People struggling with depression could also have problems with sleep, Dr McGrath said.
"That can mean problems getting off to sleep and waking early and not being able to get back to sleep [or] waking in the middle of the night and finding they toss and turn and can't sleep."
Nationally, nearly 680,000 sleeping pill prescriptions were doled out in the financial year.
People who use sleeping pills for extended periods of time risk becoming addicted, Dr McGrath warned.
"When they first came out in the 1950s and 1960s, I don't think that was realised and doctors prescribed them for months at a time or even years and that got people physically dependent on those drugs."
Doctors were a lot more careful now, he said.
"People often take them [sleep medication] every second or third night and then stop them eventually or cut their dose down."
Tranx - an alcohol and drug addiction service which deals specifically with sleeping-medication dependency - says New Zealand's high prescription numbers are concerning.
Whilst Pharmac figures show prescription numbers are similar to those five years ago (680,950 in 2007/08), data recording methods and restrictions around prescribing medication have since changed - masking the actual increase.
Tranx manager Shaz Picard said long-term use of sleeping pills was risky.
"If somebody's using it on a daily basis there's more chance of them becoming addicted.
"We learn how to sleep, and if you're taking a drug that gives you a black-out, knock-out, zonk-of-a-sleep then after six months or so your body doesn't know how to go to sleep."
However, if sleep medication was used appropriately, it could provide a relief for those suffering insomnia, stress or grief, Ms Picard said.
"Anybody knows if you don't get any sleep, you can become quite psychotic after a while because humans have to sleep.
"But, what happens is people get on the gravy train and they're still taking them [long after the event]."
Pharmac medical director Dr Peter Moodie said a steady increase in prescription figures, for all medications including sleeping tablets, was expected each year due to population growth and greater access to health care.
"There has been a growth and it's a growth that we watch and we haven't had alarm bells ringing," he said.