Final answer:
The true statement about diazepam is that it causes amnesia. It is a central nervous system depressant with potential for abuse and dependency, and cannot be obtained without a prescription.
Step-by-step explanation:
The statement that is true about diazepam is that it causes amnesia. Diazepam is a medication classified under benzodiazepines, which are known as central nervous system depressants. When used, diazepam can lead to effects such as anxiolysis, sedation, cognitive and memory impairment, as well as anticonvulsant effects. It does not improve performance of fine motor skills; rather, it can actually impair this ability.
Diazepam is not available without a prescription in Canada, because it is a controlled substance due to the potential for abuse and dependence. Lastly, diazepam can produce a dependence syndrome, hence it needs to be managed carefully to avoid withdrawal and rebound symptoms.