Better Health Victoria states that a chronic illness means having to adjust to the demands of the illness and the therapy used to treat the condition.

There may be additional stresses, since chronic illness might change the way you live, see yourself and relate to others.

In an article published by the Robert Wood Johnson Foundation in January 2010 written by Dr Gary Anderson on chronic care, 145 million people, that is almost half of all Americans, were living with a chronic condition while 26 per cent aged 18 years and older suffered from a diagnosable mental disorder.

Arthritis, as a chronic condition, and depression, as a mental health illness, are leading causes of disability worldwide.

Other US research conducted by Drs Chapman, Perry and Strine found that associations exist between mental illness and cardiovascular disease, diabetes, obesity, asthma and arthritis.

For example, depression was found to co-occur in 17 per cent of cardiovascular cases, 23 per cent of cerebrovascular cases, 27 per cent of diabetes patients and in more than 40 per cent of individuals with cancer with the latter being confirmed by the American Heart Association.

The American Epilepsy Society sights many examples that exist of individuals with a chronic condition and an increased risk for mental illness such as the risk for tobacco use, which is about twice as high for those with mental illness compared to the general population.

Beyond Blue, through their website, states that it can be difficult to know whether you are feeling down because of your physical health or if you do actually have symptoms of depression or anxiety.

A sudden or unexpected health event, such as a heart attack, stroke, diagnosis of cancer, or other serious illness or injury may cause you to have feelings of shock, anger, grief, loss and sadness.

Although these feelings usually pass with time, they can cause ongoing stress, which could lead to a greater risk of you developing depression or anxiety.

In the Medical Journal of Australia (MJA), a study conducted by David Clarke and Kay Currie 2009, looked at the effects of depression and anxiety and their relationship with chronic diseases.

Some of their findings indicated that in any year, nearly 18 per cent of Australians have depression or anxiety and 43 per cent of these people have a physical illness.

Women with heart disease tended to report more symptoms of depression and anxiety than men while in people with cancer the prevalence of depression was estimated to be up to four times that of the general population.

Further, depression was diagnosed in hospitalised patients with various cardiac complications, while 60-70 per cent of patients were still depressed at one to four months whereas post-stroke depression rates were significantly high at 40 per cent beyond six months.

However, the National Institute of Mental Health points out that there are some risk factors directly related to having another illness.

For example, conditions such as Parkinson's disease and stroke cause changes in the brain.

In some cases, these changes may have a direct role in depression.

Sometimes certain medications used to treat the illness may trigger depression.

Depression may persist, even as a person's physical health improves.

A person should not dismiss depression as simply a normal part of having a chronic illness.

There are effective treatments for depression and can help even if you have another medical illness or condition.

Lifeline Australia suggests that it is important to surround yourself with positive and supportive people.

Try to find small things that you can enjoy every day, and set realistic short-term goals for yourself.

Even small goals such as a visit to a park or museum, or a phone call with a close friend can help you make the most of each day.

Chronic illness may be challenging but the effects of a well-supported program or therapist can provide at times welcomed mental health relief.

If you or someone you know is suffering from a chronic illness and is also struggling with their mental health contact your local GP, Mental Health Foundation of Australia (03) 9826 1422, Lifeline 131114 or ReachOut.com.

Dr Anthony Perrone is college counsellor at Trinity Anglican College. The views expressed in this column are Dr Perrone's and not necessarily those of Trinity Anglican College.