Passiflora Incarnata is classified as a hypnotic (helps you sleep), analgesic (pain relief, especially musculoskeletal discomfort and joint inflammation), hypotensive (lowers blood pressure), a nervine (relaxes the nervous system, reduces stress) , an antispasmodic (reduces spasms & pain in involuntary & voluntary muscles),  & an anti depressant. 
I personally use the flowers, leaves, and stems and make tinctures, elixirs, and teas. However, traditionally the ancestors would decoct and use the roots as a means to fight infection, as anti inflammatory, and to help heal wounds. I know they also enjoyed the leaves and flowers as well, but today, most of the herbal world sticks to just the leaves, stems, and flowers for their preparations.  
The passion flowers themselves remind me of the cyclical nature of all living things, including the way our minds often go in circles when we think. This is definitely something I’ve struggled with & it honestly creates a lot of anxiety and inner turmoil. Passionflower tea or tincture really help me in those times when anxiety and worry are running my thoughts in circles. 
She’s also really helpful in times of over stimulation where you feel like everything is just simply too much. Whether it be large crowds, interacting in social settings, too many sounds, too many lights, etc. Passionflower helps in those situations where your brain is processing (or trying to) all too much at one time. 
I often recommend passionflower to people who are struggling with painful menses, stress, anxiety, panic, or insomnia, and also to people who are dealing with restless leg syndrome. It’s a gentle yet extremely effective remedy, even for children. I have a teenager who deals with anxiety at times & passionflower tea always stops the spiral. 
This information is for educational purposes only, speak to your doctor before using if you are on any medications, pregnant, or nursing. These statements &  products have not  been approved or regulated by the FDA. This product is not meant to diagnose, cure, or prevent any disease.  Talk to your health care provider before using, especially people who are taking prescription medications, have health issues, are pregnant or trying to become pregnant.