Which medication is used primarily as an anti-anxiety medication?

Lorazepam is primarily used as an anti-anxiety medication and belongs to the benzodiazepine class of drugs. It acts on the central nervous system to produce a calming effect, making it effective for reducing anxiety symptoms. Benzodiazepines like Lorazepam enhance the effect of the neurotransmitter GABA (gamma-aminobutyric acid) in the brain, which helps to alleviate feelings of nervousness or fear.

The other medications listed serve different primary purposes. Olanzapine is an atypical antipsychotic used mainly for managing conditions such as schizophrenia and bipolar disorder. Sertraline is a selective serotonin reuptake inhibitor (SSRI) typically prescribed for depression and certain anxiety disorders but is not classified solely as an anti-anxiety medication. Haloperidol is a typical antipsychotic used to treat serious mental health conditions and is not indicated for anxiety. Thus, Lorazepam stands out as the primary anti-anxiety medication among the options provided.