Pathogenesis (development of disease)
The pathogenesis of anxiety disorders is not yet clear. It is thought to be multifactorial in origin, with social influences playing a role in addition to genetic ones. Traumatic life experiences, malconditioning, and neurobiologic dysfunction are discussed as possible etiologic factors.
Furthermore, a lowered arousal threshold of the limbic system with involvement of the amygdala and hypothalamus is suspected.
Anxiety disorders can be further divided into a primary anxiety disorder, as well as a form due to physical or mental illness.
The same pathomechanisms apply to generalized anxiety disorder (GAS).
Etiology (causes)
Biographical causes
- Genetic burden from parents, grandparents (proportion of genetic factors in the development of anxiety disorders is about 30% to 65%)
- At least four variants of the gene GLRB (glycine receptor B) are risk factors for anxiety and panic disorders.
- Birth weight < 1,000 grams; a larger sample suggests that there is no persistent increased risk for anxiety disorders in infants born before 32 weeks’ gestation or at less than 1,500 grams
- Disorder-specific developmental history: anxious, shy, passive, new situation-avoiding infants.
- Living alone
Behavioral causes
- Consumption of stimulants
- Coffee, tea (caffeine)*
- Alcohol (woman: > 40 g/day; man: > 60 g/day) [alcohol abuse].
- Drug use
- Amphetamines* e.g. Ectasy (synonym: Molly; MDMA: 3,4-methylenedioxy-N-methylamphetamine) or similarly acting sympathomimetics; metamphetamines (“crystal meth”).
- Cannabis* (hashish and marijuana).
- Hallucinogens*
- Heroin
- Inhalants, i.e. sniffing substances* .
- Cocaine
- Phencyclidine* (e.g. “Angel Dust”)
- Overweight (BMI ≥ 25; obesity).
Disease-related causes
- Diabetes mellitus
- Almost any organic disease can lead to anxiety disorders
- Non-treatable diseases often lead to anxiety disorders
- Many psychiatric illnesses (e.g., depression, eating disorders) lead to anxiety disorders
Medication
- Anticholinergics (aclidinium, biperiden, darifenacin, glycopyrronium, ipratropium bromide, metixene, methanthelinium bromide, oxybutynin, phenoxybenzamine, propiverine, scopolamine, solifenacin, tiotropium, tolterodine, trihexyphenidyl, trospium chloride, umeclidinium).
- Antiepileptic drugs
- AMPA receptor antagonist (perampanel).
- Antiviral drugs (foscarnet).
- Anxiolytics*
- Benzodiazepine antagonist (flumazenil).
- HCV protease inhibitor (boceprevir).
- Hypnotics*
- Sedatives*
- Drug dependence of any kind
Operations
- Condition before or after major surgery
* Substance-induced anxiety disorder.