depression

CBG can activate α2 receptors and block CB1 and 5-HT1A receptors (Cascio et al., 2010), suggesting CBG does have therapeutic potential in the treatment of depression.

pain

The interaction between CBG and the α2 receptor (alpha 2 adrenalin receptor) may prove effective in pain control (Giovannoni et al., 2009).

References:

Cascio, M.G., Gauson, L.A., Stevenson, L.A., Ross, R.A., and Pertwee, R.G. (2010). Evidence that the plant cannabinoid cannabigerol is a highly potent alpha2-adrenoceptor agonist and moderately potent 5HT1A receptor antagonist. Br. J. Pharmacol. 159, 129–141.

Giovannoni, M.P., Ghelardini, C., Vergelli, C., and Dal Piaz, V. (2009). Alpha2-agonists as analgesic agents. Med. Res. Rev. 29, 339–368.