Low mood/affective problems

• Major depressive disorder: Persistent low mood, anhedonia, fatigue, and cognitive impairments; may include suicidal ideation.
• Bipolar disorder: Episodes of both depression and mania/hypomania; key features include mood swings, changes in energy levels, and behavior.
• Dysthymia (Persistent depressive disorder): Chronic low-grade depression lasting at least two years, with fewer and milder symptoms than major depression.

• Generalized anxiety disorder (GAD): Chronic and excessive worry about various aspects of life; often associated with physical symptoms such as tension, sleep disturbances, and fatigue.
• Panic disorder: Recurrent unexpected panic attacks, with ongoing fear of further attacks; symptoms include palpitations, sweating, and chest pain.
• Social anxiety disorder: Intense fear of social situations due to concerns of embarrassment or humiliation; often leads to avoidance behavior.

• Alcohol-related mood disorder: Depression or anxiety related to alcohol use; can be due to intoxication, withdrawal, or chronic alcohol abuse.
• Drug-induced mood disorder: Depression or anxiety caused by recreational or prescription drugs (e.g., corticosteroids, beta-blockers); symptoms often resolve after discontinuation.
• Caffeine or stimulant use: Can cause anxiety, agitation, and mood instability, especially in high doses or withdrawal.

• Hypothyroidism: Often presents with low mood, fatigue, and cognitive slowing; diagnosed via thyroid function tests.
• Cushing’s syndrome: Chronic exposure to high cortisol levels can cause depression, weight gain, and sleep disturbances; physical signs include central obesity and facial rounding.
• Parkinson’s disease: Mood disturbances, particularly depression, are common in Parkinson’s and may precede motor symptoms.

Acute onset of low mood may suggest a reaction to life events or substance use, whereas a gradual onset may indicate a primary mood disorder or chronic medical condition.

Insomnia, early morning wakening, or hypersomnia can be indicative of depressive disorders, while disturbances in sleep cycles may suggest bipolar disorder.

Weight loss and reduced appetite are common in major depression, whereas increased appetite and weight gain may be seen in atypical depression or as part of bipolar disorder.

• Poor concentration: Suggestive of major depressive disorder or anxiety.
• Memory impairment: Common in depression, but also seen in neurodegenerative conditions.
• Indecisiveness: Often a feature of depression and anxiety disorders.

• Past medical history: Important to identify previous episodes of mood disorders, chronic illnesses, or neurological conditions.
• Drug history: Includes antidepressants, mood stabilizers, and any medications that can cause mood changes.
• Family history: Look for a history of mood disorders, particularly in first-degree relatives, as well as any history of suicide.
• Social history: Consider recent life events, occupational stress, and substance use, which may contribute to mood disturbances.

• Full blood count: To rule out anemia or infection contributing to fatigue and low mood.
• Thyroid function tests: To assess for hypothyroidism as a reversible cause of low mood.
• Urea and electrolytes: To assess renal function, which may be relevant in patients on mood stabilizers.
• Liver function tests: Important if considering alcohol-related mood disorders or in patients on long-term psychotropic medication.
• Cortisol levels: To screen for Cushing’s syndrome in patients with suggestive symptoms.

• Brain imaging (CT/MRI): Indicated if there are focal neurological signs, or if organic brain disease is suspected.
• Dexamethasone suppression test: To help diagnose Cushing’s syndrome in the context of depressive symptoms and physical signs.
• Electrocardiogram (ECG): Important in patients on antidepressants or antipsychotics that may prolong the QT interval.