Depression is often used in everyday language to mean straightforward and understandable unhappiness.
This use of the term is best avoided. Instead, the word should be reserved for those who have significant and pervasive lowering of mood leading to difficulties in leading a normal life.
Such conditions can vary from a lifelong predisposition to low mood (known as dysthymia) to depressive episodes that vary in intensity from relatively mild to severe.
Depression is likely to be one of the greatest, if not the greatest, disease burdens of the 21st century.
It’s a common condition, which causes a great deal of suffering and a substantial number of deaths.
Depression leads to disharmony at home, difficulties at work and internal distress. Unfortunately, the condition still attracts much stigma, is not always recognised and, when recognised, is not always adequately treated.
Depression is more common in women than in men, though its most dramatic outcome, death by suicide, is more common in men.
How is depression diagnosed?
The diagnosis of depression is made when several core features are present:
pervasive low mood
loss of interest and enjoyment (anhedonia)
reduced energy and diminished activity.
Other features can also be present, including:
poor concentration and attention
poor self-esteem or self-confidence
ideas of guilt and unworthiness
a bleak pessimistic view of the future
thinking about, planning, or attempting suicide
crying for no reason
disturbed sleep
poor appetite
decreased interest in sex.
Depression is often more difficult to diagnose in men because they do not complain of these typical symptoms so often. They are less likely to admit to distress and if they do consult their doctor, they tend to focus on physical complaints.
How common is depression?
In community surveys, 2 per cent of the population suffer from pure depression at any one time.
Some have a mild form of the illness, some moderate and some severe, in roughly equal numbers.
Another 8 per cent of the population suffer from a mixture of anxiety and depression at any one time. Other people do not have symptoms severe enough to qualify for a diagnosis of either anxiety or depression but have impaired working and social lives and unexplained physical symptoms.
The lifetime rate of depression is 8 per cent for men and 12 per cent for women, and these figures seem to be rising. This trend is worrying and has been much discussed.
Depression is now more frequently diagnosed in younger people than it was previously. This change could well be a result of the increasing social fragmentation, including family breakdown, seen over recent decades.
How is depression treated?
Mild episodes of depression often get better without treatment or will respond to simple measures – such as changes in the social environment or the family situation.
Many other patients can be treated adequately by their GP. Only a minority of patients ought to be referred to specialist psychiatric services.
Patients who should be referred include those:
who are thought to have a high risk of committing suicide
who fail to respond to the usual treatments
in whom the diagnosis is confusing or difficult to make.
If depression co-exists with other conditions that complicate treatment, such as a physical illness, patients should usually be referred to a specialist.
Patients with a psychotic depression, who are troubled by delusions (abnormal beliefs) or hallucinations, should always be referred.
Psychotherapy and counselling
Surveys clearly show that patients prefer a psychotherapeutic approach (counselling or talking about their problems) or at least expect such an approach in combination with their medication.
Evidence indicates that certain specific forms of psychotherapy are useful for patients with mild, moderate and severe depression. Their usefulness is most obvious in the milder forms and in the prevention of further episodes of depression. If someone is moderately or severely depressed they will probably not be well enough to benefit from psychotherapy or counselling at that time.
Men are less likely to ask for this form of treatment.
Antidepressant medication
Since the late 1950s, effective medication has been available for depressive illness.
In recent years, new antidepressants, with fewer side-effects, have become available. These are effective for most people and relatively easy to tolerate.
Whichever antidepressant is used, it’s important to continue treatment for six to nine months after symptoms resolve otherwise symptoms might return quickly. Antidepressants are equally effective in men and women.
Approximately half of all patients with depression only ever have one episode. The others suffer from a recurrent form of the illness.
Taking this into consideration, the doctor might think it wise to prescribe maintenance treatment, which means continuing antidepressants for a number of years to prevent further episodes.
The art of treatment is to combine social, psychological and pharmacological approaches to reduce suffering and mortality. The advent of the new antidepressants and the increasing evidence that certain forms of counselling (problem-solving and cognitive behavioural therapies) do work means that we can be optimistic about the future for people with depression.
However, depression becomes chronic in 10 to 20 per cent of cases.
Psychotic depression
Patients with psychotic depression are seriously ill and will almost always require hospitalisation.
Antidepressant therapy alone is unlikely to be effective.
The treatments of choice are either electroconvulsive therapy (a highly effective but controversial treatment that involves passing electricity through the brain under general anaesthetic) or a combination of an antidepressant with an antipsychotic medicine (a type of medication that treats delusions and hallucinations).