A nasal spray could be a new way to tackle depression. Based on a horse tranquilliser, the spray gets to work in as little as two hours, far quicker than widely used medications that can take weeks to kick in.
The liquid contains a compound called esketamine, which is thought to act on the brain chemical glutamate to restore connections between brain cells. It’s used in far smaller doses than the street drug ketamine.
The U.S. regulator, the Food and Drug Administration, last week approved the use of the spray for patients with depression that does not respond to other treatments.
The liquid contains a compound called esketamine, which is thought to act on the brain chemical glutamate to restore connections between brain cells (stock image)
Five UK centres are taking part in a long-term trial of the spray, which is used twice a week. Depression is a mood disorder that causes persistent feelings of sadness and loss of interest. Clinical depression is estimated to affect one in 15 adults at some time.
It is the result of changes in brain chemistry, and causes range from genetics and changes in hormone levels, to chronic medical conditions, stress and grief.
The most common treatments are drugs called selective serotonin reuptake inhibitors (SSRI). These work for some — not all — patients, and can take between two and six weeks to exert full effects. A study of 3,000 cases of severe depression in the American Journal of Psychiatry found that less than 30 per cent had remission after taking SSRIs.
A nasal spray has been investigated, as it offers quicker relief because the drug gets to where it is needed in the brain without being processed through the body.
Depression is a mood disorder that causes persistent feelings of sadness and loss of interest (stock image)
While most existing drugs act on the brain chemical serotonin, which is involved in mood regulation, esketamine acts on another chemical, glutamate.
The surprising reasons for a flushed face. This week: Hormones
Hot flushes are one of the most common symptoms of the menopause. A rise in facial temperature causes blood vessels just under the skin to dilate, resulting in reddening.
One theory is that hot flushes are down to a malfunctioning of heat control mechanisms in the brain, possibly triggered by changes in oestrogen and other hormones around the time of menopause. Flushes are occasionally seen in men, with a drop in testosterone implicated — most likely as a result of androgen deprivation therapy, a prostate cancer treatment which restricts the production of testosterone, so it can’t stimulate cancer cell growth.
The NHS says hormone replacement therapy (HRT) is an effective treatment. But other therapies can help, including vitamin E, which has anti-inflammatory effects, and even antidepressants, which regulate hormones, such as serotonin, that influence body temperature.
Research has shown that problems with connections between nerve cells in the brain may lead to depression. One theory is that it is associated with a wasting away of nerve cells in brain regions that control mood and emotion, possibly as a result of stress.
Glutamate, released by nerve cells in the brain, is one chemical responsible for sending signals between nerve cells. However, too much glutamate is bad for the brain, leading to nerve cell loss, and has been linked to depression.
Esketamine works by blocking excess glutamate and this is thought ultimately to repair and restore nerve cells. Animal studies dating back to the Fifties have suggested drugs that act on glutamate may be effective for depression. But it was not until 2000 that the first small study in humans found similar effects.
One new study, reported in the Journal of Psychiatric Research, analysed data on 14 patients given esketamine.
Results showed four of the seven people using the spray responded to treatment after two hours and three
