Whether 6 months is "long" or "short" depends on what kind of medications you are talking about and what condition you are trying to treat. For depression, I have heard that once a person goes on an anti-depressant and it is helping them, that they should stay on it for at least a year to stabilize. That is just something I heard...

For other types of drugs, the answer might be shorter. For example, if you need a sleeping aid, it might only be for a week or two. Or if you need anti-anxiety medication, it might only be until very stressful events in your life have calmed down.

For other types of drugs, it might be a lifetime of use that would be optimal. Like for schizophrenia, one might need to take a med regularly for years to contain psychotic symptoms.

There are also non-medication alternatives to managing some conditions. For example, some people use psychotherapy for depression with good success. Some people use meditation for anxiety. Some people use behavioral therapy for ADHD. Etc.