Despite recent advances in the understanding and treatment of schizophrenia, this devastating disease still affects one percent of world's population. Existing antipsychotics reduce psychotic symptoms but are generally not very effective in treating so called negative symptoms such as blunted affect and social withdrawal or cognitive disturbances due to the disease. Furthermore, a significant portion of patients is refractory to all current treatments. Therefore new treatment strategies are needed.

Several studies suggest a strong association between schizophrenia and the endocannabinoid system. This system mediates e.g. the pro-psychotic effects of the best-known ingredient of the cannabis plant - delta-tetrahydrocannabinol (Δ9-THC). While the pro-psychotic Δ9-THC is known to abet the onset of schizophrenia, another, non-psychotomimetic plant ingredient - cannabidiol - has recently been shown to exert antipsychotic effects similar to those of one of the most effective modern antipsychotics, amisulpride, but it induced significantly less side effects.

In this phase I safety study, the investigators will evaluate the pharmacokinetics, pharmacoequivalence, and drug-drug interaction profile with current antipsychotics of a new tablet pharmaceutical preparation of cannabidiol in healthy volunteers.

Inclusion Criteria:

• Informed consent given by the subject
• Both, female and male subjects may participate
• Age between 18 and 45
• Negative drug screening at the time of screening
• Non-smoking
• In female participants in fertile age, reliable contraception, which means contraception's pearl-index is equal or smaller than 1.
• Body Mass Index between 18 and 30

Exclusion Criteria:

• Lack of accountability
• Any current psychiatric disorder through the Structured Clinical Interview for DSM-IV (SCID) at the time of screening
• Pregnancy or lactation phase in female at the time of screening
• Any known psychiatric or neurological illness in the participant's history.
• Known family history concerning psychiatric disorders
• Relevant use of cannabis (which is defined on the present state of knowledge as at the most five times lifetime-consumption and no consumption for at least one year)
• Severe physical (internal) or neurological illness, especially cardiovascular, renal, advanced respiratory, haematological or endocrinological failures or infectious diseases (acute hepatitis A, B or C or HIV) assessed at the time of the screening by the subject's history, clinical examination and laboratory testing, at the discretion of the investigator
• Consumption of any illicit drugs (except cannabis in history, see above)