Same story as with eczema, told over & over again. Psoriasis is hereditary & is often stress related.
Treat often with UltraViolet (SUN) which helps with the production of Vitamin D & boosts serotonin levels (feel good hormone) as well as melanin production.
Basically the skin & often scalp is totally freaked out & over-producing cells to try & protect itself ( the same could be said for the mood). So you need to avoid any harsh cleansers or washing powers, & put as much Magic Balm on affected areas as often as possible. This will seal in all the active ingredients & stop the kerfuffle.
Remember to use for at least 4 weeks, to allow your skin cells to fully turn over, & become used to the new 'normal'.
Eventually that will help your mood as you will be psoriasis free too!