Occasionally, a drug is used to treat a particular mental illness but also ends up affecting other non-related neurotransmitters. this contributes to

the experience of side effects

Explanation:

Since drugs act  indiscriminately on neurotransmitters and in the process alter the balance of other substances common negative side effects are:

   Drowsiness. Dizziness Restlessness. Weight gain

Dry mouth and other mucose will have less segregation, or the contrary will happen.

Drugs act on the sympathetic and parasympathetic system. Some antidepressants or anxiety-related medicine will potentially cause imbalances that the body will be able to adjust after some weeks.

An important element to consider is that medication should endure a period of adaptation and be sustained, and avoid suddenly stoping the consumption without a plan of detoxicating.

The effects apply to the state of mind, as feelings of being depressed or paranoid can happen, personality changes, headaches, and vomiting.