Depression (Unipolar)

Introduction

• Description: Depression is a biochemically mediated state in which anger, frustration, loss of pleasure, discouragement or hopelessness, and withdrawal predominate. This must be separated from normal stress reactions and grief. The term may be used to describe a mood state, syndrome, or mental disorder.

• Prevalence: Twenty million American adults per year; one in six to eight lifetime risk; 6%–14% of primary care visits; 2:1 female-to-male ratio (1:1 after the age of 55 years). Depression is the fourth most common reason to seek medical care, yet may be missed in more than 50% of cases.

• Predominant Age: Rare before puberty. Commonly begins in 20s–30s.

• Genetics: Possible defect on chromosome 11 or X.

Etiology And Pathogenesis

• Causes: Proposed—alteration in norepinephrine or serotonin through impaired synthesis of neurotransmitters, increased breakdown or metabolism of neurotransmitters, increased uptake of neurotransmitters.

• Risk Factors: Strong family history (depression, suicide, alcoholism, substance abuse). Women are at greatest risk during adolescence (up to 60% meet the criteria), the premenstrual period, pregnancy, the postpartum period, perimenopause, after pregnancy loss (three times increased risk), and with infertility (two times increased risk). Women are especially vulnerable to depression after giving birth.

Signs And Symptoms

• Depressed mood or anhedonia plus five or more other symptoms over a 2-week period:

  • Weight loss

  • Sleep changes

  • Psychomotor changes

  • Fatigue

  • Feeling of worthlessness or guilt

  • Inability to concentrate

  • Thoughts of death

• (Hallucinations and delusions may appear in profound cases.)

Diagnostic Approach