We have different kind of neurotransmitters in brain which have different effects on our system like Dopamine, Acetylcholine, Serotonin and GABA. Dopamine & Acetylcholine are excitatory while serotonin and GABA are inhibitory (calming effect).
Men and women both produce serotonin hormone in their brains which is linked to optimism, comfort and contentment. Its required to effectively cope with stress. Women depletes serotonin stores much more faster than men due to much more activity, emotions and thoughts in brain plus now a days women are taking their jobs as stressful as to men so even much more faster depletion of serotonin. This is the reason why women are now a days more stressed and are at large risk of depression in comparison to men. Women who starts taking anti depression drugs they are actually increasing cortisol which leads to more carbs and sweet cravings, less energy production, increased risk of osteoporosis and ultimately weight gain also.
Supplements to boost serotonin levels if you are deficient are: Fish oil, Magnesium, B vitamins, Melatonin and tryptophan