Paranoia

An intense, irrational, and persistent belief that others are trying to harm, deceive, persecute, or conspire against an individual, usually occurring without prominent hallucinations or severe disorganization of thought.

Causes

• Psychiatric causes

  • Schizophrenia

  • Bipolar disorder (during manic or depressive episodes with psychotic features)

  • Anxiety disorders

  • Post-traumatic stress disorder (PTSD)

  • Social isolation and loneliness

  • Delusional disorder

• Medications and substances causing psychosis

  • Cocaine use

  • Cannabis use

  • Amphetamine use

  • Alcohol abuse or withdrawal

• Neurological causes

  • Alzheimer’s disease

  • Parkinson’s disease

  • Dementia with Lewy bodies

  • Other neurodegenerative disorders

  • Brain tumors or structural brain lesions

  • Stroke affecting relevant brain regions

• Physiological and environmental causes

  • Sleep deprivation

  • Chronic stress

  • Severe emotional trauma

  • Social deprivation

• Age-related causes

  • Sensory decline (reduced vision or hearing)

  • Cognitive decline associated with aging

• Delirium due to infection, metabolic disturbance, or systemic illness