What are the symptoms and treatment options for depression in adults?

Symptoms of Depression in Adults

Depression is characterized by depressed mood or loss of interest/pleasure (anhedonia) along with at least 5 total symptoms lasting at least 2 weeks that impair normal functioning. 1

Core Diagnostic Symptoms

The two cardinal symptoms that define depression are:

• Depressed mood - feeling down, sad, or hopeless most of the day, nearly every day 2, 1
• Anhedonia - markedly diminished interest or pleasure in activities that were previously enjoyable 2, 1

At least one of these two core symptoms must be present for diagnosis. 1

Additional Diagnostic Symptoms

To meet diagnostic criteria, at least 5 total symptoms (including one of the core symptoms above) must be present during the same 2-week period:

• Sleep disturbances - insomnia or hypersomnia nearly every day 2, 1
• Fatigue or loss of energy - persistent tiredness even without exertion 2, 1
• Appetite changes - significant weight loss/gain or changes in appetite 2
• Low self-view - feelings of worthlessness or excessive/inappropriate guilt 2
• Concentration difficulties - diminished ability to think, concentrate, or make decisions 2
• Psychomotor changes - agitation or retardation observable by others 2, 1
• Thoughts of self-harm - recurrent thoughts of death or suicidal ideation 2

Severity Assessment

Depression severity is classified based on symptom count, intensity, and functional impairment:

• Mild depression: PHQ-9 score 5-9 or minimal functional impairment 2, 1
• Moderate depression: PHQ-9 score 10-14 or moderate functional impairment 2, 1
• Severe depression: PHQ-9 score 15-27 or marked functional impairment 2, 1

Screening Tools

The PHQ-9 is the recommended validated screening tool, starting with the 2-item version asking about depressed mood and anhedonia. 2, 1

• If the 2-item PHQ score is 0-1, no further screening is needed 2
• If the 2-item PHQ score is 2-3, complete the full 9-item questionnaire 2
• Alternative validated tools include the Hamilton Depression Rating Scale (HAM-D) and Hospital Anxiety and Depression Scale (HADS) 2

Critical Red Flags Requiring Emergency Evaluation

Any patient expressing suicidal ideation or risk of harm to self/others requires immediate referral for emergency psychiatric evaluation. 2, 3

• Suicidal thinking and behavior risk is highest in the first few months of antidepressant treatment, particularly in patients under age 24 3
• Emergence of agitation, panic attacks, severe insomnia, irritability, hostility, or impulsivity may represent precursors to suicidality 3

Common Comorbidities to Assess

• Anxiety disorders: 50-60% of patients with depression have comorbid anxiety, most commonly generalized anxiety disorder 2
• Substance use disorders: Common in untreated depression and worsen prognosis 1
• Bipolar disorder screening: Essential before initiating antidepressants, as treating unrecognized bipolar depression with antidepressants alone may precipitate manic episodes 3

Treatment Options

First-Line Treatments

Either cognitive behavioral therapy (CBT) or second-generation antidepressants (SSRIs/SNRIs) are equally effective first-line treatments for moderate depression. 1, 4

• For mild depression, start with CBT alone 1
• For moderate to severe depression, initiate either CBT or antidepressants based on patient preference, cost, and side effect concerns 1
• For severe depression, combination therapy (CBT + antidepressant) is superior to monotherapy, nearly doubling remission rates (57.5% vs 31.0%) 1, 4

Pharmacotherapy Specifics

• SSRIs (fluoxetine, escitalopram, citalopram) or SNRIs (venlafaxine, duloxetine) are first-line medications 1
• SNRIs are slightly more effective than SSRIs but have higher rates of nausea and vomiting 1
• Selection should be based on adverse effect profiles, drug interactions, prior treatment response, and patient preference 2
• Therapeutic effects typically require 4-6 weeks at adequate doses 1

Psychotherapy Options

Effective psychotherapy modalities include:

• Cognitive behavioral therapy (CBT) 1, 4
• Behavioral activation 4
• Interpersonal therapy (IPT) 4
• Problem-solving therapy 4
• Brief psychodynamic therapy 4

Treatment Duration

• Continue treatment for at least 4-9 months after satisfactory response for first episodes 1
• For recurrent depression, continue treatment for ≥1 year or longer 1
• Premature discontinuation is a common pitfall leading to relapse 1

Monitoring and Follow-Up

• Assess treatment response within 1-2 weeks of initiation, monitoring for therapeutic effects, adverse effects, and suicidality 1
• If inadequate response by 6-8 weeks, modify treatment through dose adjustment, medication switching, or augmentation strategies 1
• Close monitoring significantly improves treatment success, with collaborative care programs showing substantial symptom improvement (SMD 0.42) compared to usual care 4

Special Considerations

Medical Causes

Always first treat underlying medical causes of depressive symptoms (unrelieved pain, fatigue) and delirium (infection, electrolyte imbalance) before attributing symptoms to primary depression. 2, 5

Marital/Relationship Issues

When depression occurs with significant marital distress, behavioral couples therapy should be added to individual CBT 6

Treatment-Resistant Depression

• Defined as failure to respond to two or more adequate antidepressant trials (sufficient dose and duration, minimum 4 weeks) 1
• Second-line options include switching antidepressants, adding a second antidepressant, or augmenting with non-antidepressant medications 4