My husband is on anti-depressants and they have really helped him with his anger too. (I wish he would do therapy, but the meds seem to provide what he wants right now.) Life events can lead to chemical imbalances and so to depression. So it is not just a case of depression is caused either by events or chemicals. Stressful and traumatic events lead to changes in our brain chemistry, levels of neurotransmitters, etc. That is why psychotherapy can help with depression, as it gives you ways to modify your biochemistry. When I solve my problems with life events, my biochemistry "improves", and depression is alleviated. Good luck with the CBT. Hope you will report in and let us know what specific things work for you!