For Patients & General Readers
Major Depressive Disorder (MDD) is a common but serious mood disorder that causes persistent feelings of sadness and loss of interest. It can affect how you feel, think, and behave and can lead to a variety of emotional and physical problems. MDD can significantly impact your ability to function at work, school, and in social settings, and can even be life-threatening if left untreated.
Clinical Overview
Major Depressive Disorder (MDD) is a mood disorder characterized by at least two weeks of persistent depressed mood or anhedonia, accompanied by other cognitive, behavioral, and somatic symptoms that cause significant functional impairment. Diagnosis is primarily clinical, based on DSM-5-TR criteria, and requires ruling out other medical and psychiatric conditions.
Clinical Presentation
- Persistent depressed mood for most of the day, nearly every day.
- Markedly diminished interest or pleasure in all, or almost all, activities.
- Significant weight loss or gain, or decrease or increase in appetite.
- Insomnia or hypersomnia nearly every day.
- Psychomotor agitation or retardation observable by others.
- Fatigue or loss of energy nearly every day.
- Feelings of worthlessness or excessive or inappropriate guilt.
- Diminished ability to think or concentrate, or indecisiveness.
- Recurrent thoughts of death, suicidal ideation without a specific plan, or a suicide attempt or a specific plan for committing suicide.
Signs & Symptoms
Symptoms (Patient-Reported)
- Feeling sad, empty, or hopeless
- Loss of interest in activities I used to enjoy
- Changes in appetite or weight
- Difficulty sleeping or sleeping too much
- Feeling tired or having no energy
- Feeling worthless or guilty
- Trouble concentrating or making decisions
- Thoughts of death or suicide
Signs (Clinician-Observed)
- Depressed affect (e.g., tearfulness, flat affect)
- Slowed speech and thought processes
- Poor hygiene and self-care
- Social withdrawal
- Psychomotor retardation or agitation
Differential Diagnoses
| Condition | Distinguishing Feature |
|---|
| Bipolar Disorder (Depressive Episode) | History of manic or hypomanic episodes. |
| Persistent Depressive Disorder (Dysthymia) | Depressed mood for at least two years, with less severe but chronic symptoms. |
| Substance/Medication-Induced Depressive Disorder | Depressive symptoms coincide with intoxication or withdrawal from a substance or medication. |
| Depressive Disorder Due to Another Medical Condition | Depressive symptoms are a direct physiological consequence of a general medical condition (e.g., hypothyroidism, neurological disorders). |
| Adjustment Disorder with Depressed Mood | Depressive symptoms develop in response to an identifiable stressor and do not meet full criteria for MDD. |
| Grief/Bereavement | Depressed mood is predominantly related to the loss of a loved one and typically improves over time, though it can be complicated. |
Red Flags — Seek Immediate Care
- Active suicidal ideation with intent and a plan
- Command hallucinations instructing self-harm
- Severe functional impairment leading to immediate risk (e.g., inability to care for basic needs)
- Acute psychotic features (e.g., delusions, hallucinations) in the context of depression
Key Investigations
- Comprehensive psychiatric history and mental status examination
- Screening for substance use disorders
- Thyroid function tests (TSH, free T4) to rule out hypothyroidism
- Complete blood count (CBC) to rule out anemia
- Vitamin B12 and folate levels
- Urine drug screen
- Electrocardiogram (ECG) if considering certain medications or cardiac concerns
Management Overview
Management of MDD is multimodal, typically involving pharmacotherapy (e.g., SSRIs, SNRIs, TCAs, atypicals) and psychotherapy (e.g., CBT, IPT). For severe or treatment-resistant depression, augmentation strategies, neuromodulation (e.g., ECT, TMS), or combination therapies may be considered. Close monitoring for treatment response, side effects, and suicidal ideation is crucial.
Disclaimer: This article is for educational purposes only and does not constitute medical advice.
Always consult a qualified healthcare professional for diagnosis and treatment.
TruelyserMD does not replace clinical judgement.