Cannabis is truly a wonderful and amazing plant. There are many strains that can cure both bodily and mental ailments. Moderation is important, as heavy use of phytocannabinoids will downregulate your body's production of endocannabinoids.
Anecdotally, C. Indica dominant hybrids (Gorilla Glue #4[0] is my favorite) put me in a trance that allows me to focus on a coding task for hours. The only side effect is that my eyes are half-closed. The increase in mental acuity is on par with substituted phenethylamines or eugeroics.
The usual disclaimers apply: IANAD, don't listen to Internet strangers for medical advice, etc.