a sleep study (the nighttime polysomnograph plus the multiple sleep latency test the next day) will test for any & all sleep disorders, not just one. they may only be wanting to rule out one thing based on your answers to his questions – narcolepsy – but it will bring to light any causes for the issues you may be having, apnea included.

if occasional hallucinations are the only symptom you have, then i’d say no, it’s not worth it at this time. there really aren’t any treatments – or even lifestyle modifications – that can be done for them. it’s just a matter of recognizing them when going thru them & letting it ride thru or waking up to dispel it.

if however, you are experiencing any of the other symptoms of narcolepsy…and i’d be awfully surprised if you end up with a positive diagnosis of narcolepsy, and hallucinations are the only one you have…them i’d say from a personal standpoint, yes, it’s worth it. while there is no cure for narcolepsy, there are various medications which can help make life much more bearable for someone with this. not to mention, narcolepsy is covered under the disability act, which means your job status may be safe if it ever interferes with your employment. also, having a positive diagnosis of narco wouldn’t immediately preclude you from doing things like driving. that only happens if it is uncontrolled & you are a danger to those around you.

you don’t mention your age, but keep in mind that with narcolepsy, it generally starts with one symptom and others develop over time. they usually grow in severity until we’re in our 30s-40s, at which time they level off & stay at about that severity from then on. so if you are young, you may end up developing further symptoms as time goes on that might need medical help to deal with. if however, you are already middle aged, and haven’t experienced any other symptoms besides hallucinations, you probably won’t develop others later.