Brain and nervous system disorders

Brain tumors

Dementia (in early stages)

Head injury

Multiple sclerosis

Parkinson disease

Sleep apnea

Stroke

Seizures that affect the temporal lobe (focal seizures)

Cancers

Cancer spreading throughout the body (metastatic)

Cancer of the pancreas

Connective tissue disorders

Systemic lupus erythematosus (lupus)

Hormonal disorders

Addison disease

Cushing syndrome

Diabetes mellitus

hyperparathyroidism)

Low or high levels of thyroid hormone (hypothyroidism or hyperthyroidism)

Low levels of pituitary hormones (hypopituitarism)

Low levels of testosterone (hypogonadism)

Infections

AIDS

Influenza

Mononucleosis

Syphilis (late stage)

Tuberculosis

Viral hepatitis

Viral pneumonia

Mental health disorders other than mood disorders

Antisocial personality disorder

Anxiety disorders

Borderline personality disorder

Dementia in the early stages

Schizophrenia

Substance use disorders

Nutritional disorders

Pellagra (vitamin B6 deficiency)

Pernicious anemia (a form of vitamin B12 deficiency)

Other disorders

Coronary artery disease

Fibromyalgia

Kidney failure

Liver failure

Medications, substances, and illicit drugs

Alcohol

Antipsychotic medications

Beta-blockers (some)

Contraceptives (oral)

Corticosteroids

Hormone (estrogen

Interferon

Mercury

Reserpine

Thallium