Clinical depression is a psychiatric disorder characterized by pervasive and persistent low mood, resulting in low self-esteem, anhedonia (loss of interest of pleasure), and pleasure.

• Combination of hereditary and psychosocial factors
• Also linked w/ substance abuse
• Causes decreased levels of monoamines (esp serotonin, norepinephrine and dopamine), which are required for communication between neurons

• Endogenous depression, is Tx-resistant, non-psychotic, clinical depression, involving abnormal behavior of the endogenous opioid system, but NOT the monoaminergic system

• It is a disabling condition, affecting the Pt's:
  • Family
  • Work/school
  • Sleeping/eating habits
  • General health

• The Dx is based on the patient’s self-reported experiences, behavior reported by relatives or friends, and a mental status examination
• There is no lab test for major depression, although doctors generally request tests for physical conditions that may cause similar Sx
• This is not the same as description by the Pt of being depressed, which is advising of an internal state of low mood and loss of interest in activity
• It can be a normal reaction to certain life events, or a side effect of certain drugs

• Psychotherapy/counseling, and antidepressant medication, although its effectiveness is questionable for mild to moderate cases (and may also be linked w/ suicide risk). For those of significant risk of harm to self or others, hospitalization and even ECT may be required

• 3.4% of Pt's will commit suicide
• Up to 60% of people who die by suicide had depression or another mood disorder
• Pt's have shorter life expectancy due to greater susceptibility to illnesses and suicide

• The most common time of onset is between 20-30yo, with a later peak between 30-40yo

• Bipolar disorder
• Major depressive episode