Tranquilizers are used for the treatment of stress, fatigue, mild and severe mental diseases. They relieve anxiety, stress, irritability, or excitement by inducing a sense of well-being.

Noradrenaline is one of the several neurotransmitters which play an important role in mood changes.

If the level of noradrenaline in the body is low for some reason, then the message transfer process becomes slow and the person suffers from depression.

In such cases, antidepressant drugs are used. These drugs inhibit the enzymes which catalyze the degradation of noradrenaline.

If the enzyme is inhibited, then the neurotransmitter noradrenaline is slowly metabolized and can thus activate the receptor for longer periods thereby counteracting the effect of depression.

Tranquilizers form an essential component of sleeping pills.