Can certain diseases cause paranoia similar to that seen in...

Brain Tumors

Grief (yes, sadly)

PTSD

Stress

Delirium tremens

Mental disorder

Infection

Withdrawal from benzodiazepines

Dementia with Lewy bodies

Head injury

Alcohol

Hallucinogen use

Pharmaceutical drug (abuse or side effects)

Dementia and drug use cause paranoia. That is very common. Some of other things that can include delusions and/or hallucination can be:

Narcolepsy

Charles Bonnet syndrome

Fever

Migraines

⁉️sources from my experiences and internet research ⁉️

Some of those things on the list are very very rare cases but I just wanted to cover everything (or almost everything).

Parkinson's disease

Sleep disorders

Affective disorders

Bipolar disorder

Alzheimer's disease,

Seizures

Alcohol withdrawal

Can certain diseases cause paranoia similar to that seen in individuals with paranoid schizophrenia, even if they do not have the disorder?