As I wrote in the preamble to this presentation, anti-depressants have their place in the treatment of fibromyalgia, as they are useful in the treatment of hypothyroid patients with depression. It was noted in patients with FMS lower than normal serotonin levels. Antidepressants are used to increase serotonin levels. Serotonin is a neurotransmitter. Neurotransmitters are the language of the nervous system that allows nerve cells to transmit nerve impulses between themselves or between a neuron and other varieties of cells (muscles, glands). Anger, hunger, sleep, thinking, (among others), are the results of the action of these molecules of communication. Overall, individuals with fibromyalgia seem to perceive pain differently than others. There seems to be a disturbance of perception threshold of pain. Fibromyalgia seems to be explained by the inadequate functioning of neurotransmitters. Abnormal central pain control may explain fibromyalgia. Some neurotransmitters such as serotonin are accused of being mediators of fibromyalgia as they allow communication of pain signals.
Medical teams involved in research on fibromyalgia believe that there is a disturbance of the interpretation of pain by the central nervous system. For this reason we speak of poor integration of nociceptive stimuli. The term nociceptive means anything that is related, everything that captures the painful stimuli. This phenomenon is the result of a malfunction of certain areas of the brain, particularly the thalamus and caudate nuclei, which are the basal ganglia of the brain. Recall the existence of a genetic predisposition in fibromyalgia.
But not all patients with fibromyalgia do respond effectively to antidepressants. Some must stop treatment in the early days due to side effects, with a “zombie” effect reported by many patients. They sometimes increase appetite with a dramatic gain of weight over time. Efficiency can vary from one drug to another, and it is the same, when it exists, that patients are depressed or not. The FMS non-depressed subjects were simply less impacted on their daily lives. When depression and anxiety occur, they are most often the result rather than the cause of fibromyalgia.