I'd recommend a full spectrum as you're getting all of the beneficial compounds from the plant, and they can work synergistically to enhance benefits. Isolate is only CBD, all the other compounds have been stripped away or filtered. Broad Spectrum still contains many of the beneficial effects of Full Spectrum but it still has some compounds (namely THC) stripped from it. You can find a lot of great info at ProjectCBD.org as well.
A 2013 study published in the British Journal of Clinical Pharmacology reports that CBD protects against the vascular damage caused by a high glucose environment, inflammation or the induction of type 2 diabetes in animal models; plus, CBD proved to reduce the vascular hyperpermeability (which causes leaky gut) associated with such environments. (18)
However, cannabidiol as an anxiety reducer has almost none of these issues. One study had 24 participants who took either 600 mg of CBD or a placebo drug. In a speaking test that followed, the group which underwent CBD treatment showed less anxiety. They also had a smaller degree of cognitive impairment and felt less discomfort overall as they spoke. In other words, their results were better than those of the placebo group.
To meet legal standards in the United States, CBD oil and other products may contain up to 0.3% THC; low enough to avoid all psychoactive effects, but enough to potentially appear on a sensitive drug test. Kat’s Naturals, however, sells CBE products of the utmost purity, containing 0% THC, and free from pesticides, chemicals, and contaminants. The company works with organic hemp cultivated in the Netherlands, and extracts its CBD using a broad-spectrum critical CO2 process, retaining a high amount of omega 3’s and 6’s (heart-healthy fats), vitamins, and phytochemicals. Kat’s Naturals is also big on using synergistic essential oils- also organic- to enhance their CBD’s therapeutic effects. The best CBD for anxiety in their lineup is Relax, a tincture that combines 300 mg CBD, Organic Hempseed oil, and wild orange essential oil, along with Hops oil, a potent calming botanical which has been used to promote sleep since ancient times. Kat’s Naturals recommends this product explicitly as a great CBD for anxiety, as well as for promoting sound sleep, making this an excellent choice for anxiety-induced insomnia.