How do methylphenidate and dexamfetamine affect catecholamine activity in the central nervous system?

Methylphenidate and dexamfetamine increase catecholamine activity at central nervous system synapses, particularly affecting noradrenaline and serotonin levels. This stimulation can lead to various effects such as euphoria and reduced appetite, although the exact mechanism of action in conditions like ADD and ADHD remains unknown.