Selected causes of acute insomnia (< 30 days)*
Situational stress (e.g., occupational, interpersonal, financial, academic, medical)
Environmental stressors (e.g., noise)
Death or illness of a loved one
Selected causes of chronic insomnia (≥ 30 days)
Medical disorders
	Arthropathies, cancer, chronic pain, congestive heart failure, COPD, end-stage renal disease, gastroesophageal reflux disease, HIV/AIDS, hyperthyroidism, nocturia caused by prostatic hypertrophy, stroke
Medications
	Anticholinergic agents; antidepressants (SSRIs, bupropion [Wellbutrin]), MAOIs; antiepileptics (lamotrigine [Lamictal], phenytoin [Dilantin]); antineoplastics; beta blockers; bronchodilators (beta agonists); CNS stimulants (methylphenidate [Ritalin], dextroamphetamine [Dextrostat], nicotine [Nicotrol]); interferon alfa; miscellaneous (diuretics, atorvastatin [Lipitor], levodopa, quinidine); steroids, oral contraceptives, progesterone, thyroid hormone
Primary sleep disorder
	Periodic limb movement disorder, restless legs syndrome, sleep apnea
Psychiatric disorders
	Anxiety disorders, bipolar disorder or schizophrenia, major depressive or dysthymic disorders, personality disorders, post-traumatic stress disorder
Sleep–wake schedule disorder
	Irregular sleep–wake cycle, jet lag, shift work
Substance abuse
	Alcohol, caffeine, drug withdrawal, stimulants (e.g., amphetamines, methamphetamines)