Clinical depression or major depression is a mental disorder characterised by a pervasive low mood, low self-esteem, and loss of interest or pleasure in normally enjoyable activities. Depression is a disabling condition that adversely affects a person’s family, work or school life, sleeping and eating habits, and general health.
Depression is now recognised by doctors as a potentially serious medical condition. The diagnosis of major depressive disorder is based on the patient’s self-reported experiences, behaviour reported by relatives or friends, and a mental status exam. The most common time of onset is between the ages of 30 and 40 years, with a later peak between 50 and 60 years.
Approximately 3.4 per cent of people with major depression commit suicide, and up to 60 per cent of all people who commit suicide have depression or another mood disorder.
Most patients are treated in the community with antidepressant medication and some with psychotherapy or counselling. Medications may relieve depression only partially, may not help, or may stop working after a while. Treatment-resistant depression (TRD) occurs when 4 or more adequate antidepressant treatments have not provided desired improvement. There are also as many as four million individuals that suffer from this type of depression that is known as ‘Treatment Resistant’. These are people that have tried everything, medication, therapy, shock treatments, you name it, but all have proven to be ineffective.
Neuro science is now offering a surgical procedure to individuals who feel that all other options have failed them and are desperate enough to try the surgery. This type of surgery involves drilling holes in the patient’s head and placing electrodes in an area of the brain known as ‘Area 25’. Deep brain stimulation is Neurosurgical treatment for chronic depression in which the brain is stimulated with electrical impulses. Deep brain stimulation is an invasive form of brain stimulation treatment for depression.
Deep brain stimulation
Deep brain stimulation works much like a pacemaker for your brain. With deep brain stimulation, a neurostimulator device is implanted in your chest and electrodes are implanted in your brain. Wires under your skin connect the electrodes to the neurostimulator. The neurostimulator sends electrical signals to your brain, affecting mood centres and improving depression symptoms. This surgery is reversible and the electrodes can be adjusted without further invading the brain. It is performed under a local anaesthetic, and the changes in patients could sometimes be seen ‘almost instantly’.
Vagus nerve stimulation
Vagus nerve stimulation (VNS) has a privileged place in the management of drug-resistant depression depressive disorder. Despite the fact that surgery is needed to implant the stimulating device, the option of long-term use largely devoid of severe side effects would give this treatment modality a privileged place in the management of drug-resistant depression.
Vagus nerve stimulation (VNS) in humans refers generally to stimulation of the left vagus nerve at the cervical level using the NeuroCybernetic Prosthesis. This equipment consists basically of three parts:
The implantable, multiprogrammable bipolar pulse generator
Two helical electrodes, which are wrapped around the vagus nerve and are linked to the pulse generator by a bipolar lead; and
A programming wand linked to a computer running programming software, which allows non-invasive programming. The pulse generator is implanted in a subcutaneous pocket in the left chest wall, whereas the electrodes are attached to the vagus nerve. VNS improves depressed mood by affecting the metabolism and thus the function of limbic structures and altering the concentration of monoamines in the brain.
It is interesting and impressive to see how the patient’s lives change over time. They go from being withdrawn and not interacting to going back to work, and show marked improvement in self-care and social function. They live their lives much more fully than they were when they were stuck in the grip of depression.