Subjects

THC dose

Schizophrenic symptoms

Study

Normal volunteers

Δ⁹-THC (0.5 mg/kg, orally)

Depersonalization, disconnected thoughts, paranoid ideas.

[13]

Healthy cannabis users

Δ⁹-THC (2.5, and 5 mg, i.v.)

Positive symptoms: Suspiciousness, paranoid and grandiose delusions.

Negative symptoms: Psychomotor retardation, and emotional withdrawal.

[10]

Subjects with paranoid ideation

Δ⁹-THC (1.5 mg, i.v.)

­ Paranoia

Worry, anxiety, depression, and negative thoughts about the self.

[51]

Healthy subjects who were recent users of cannabis

Δ⁹-THC milk decoction (16.5 mg) or synthetic Δ⁹-THC (dronabinol; 20 mg/kg) orally.

Depersonalization, paranoid feelings, derealization and irrational anxiety.

[52]

Healthy subjects who were cannabis users

Δ⁹-THC (10 mg, orally)

­ Psychotic symptoms

­ Levels of anxiety 

[53].

Cannabis users

Δ⁹-THC 8 mg or Δ⁹-THC 8 mg + CBD 16 mg (by inhalation through a vaporizer).

­ BPRS negative symptoms

­ Perceptual distortions and cognitive disorganization

[57]