemia and iron deficiency
Anemia can cause fatigue, weakness, reduced physical stamina, shortness of breath on exertion, lightheadedness, palpitations, and cognitive difficulty. A person may describe the resulting loss of capacity as feeling depressed. Iron deficiency may be associated with blood loss, dietary issues, or absorption problems, and should be evaluated according to its cause and laboratory findings. A complete blood count (CBC) can identify anemia; ferritin and other iron studies are chosen when iron deficiency is plausible. AAFP
A normal hemoglobin value does not by itself settle every nutritional question, and a low hemoglobin value does not establish that anemia explains an entire depressive syndrome. The clinician examines whether physical symptoms, psychological symptoms, and laboratory abnormalities change together and whether another diagnosis still needs attention. NICE NG222 · AAFP
2. Vitamin B12 deficiency
Vitamin B12 deficiency can present with fatigue, memory or concentration difficulties, depressive symptoms, and neurological problems such as numbness, altered sensation, imbalance, or gait disturbance. Importantly, NICE specifically advises that absence of anemia or macrocytosis does not by itself exclude B12 deficiency. Testing is based on symptoms, relevant risk factors, and clinical judgment; B12 deficiency should not be inferred from mood alone. NICE NG239
Risk factors can include certain gastrointestinal operations, malabsorption conditions, restrictive diets, and medications associated with altered B12 absorption. Depending on the circumstances and initial result, further evaluation may be needed. Early identification matters because neurological complications deserve medical attention. B12 replacement treats deficiency; it is not an evidence-based substitute for treating major depressive disorder in someone whose B12 status is normal. NICE NG239
3. Folate, other nutrient problems, and indiscriminate supplements
Folate deficiency and other nutritional conditions can contribute to anemia or nonspecific health symptoms, particularly in settings of restricted intake, malabsorption, or chronic disease. The appropriate test depends on symptoms and medical risk. Broad vitamin panels and high-dose supplement regimens have limited justification when there is no specific clinical indication. Laboratory results also require careful interpretation: an abnormal value may be associated with illness without being the sole cause of low mood. AAFP · NICE NG239
V. Sleep Disorders That Can Look Like Depression
1. Obstructive sleep apnea
Obstructive sleep apnea can cause fragmented sleep, excessive daytime sleepiness, fatigue, impaired attention, and reduced quality of life. Some people report irritability or low mood. Clues include loud habitual snoring, witnessed breathing pauses, waking with gasping or choking, hypertension, and daytime sleepiness. The absence of a typical appearance or stereotype does not exclude the condition. American Academy of Sleep Medicine guideline
The American Academy of Sleep Medicine recommends a comprehensive sleep evaluation followed by appropriate objective testing when sleep apnea is suspected. Polysomnography or, for selected uncomplicated adults, home sleep apnea testing may be appropriate. A questionnaire alone cannot diagnose sleep apnea, and a negative or technically inadequate home test may need follow-up with polysomnography. AASM
2. Insomnia, insufficient sleep, and circadian disruption
Chronic insomnia, shortened sleep opportunity, irregular sleep schedules, shift work, and circadian mismatch can impair mood, energy, attention, and motivation. They may also coexist with and aggravate depressive disorders. Clinicians ask about sleep quantity, timing, quality, daytime impairment, breathing symptoms, medications, and substance use rather than assuming that every sleep complaint is secondary to depression. NICE NG222 · AASM
3. What improvement with sleep treatment means
Improvement in fatigue and cognitive performance after treating a sleep condition supports an important contribution from that condition. Persistent low mood, anhedonia, hopelessness, or impairment may still merit direct depression assessment. Patients can require coordinated sleep and mental-health care because sleep disease and depressive syndromes frequently interact. NIMH: Chronic Disease and Depression · NICE NG222
VI. Medications, Alcohol, and Other Substances
1. Medication effects deserve individual review
Some drugs can contribute to fatigue, disturbed sleep, cognitive slowing, agitation, or depressive symptoms. Among categories worth carefully reviewing are systemic corticosteroids, some immune-modulating therapies, certain hormonal treatments, sedating medications, and substances affecting the central nervous system. Evidence for a direct depression-causing effect varies greatly by drug; an association in observational reports does not establish causation for an individual patient. Systematic review of drug-induced depression · NICE NG222
A careful review documents the exact product, dose, start date, dose changes, interactions, and whether symptoms track exposure. Clinicians may investigate an adverse effect, adjust therapy, or choose another treatment when appropriate, considering the risks of stopping the drug and the consequences of the illness it treats. Never abruptly discontinue prescription corticosteroids, psychiatric medications, anticonvulsants, or other long-term therapies without a clinician-directed plan. Endocrine Society · NICE NG222
2. Not every medication suspected online is proven to cause depression
Claims about beta-blockers, hormonal contraceptives, acne medications, and numerous common treatments often exceed what the evidence supports. Some users experience mood changes, but the causal inference depends on the individual drug, the study design, the underlying condition, and alternative explanations. A medication review evaluates these distinctions rather than treating an entire drug class as universally depressogenic. Drug-induced depression systematic review
3. Alcohol, recreational drugs, intoxication, and withdrawal
Alcohol use, sedatives, stimulants, opioids, and other substances can influence sleep, motivation, mood, cognition, and daily functioning. Withdrawal and changes in consumption may also produce symptoms that resemble or complicate depression. Assessment should include timing, quantity, and safety, while also evaluating whether a primary depressive disorder is present. NICE NG222 · VA/DoD guideline
VII. Neurological and Cognitive Conditions
1. Parkinson disease, stroke, seizures, and other neurological disorders
Neurological conditions may involve fatigue, movement slowing, apathy, altered attention, reduced facial expression, and changes in emotional regulation. Parkinson disease, stroke, and seizure disorders can be accompanied by depressive symptoms or by clinical depression. Findings such as unilateral weakness, new tremor, gait disturbance, altered speech, unusual episodic events, or focal neurological changes deserve targeted neurological evaluation. NIMH: Chronic Disease and Depression · AAFP
Apathy, loss of motivation, and slowed movement should be distinguished carefully from sadness, guilt, hopelessness, and anhedonia. These symptoms can overlap, and neurological illness does not immunize a person against genuine depression. NICE NG222 · NIMH
2. Cognitive decline versus depressive cognitive complaints
Poor concentration, slow processing, and perceived memory loss occur in depression, but progressive cognitive decline, disorientation, loss of practical skills, or fluctuating awareness require consideration of neurological and medical explanations. Older adults may have depression, a neurocognitive disorder, or both. Clinicians may seek collateral history with consent and arrange appropriate cognitive, medical, or specialist evaluation. AAFP · NICE NG222
The historical phrase 'pseudodementia' appears in some discussions of depression-related cognitive impairment, but it should not be used to promise that memory symptoms are harmless or completely reversible. The cause and course of cognitive symptoms need direct evaluation.
VIII. Chronic Illness, Infection, Inflammation, and Pain
1. Chronic kidney, liver, cardiac, and pulmonary disease
Chronic organ disease can contribute to fatigue, sleep disruption, pain, reduced exercise tolerance, cognitive problems, and substantial emotional strain. Depending on the history and examination, clinicians may investigate kidney function, electrolytes, liver enzymes, oxygenation, or cardiopulmonary symptoms. Abnormal organ-function tests identify questions that require their own evaluation; they do not automatically establish a causal explanation for a depressive episode. NIMH: Chronic Disease and Depression · AAFP
2. Pain, autoimmune disease, and cancer
Chronic pain and systemic illnesses such as inflammatory disorders or cancer can alter sleep, activity, appetite, and functioning, and may increase depression risk through multiple pathways. The psychological impact of being ill and direct biological processes can coexist. A person who is dealing with chronic illness can have a treatable depressive disorder at the same time; a complete assessment includes both physical management and mental-health care. NIMH: Chronic Disease and Depression · NICE CG91
3. Infection and post-infectious illness
Some infections produce persistent fatigue, cognitive complaints, appetite change, and low energy. HIV, syphilis, Lyme disease, and other infections warrant consideration when history, clinical findings, and relevant exposure make them plausible; routine testing for every possible infection in every patient with low mood creates false positives and confusion. The CDC specifically advises interpreting Lyme testing in relation to plausible exposure and compatible manifestations. CDC: Lyme Testing · AAFP
Long COVID can involve fatigue, brain fog, sleep problems, orthostatic symptoms, and post-exertional symptom exacerbation. These symptoms may overlap with a depression questionnaire, while the patient's illness requires its own clinical evaluation. CDC guidance states that no single laboratory test definitively diagnoses or excludes Long COVID and that care should not depend entirely on routine objective findings. Depressive symptoms may coexist and deserve evaluation on their own terms. CDC: Long COVID Clinical Guidance
4. The clinical meaning of inflammation
Inflammatory pathways are relevant to research on sickness behavior and depression, but inflammatory markers do not independently diagnose major depressive disorder or prove that a given patient has an inflammation-driven depressive syndrome. Tests such as C-reactive protein are ordered according to specific medical indications, rather than being treated as universal depression biomarkers. NIMH: Chronic Disease and Depression · VA/DoD guideline
IX. Hormonal Transitions and Reproductive Context
Perimenopause and menopause can be associated with disrupted sleep, hot flashes, changes in menstrual patterns, and mood symptoms. The timing and associated vasomotor symptoms help with assessment. NICE differentiates menopause-associated depressive symptoms that do not meet diagnostic criteria from diagnosed depression, which requires its own evidence-based treatment plan. Menopause identification for many otherwise healthy adults over age 45 is clinical rather than based on routine hormone panels. NICE menopause guideline
Pregnancy, the postpartum period, premenstrual patterns, and other reproductive contexts also influence differential assessment, medication safety, and treatment choices. Because these topics require distinct population-specific clinical guidance, they should be assessed in their dedicated care pathways rather than folded into a generic thyroid or hormone workup. NIMH · NICE NG222
X. Which Medical Tests May Be Considered?
There is no mandatory universal depression laboratory panel. The purpose of testing is to investigate clinically plausible medical explanations, establish relevant baseline health information, and address particular treatment-safety questions. A normal set of results can reduce concern about some conditions but cannot rule out every physical illness or confirm that depression is necessarily the only diagnosis. AAFP · NICE NG222
1. Complete blood count
A CBC evaluates red blood cells and other blood-count findings and may identify anemia or other abnormalities requiring follow-up. Clinicians consider it especially when fatigue, pallor, exertional breathlessness, bleeding history, dietary risk, or systemic illness suggests a hematologic issue. Iron studies may follow when indicated. AAFP
2. Thyroid function testing
TSH, with free T4 or additional testing where needed, evaluates suspected thyroid dysfunction. Features such as cold intolerance, constipation, unexplained weight change, tremor, palpitations, known thyroid disease, or a relevant medication history can increase its relevance. An isolated result must be interpreted using laboratory ranges and the clinical picture. American Thyroid Association · AAFP
3. Metabolic and organ-function tests
Electrolytes, calcium, glucose, kidney tests, and sometimes liver tests may be appropriate when symptoms, comorbidity, examination, or medication decisions suggest a metabolic or systemic issue. Hyponatremia and other electrolyte disturbances can contribute to weakness, confusion, or acute illness. A chemistry panel is a route to identifying selected abnormalities, not a test for depression itself. AAFP · NIDDK: Primary Hyperparathyroidism
4. Vitamin B12 and selected nutritional tests
B12 testing is considered when symptoms and risks suggest deficiency, especially neurological symptoms, unexplained fatigue, gastrointestinal disease or surgery, and associated medication or nutritional risk. NICE emphasizes that B12 deficiency can occur without anemia and that mental-health symptoms alone do not mandate universal B12 testing. Folate and iron studies likewise depend on a clinical indication. NICE NG239
5. HbA1c, infection testing, and other targeted investigations
Glucose or HbA1c can be appropriate when symptoms or diabetes screening criteria indicate a need. HIV or syphilis tests, Lyme serology, endocrine tests, imaging, and neurological investigations are selected on the basis of individual risk, exposure, symptoms, and examination. More testing is not necessarily better: low-pretest-probability testing can create misleading findings and unnecessary follow-up. CDC: Lyme Testing · AAFP
6. Sleep testing
A sleep study is considered when a focused sleep history supports sleep-disordered breathing or another condition that requires objective investigation. The selection of home sleep apnea testing versus laboratory polysomnography follows the patient's medical complexity and the sleep specialist's assessment. Screening questionnaires help prioritize evaluation but do not constitute a diagnosis. AASM
7. Why brain scans and broad hormone panels are not standard first steps
Neuroimaging, broad hormone panels, inflammatory biomarker batteries, and genetic tests are not universal diagnostic tests for depression. They are considered when findings such as new focal neurological deficits, severe cognitive changes, suspected endocrine syndromes, or other atypical features justify them. The clinically important question is what specific problem the test is intended to investigate and how its result will change care. NICE NG222 · AAFP
XI. Interpreting Results Without Missing Depression
An abnormal result may identify a treatable physical condition, but it is not proof that this condition caused every mood symptom. Conversely, normal laboratory tests do not invalidate fatigue, suffering, cognitive difficulties, or depression. The clinician reviews the degree of abnormality, relevance to symptoms, previous test results, the illness timeline, and the patient's response to treatment. NICE NG222 · NIMH
If hypothyroidism, anemia, B12 deficiency, sleep apnea, or another condition is confirmed, treatment should follow the appropriate medical guideline. Follow-up then examines which symptoms improve and which remain. Clinically important depressive symptoms may merit psychotherapy, medication, collaborative care, or specialist assessment even when a medical contributor has been identified. NICE CG91 · VA/DoD
For patients whose symptoms remain substantial, a diagnostic reassessment also reviews treatment adherence, side effects, sleep, substance exposure, psychosocial adversity, comorbid anxiety, and previous episodes. A medical differential is not completed once a single test result is reported. NICE NG222
For the full depression-specific care pathway, see Depression Treatment: Therapy, Medication, and Other Options.
XII. Bipolar Symptoms, Acute Mental Status Changes, and Safety
Before diagnosing unipolar major depressive disorder, a clinician should ask about periods of distinctly elevated or irritable mood accompanied by increased energy or activity, markedly decreased need for sleep, or other signs of hypomania or mania. These features can point to a bipolar-spectrum condition that requires separate assessment and treatment planning. They are different from ordinary insomnia and fatigue. NICE NG222
New hallucinations, delusions, rapidly worsening confusion, severe agitation, or inability to care for basic needs requires prompt professional assessment. Acute confusion, fever with altered awareness, sudden neurological weakness, seizure, or severe medical instability may warrant emergency medical care. These presentations should not be assigned a routine depression label without investigating immediate medical risks. NICE NG222 · AAFP
Clinicians evaluating depressive symptoms should ask directly about suicidal thoughts and intent and match follow-up to the person's actual risk. If someone is in immediate danger or has an imminent plan, seek emergency assistance now. In the United States, call or text 988 for suicide crisis support; call 911 for an immediate life-threatening emergency. This article supplies medical differential information and does not replace individualized crisis care. NICE NG222 · NIMH
XIII. How to Prepare for an Appointment
A useful appointment record includes when symptoms began, what changed immediately beforehand, patterns of fatigue and sleep, changes in weight or appetite, temperature intolerance, pain, menstrual or reproductive changes, unusual neurological symptoms, and previous relevant diagnoses. Include a complete medication and supplement list with recent dose changes, and note alcohol or other substance use. If available, bring prior relevant test results and sleep-study reports.
It is reasonable to ask the clinician which physical explanations fit the symptom pattern, which tests are indicated, how borderline or abnormal results will be interpreted, what other causes remain after testing, and when symptoms should be reassessed. Request clarification about the plan for depression-specific care if a physical condition is found. NICE NG222 · NICE CG91
Someone whose fatigue or cognition has been limiting functioning should not need to prove a single cause before receiving appropriate help. A structured evaluation can address medical illness, depressive disorder, sleep, medication safety, and psychosocial needs in parallel. NIMH: Chronic Disease and Depression
XIV. Common Questions
Can hypothyroidism look exactly like depression?
It can produce substantial overlapping fatigue, slowed thinking, sleep problems, and depressed mood. Signs such as cold intolerance, constipation, dry skin, or menstrual changes can increase suspicion. Thyroid testing clarifies thyroid function; it does not itself establish or exclude a depressive disorder. American Thyroid Association
Should every person with depression have a thyroid and vitamin B12 panel?
Testing is tailored to symptoms, risk factors, examination, health history, and the setting of care. Thyroid tests are often considered when depression-like symptoms occur; B12 testing is more specifically directed by features such as neurologic symptoms, risk factors, and unexplained fatigue. Routine testing of everyone for every condition is not supported. AAFP · NICE NG239
Does a positive PHQ-9 prove that I have depression?
No. A positive screening score indicates that a complete clinical assessment is appropriate. Fatigue, sleep disruption, poor concentration, and appetite changes can occur in both depressive and medical conditions. Read what a positive depression screening result means for the screening-versus-diagnosis distinction. NICE NG222
Can sleep apnea cause low mood and brain fog?
Sleep apnea may contribute to nonrestorative sleep, fatigue, daytime sleepiness, and impaired concentration. Depression may coexist. Objective sleep testing is used when clinical suspicion warrants it; a sleep questionnaire alone is not definitive. AASM
If a vitamin deficiency is found, will treatment cure my depression?
Treating a documented deficiency can improve symptoms attributable to it, although the response and timing vary. A genuine depressive disorder can persist or coexist, so follow-up should assess mood, interest, impairment, and safety as well as laboratory correction. NICE NG239 · NICE NG222
Can a prescription drug be responsible?
Yes, certain treatments can contribute to mood changes or symptoms that resemble depression. The evidence and magnitude of risk are drug-specific. A clinician should review the indication, dosage, timing, alternative explanations, and the safety of any modification. Do not independently stop or taper prescribed medication. Drug-induced depression systematic review · NICE NG222
If all my blood tests are normal, is it definitely a mental-health problem?
No. Some physical disorders, including certain sleep, neurological, and post-infectious conditions, require clinical evaluation and investigations beyond routine blood tests. Depressive disorders are also established clinically, not by a blood-test result. The next step depends on symptoms, examination, and impairment. CDC: Long COVID Guidance · NIMH
Can a person have both a medical illness and major depression?
Yes. Chronic physical conditions and depressive disorders can coexist and worsen each other's impact on functioning and care. The correct plan may address both at the same time and use coordinated medical and mental-health follow-up. NIMH: Chronic Disease and Depression · NICE CG91
XV. Clinical Takeaway
The medical evaluation of depression-like symptoms is an evidence-guided search for relevant, actionable explanations. Thyroid disorders, anemia, vitamin B12 deficiency, sleep apnea, metabolic abnormalities, medication effects, neurological disease, and other illnesses are considered according to the person's actual history, symptoms, physical examination, and risks. A physical diagnosis can explain part of a presentation, and it can coexist with a clinically significant depressive disorder. The goal is to identify treatable contributors, recognize risk, and provide appropriate follow-up for the whole person. NICE NG222 · VA/DoD guideline
Related Articles
References
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