Colours and Sizes of the Black Dog

Wednesday 22 September, 2010

If you or a family member has clinical depression you need to be very careful who you consult, according to one of Australia’s leading psychiatrists, the head of Sydney’s Black Dog Institute at the Prince of Wales Hospital, Professor Gordon Parker.

Delivering the 2010 Warrane Lecture on September 15, Professor Parker expressed concern about existing medical guidelines for the diagnosis of “clinical depression”. He said there was not enough differentiation between different classes of depression. This was partly because the existing guidelines in the Diagnostic and Statistical Manual (DSM) of Mental Disorders, published by the American Psychiatric Association, failed to address the range of causes for the different types of depression.

He said that anyone with depression needed to find a medical practitioner who was “more than merely a meandering warm therapist”.

“I see so many patients who say they have been talking to their psychiatrist or their psychologist who is a ‘lovely human being’. And I will say, ’you have been seeing this person for a while – 5 years – and how often do you see them? Oh, once a week. What’s the game plan? Oh, you haven’t got around to it yet.'

“And that is as dangerous as having a venal exploitative therapist if you are just getting meandering good feeling, but with no substantive component. And that is actually quite common.”

Professor Parker pointed out that there was a lot of concern today about clinical depression, particularly from politicians who had been made aware that depression costs the community more than any other psychiatric or medical condition. But he said one of the main problems with the treatment of depression was a tendency to include the common forms of “normal” depression or sadness in the same category as clinical depression, despite the fact that the two were vastly different in nature.

“Depression is a ubiquitous human experience,” he said. “It usually spontaneously remits. And it is usually fairly brief, lasting hours or days. What distinguishes clinical depression are three key parameters.

“Firstly, severity. This is a little bit dangerous because it relies on experiential judgment. But certainly the sort of severity which causes suicidal preoccupations would be an example. And not being able to function, being unable to sleep and losing your appetite and so on.

“Secondly, it is impairing. It prevents people from getting to work, which we call ‘absenteeism’, or more commonly from the data, people with clinical depression can get to work, but they don’t know how to fire up. We call that ‘presenteeism’.

“And thirdly, there is persistence: it lasts weeks, months, years.”

Another key problem with the existing treatment for depression was the lack of clear guidelines for distinguishing between “melancholic” (or “biological”) depression and “non-melancholic” depression.

Professor Parker pointed out that 50 years ago, the lifetime risk for clinical depression was relatively rare (between one and three percent) “as clinical depression was principally the melancholic type”. In the latter half of the 20th century, however, depression came to be considered as a single entity, an “it” that “merely varies by severity”.

“If you go to a practitioner with clinical depression these days you are more likely to be treated on the basis of the background training of the practitioner than anything to do with the condition itself,” he said.

“So if you go along with depression type X and see a GP, you will probably get a drug, or with the same type of depression you go to a psychologist you will get CBT (Cognitive Behaviour Therapy), or if you go to a counsellor you will get counselling, go to a lady with a kaftan you will get crystal therapy.”

He said he knew of no other area of medicine where the patient is “fitted to the background training of the practitioner”.

“It is worrying. It is as silly as treating major breathlessness as a diagnostic entity. If you go to a GP who says you have got major breathlessness, you want to know whether you have got asthma, or pneumonia or pulmonary embolism because you know respectively that you are going to receive a bronchodilator, or an antibiotic or an anti-coagulant. Medicine proceeds by chasing causes...”

Professor Parker referred to widely publicised, recent research which appeared to indicate that there was little difference between the response to antidepressants and placebos. He indicated that his own clinical experience working with patients with melancholic depression painted a very different picture. It indicated that while the response to a placebo is only around 10 percent and the response to psychotherapy is only 10 to 20 percent, the response to antidepressants is in the range of 60-70 percent – clearly a dramatic difference.

He argued that the problem with recent studies of the effectiveness of antidepressants was that those who were recruited for research were not the type of patients who presented for clinical treatment.

Another thing that concerned him was that “the message going out to the general community is that if you are depressed go and see your GP”.

“Now GPs vary,” he said, “GPs have a huge range of domains that they have to be competent and involved with. Not all are comfortable with mood disorders, not all have been well trained. So my point would be that, in the same way if you have a cardiac condition, you wouldn’t expect that you would just obey the injunction ... you should see your GP.

“So I think that we need much greater sophistication in our profession and also in the community.”

On the question of exercise and depression, Professor Parker said the research findings were “quite spectacular”. “Some patients have said ‘it generally takes me four hours to get going in the morning, but when I go walking it only takes half an hour’. What is actually happening is that there are real biological changes. And particularly in Sydney, getting out in the morning exposes people to sunlight which stimulates melatonin from the pineal system.”

Professor Parker said it was not just endorphins nor serotonin levels in the brain that were affected, but exercise, particularly in sunlight, had a “cascading” affect on many brain chemicals. It was not merely a psychological affect, but “quite a powerfully biological effect”.

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