Initially fasting can make emotional stress worse so that's something to watch out for. As the body goes into ketosis it naturally makes all our neural transmitters fire much more cleanly, something medications try to do with only limited success. Therefore it is actually better than taking anti-depressants, acts far more quickly AND it doesn't have the detrimental side effects. However for those who are susceptible to it there is also the usual struggle through the changeover period that anyone who has tried those meds knows very well. The struggle should only last a few days, up to 5 maybe at the most. Again much more efficient than medication which can take months to build up to it's relatively weak full effectiveness. The challenge still is to make it past those harder days.