Negative ions are exceedingly beneficial for a person's metabolism as a means of enhancing human behavior. They act in a complex mechanism to bring about hormone and biochemical reactions in the body and brain. It is impossible to get an overdose of negative ions, which act like pure water in washing away dirty poisons. Generally, the more negative ions you are exposed to, the better and more uplifted you feel. The limiting factor in ionic foot baths is the amperage, you always want over an extended time in a session to stay under 2.5 amps.
Positive ions, or the lack of negative ions, may cause serotonin hyperfunction syndrome or "irritation syndrome" and it involves sleeplessness, irritability, tension, migraine, nausea, heart palpitations, hot flashes with sweating or chills, tremor and dizziness. The elderly become depressed, apathetic and extremely fatigued.
Human mood disorders (depressions) are effectively treated with drugs which specifically block the re-uptake of serotonin into the presynaptic axon terminal, for example fluoxetine (Prozac) and Zoloft. This suggests that positive ions may play a part in this condition and the condition may be safely treated with negative ion therapy.