The word "Lunatic" which means crazy has been derived from the word Lunar which means Moon. Hence moon is one of the most important planet when you consider mental health/ illness of the subject.
The following placement makes a person mentally afflicted:
1. Debilitated moon with a malefic
2. Moon aspected by a natural malefic by PAC
3. Moon placed in "Ashlesha" is also a strong indication amongst other negative indication.
4. Moon afflicted by one or more malefic by PAC
5. Malefic planets in 12th & 2nd from moon also affects moon.
However any of the above mentioned combination does'nt mean the person is crazy or mentally afflicted it only means that the seed of illness is already inside him it may or may not sprout.
An afflicted mercury in terms of PAC will definitely need to be analyzed like the moon.
Not only moon but at times Shani - Mangal ie. Saturn - Mars combination also has its role to play in this.
I will request all the budding astrologers/ enthusiatics to not immediately jump to a conclusion when you see an afflicted moon/ mercury and tag a person "Sick" cos there is more to it. Along with this lagnesh and its placement the D9- D1 will give the complete picture.
In most cases of psychopaths, serial killers, it has been observed that severely afflicted planets like moon - mercury or Saturn - Mars have caused the illness which was beyond repair and resulted into a chronic illness which made them cause many lives etc.
This doesn't mean that every person in the world with the afflicted moon is a killer, psychopath.
One of the best example is the chart of a serial killer Ted Bundy, you can see the moon was in scorpio hence debilitated and was highly afflicted by many planets PAC effect.
Neha Pradeep Saini