Prevalence
20% of US adults, 15% of children/adolescents.
More common in girls by mid-adolescence.
Symptoms
Trouble sleeping, feelings of guilt, fatigue.
Losing interest in enjoyable activities, suicidal thoughts.
Subjective Experience
Varies by disorder; anxiety: worry, panic; depression: sadness, hopelessness.
Etiology
Biological, psychological, and social causes.
Treatment
Cognitive therapy/medicine most effective.
Other methods: meditation, support groups, light therapy.