Depression and Neurotransmitters
Depression is a serious psychiatric condition involving the mood, mind and body of patients. During the depressive state, people feel hopeless and experience an overwhelming sense of hopelessness, worthlessness and helplessness.
Neurotransmitters are synthesized within the presynaptic nerve termination, stored in vesicles and - subsequently - released in the synaptic wall (the space between the presynaptic and postsynaptic nerve terminations) in response to certain stimuli.
Once released from the deposits, monoamines interact with their own receptors - both presynaptic and postsynaptic - in such a way as to carry out their biological activity.
After carrying out their function, the monoamines bind to the receptors responsible for their reuptake (SERT for the reuptake of serotonin and NET for the reuptake of noradrenaline) and are brought back inside the presynaptic nerve termination.
Tricyclic antidepressants are able to interfere precisely with the reuptake mechanism of monoamines. In this way they increase its transmission and allow the improvement of the depressive pathology.
History
Before 1950 there were no real antidepressant drugs, or at least not in the way we understand them today. The only therapies used in the treatment of depression were based on the use of amphetamine stimulants or on electroconvulsive therapy. However, the use of amphetamine drugs was often ineffective and the only result was an increase in the patient's activity and energy. Electroconvulsive therapy, on the other hand - although it was effective - terrified patients because it caused pain.
The first antidepressants were discovered in the late 1950s. As with many of the discoveries that changed human life, the synthesis of antidepressants did not arise by design but by chance.
The progenitor of tricyclic antidepressants - l "imipramine - was discovered by the Swiss psychiatrist Ronald Kuhn while he was looking for new compounds similar to chlorpromazine for the treatment of schizophrenia.
Between 1960 and 1980, TCAs became the main therapeutic agents used in the treatment of depression.
However, TCAs - in addition to inhibiting the reuptake of monoamines - are also able to act on many other systems of the body, causing a wide range of side effects.
With the discovery of more selective antidepressant drugs - such as selective serotonin reuptake inhibitors (SSRIs), selective norepinephrine reuptake inhibitors (SNRIs) and non-selective norepinephrine and serotonin reuptake inhibitors (NSRIs) - TCAs were not most used as drugs of choice for the treatment of depression.
Today, TCAs play a minor role in psychiatry but still retain some importance.