About 10 per cent of people with bipolar take their lives.

In Australia, about 10 per cent of bipolar sufferers make one suicide attempt every year.

And about half of bipolar sufferers do not take or do not regularly take their medication*.

So when Melissa Joy Dietzel, a 22-year-old US nanny whose mother's family had a history of bipolar disorder and suicides killed herself in Sydney recently, it was a sad end to a young life that was full of promise.

But Professor Philip Mitchell, the Head of the School of Psychiatry at the University of New South Wales, said while statistics showed how lethal the condition was, he was optimistic that treatment - through medication and cognitive behavioural therapy - could help bipolar sufferers manage the illness.

In Australia, the lifetime prevalence of bipolar in the population is about 1.3 per cent, according to the 2007 Australian Bureau of Statistics' National Survey of Mental Health and Wellbeing report. In the United States, a 2005 study puts the risk of bipolar as between 3 to 10 per cent.

Diagnosis

"I'd never heard the word before, but for the first time, at the age of 37, I had a diagnosis that explains the massive highs and miserable lows I've lived with all my life," - British comedian Stephen Fry on his bipolar diagnosis.

The first step towards treating bipolar is correct diagnosis, Professor Mitchell, who is also the director of the bipolar disorder clinic at the Black Dog Institute, said.

Bipolar is a disorder characterised by mood swings, from excessive highs to excessive lows. Bipolar I, where a person has episodes of mania - sometimes with psychotic features - and episodes of depression, is most likely to develop between the ages of 18 to 29.

Symptoms of the condition include:

- depression

- not needing as much sleep

- becoming more active than normal

- becoming more talkative, spending more or being more generous

In Australia, only one-third of bipolar sufferers receive treatment, 69 per cent of people with bipolar are mis-diagnosed 3.5 times, and on average, it takes about a decade and four doctors to obtain a correct diagnosis of bipolar, according to a 2003 study.

"In general terms, it's critical that when a doctor sees someone with depression to enquire as to whether they've had any manic episodes in the past or there can be a less severe form, which we call hypomania, where it's the same experience but not as severe," Professor Mitchell said.

"Sometimes what you find when you ask someone is that they've had periods [of mania] in their lives, but it's never been diagnosed."

Treatment

"It is as if my life were magically run by two electric currents: joyous positive and despairing negative - which ever is running at the moment dominates my life, floods it. I am now flooded with despair, almost hysteria, as if I were smothering. As if a great muscular owl were sitting on my chest, its talons clenching & constricting my heart." - writer Sylvia Plath, who killed herself at 30 and was believed to have suffered from bipolar disorder

Bipolar is managed using mood stabilisers such as lithium, which reduces a person's chance of slipping into mania or depression, and focused psychological treatment, Professor Mitchell said.

Psychological treatment, such as cognitive behavioural therapy, has been seen in recent years as an important complement to medication, by helping patients deal with triggers to episodes and how they understand and make sense of the illness, he said.

But getting people to take their medication was difficult.

"It's a big problem," Professor Mitchell said, pointing out that about half of people with bipolar did not take their medication regularly, or did not take them at all.

"During manic episodes, people lose their awareness and they think they are fine. ... The patient doesn't think that they need treatment, so they get annoyed when the family says 'you should go and see the doctor' and often at that stage, they will stop taking medication.

"But even when they are not high ... one of the main issues when treating someone with bipolar is the acceptance of the need for continuing to take the treatment."

That's when the family and friends of the person with bipolar come in, he said.

They need to encourage their loved one to seek medication help for their condition, if they haven't yet, but also persuade them to see their doctor or take their medication if they have stopped.

And if their loved one continued to refuse taking their medication - and started to become more disturbed or exhibit psychotic behaviour such experience delusions or hallucinations - they should bring them to their local community mental health centre to get immediate medical attention, Professor Mitchell said.

But with regular treatment and therapy, people with bipolar were often able to manage their condition and continuing their studies, work and family lives, he added.

Renowned bipolar sufferers include British comedian Stephen Fry, former NRL player Andrew Johns, US actors Richard Dreyfuss, Carrie Fisher, British actress Catherine Zeta Jones and British singer Adam Ant and the late Australian newsreader Charmaine Dragun.

* Support is available for anyone who may be distressed by calling Lifeline 131 114, Mensline 1300 789 978, Kids Helpline 1800 551 800, Black Dog Institute 1800 352 292

Further reading:Bipolar self-test (Black Dog Institute)Facts and figures about mental health and mood disordersBipolar treatment guide (Federal Department of Health and Ageing)Stephen Fry: The Secret Life of the Manic Depressive - documentary by the British comedian about his battle with bipolar

*Hereditary bipolar: According to Professor Philip Mitchell, the Head of the School of Psychiatry at the University of New South Wales, and Dr Candida Fink, psychiatrist and author of The Ups and Downs of Raising a Bipolar Child.

Bipolar and suicide: According to Professor Philip Mitchell. Further reading about the data from the World Federation for Mental Health.

Attempted suicide and bipolar: According to the Australian Bureau of Statistics, via the Black Dog Institute.

Treatment non-compliance and bipolar: According to Professor Philip Mitchell. Further details from the Journal of Clinical Psychiatry via the US National Library of Medicine