is an antidepressant drug which has a much varied mechanism when compared with other antidepressant drugs. Mirtazapine increases the level of the neurotransmitter norepinephrine and serotonin in the brain by binding to the presynaptic adrenoreceptors which enables the continual release of serotonin and norepinephrine into the synaptic clefts of neurons. Some side effects to Mirtazapine include- sedative effects and weight gain, both of which directly depend on the level of dosage.