Description

• Persistent, excessive, and difficult-to-control worry associated with significant symptoms of motor tension, autonomic hyperactivity, and/or disturbances of sleep or concentration
• System(s) affected: Nervous (resulting in increased sympathetic tone and increased catecholamine release)

Epidemiology

• 12-month prevalence rate: 3.1%
• Lifetime prevalence rate: 5.7%
• Onset can occur any time in life, from adolescence to adulthood; median age of onset in US is 31 years.
• Predominant sex: Female > Male (2:1)
• Anxiety accounts for 5–8% of primary care office visits.

Risk Factors

• Caucasian race
• Adverse life events: Stress, medical illness, disability, unemployment, childhood physical and mental abuse
• Family history
• Lack of social support
• Depression
• Lesbian/Bisexual women at increased risk

• Strongly linked to depression in heritability studies
• A variant of the serotonin transporter gene (5HT1A) may contribute to both conditions; other genes (such as that for glutamic acid decarboxylase) also may play a role.

General Prevention

Regular exercise is associated with decreased anxiety and depression.

Pathophysiology

fMRI studies display decreased amygdala connectivity bilaterally.

Etiology

Mediated by abnormalities of neurotransmitter systems (i.e., serotonin, norepinephrine, and γ-aminobutyric acid [GABA])

Commonly Associated Conditions

• Major depressive disorder (>60%), dysthymia, bipolar disorder
• Alcohol/Drug abuse (37.6%/27.6%)
• Cigarette smoking in adolescence
• Panic disorder, agoraphobia, simple phobia, social anxiety disorder, anorexia nervosa