In discussing mood disorders, I like to separate the discussion into two parts: symptom relief and alleviation of the possible underlying cannabinoid deficiency that may be contributing to your depression and anxiety.
For immediate symptom relief of depression, the sativa and sativa dominant strains such as Jack Herer, Blue Dream, Green Crack, and a host of others work. However, if you also have anxiety, Sativa’s have been known to increase this felt sense. For anxiety, strains like Grand Daddy Purps, among others seem to work. You will have to find the strains that work for you and one may work better at one time and another may work better at another. The terpenes in cannabis also contribute to your sense of well being and I would investigate aromatheraphy as a less expensive and perhaps more effective way to get the terprenes into your system than smoking weed.
To alleviate the chronic condition of depression and anxiety, I would suggest taking a high CBD/low THC tincture to start 2-3x a day, but base your dosage on the recommendation of whatever brand of product you purchase. We have found that CBD patches and different ratio patches 18:1 or 4:1 patches work as well. These modes of administration allow for consistent bio availability and thus allow your body to work full time on helping you get better (Contrasted with smoking, which only gives your body 3-6 hours of bioavailability). We have seen a lifting of mood within a day or two, but sometimes longer.
On another note, moderate exercise, meditation, and watching what you eat (start taking an Omega 3 supplement and avoid processed foods) can also help with mood disorders.