Many psychiatric drugs can cause dry mouth, known medically as xerostomia. Unbeknownst to many doctors, dentists and patients, this side effect can severely increase the risk of tooth decay, fungal infections, gum disease and nutritional problems.

A recent study found that persons taking antidepressants and/or antianxiety drugs had almost four times the rate of tooth decay than the control group. The difference was attributed to dry mouth, as the lack of saliva's antibacterial and antiviral properties permits rampant bacterial growth. Additionally, those patients who abate the condition with sugar-containing candy or gum further feed those destructive bacteria.

Dry mouth may not be noticeable on initiating a medication, as there may be a gradual decrease in saliva production. Be alert to the possibility of this seemingly innocuous side effect. In most cases, it can be alleviated with water, ice chips, chewing sugarless gum and/or sucking sugarless candy. For more serious dry mouth, there are over-the-counter or prescription saliva substitutes, and also saliva-inducing prescription medications.