If "Molly" is supposed to be the wellknown partydrug that goes hand in hand with "House music" thats really alot more complicated then 6/7 hrs after digestion...
Feelings of depression : usually 3-4 days after and usually only with frequent or too high doses usage... (your serotonine is released, needs time to return to previous levels)
Anxiety : mostly happens when too high dose or not knowing you used it (or not being familiar with it, first time) will mostly happen when substance effects start, 30 min- 1hr after taking, usually goes away when you relax/get active..
irritability / aggression : mostly depending on shortage of sleep the days after using and depending on your character aswell.
Loss of appetite : yeah... low dosage of the active substance has been used in diet pills in the past... usually 30 min. after use upto 12/15 hrs after...
Impulsivity : rather dependent on your character, some get impulsive, some can concentrate more, some want to talk, others want to move/dance/walk (get active in general) usually gone after substance effects wear off...
Insomnia : usually only when too high doses or the day after, again really depends person to person...
Fatique : well.... being active an extra 6-8 hours does that to you
Memory problems : too high doses same like with alcohol and such... using too often and too much may be another thing here.
Impaired ability to pay attention : very dependent on the personality and other factors, often a side effect from other things mentioned here...
Loss of interest in sex : yeah, this is definitely something else then that certain partydrug lol...
Then again, it's a bit like the notes for medicins ; if a certain number of the testers experienced something it gets included in the list even if 95% never had that problem.