It is hard and the moment where you feel the burden or heaviness rather intensely, usually instigated by some present experience — TimeLine

I believe I'm at a disadvantage when trying to use this approach. Being on anti-depressant medication seems to really dull the 'unhappy' emotions, making it difficult to identify the indicators in present experiences. Unfortunately, stopping the medication in order to fully feel isn't a very realistic approach in today's world.

a lot of human capacity and potential is built into us genetically — T Clark

Do you think the search for meaning and purpose is genetic or learned? Do you think it is possible to ignore such thinking and still achieve peace of mind?

These feelings of both anxiety or depression are actual thoughts that you have not yet brought to conscious level and so you are experiencing it emotionally and because you cannot articulate those emotions, you use justifications for them; so sadness and despair equates to existential pointlessness, when really that is not the case but just your way of trying to explain the feelings. Only honesty can motivate any sense of genuine recovery. — TimeLine

I've addressed many emotional issues through therapy, but your comment makes me question whether I still have unresolved issues floating around at the subconscious level. The trouble is in trying to identify what those issues may be, or to pick up on themes that seem to be recurring in my conscious thought processes.

I think the CBT skills I've learned help me address conscious negative thoughts in a positive way - by questioning their validity before rejecting them (or doing something about it if some validity is found), instead of simply repressing the thoughts and related emotions.

You also bring into question the cause and effect relationship between depression and depressive thought. Am I in a position where current stresses or unresolved subconscious issues are causing a depressed state, which leads me to think in depressed ways; or have I resolved the major emotional issues in my life, am I using CBT to effectively manage current stresses, and the depressed thoughts are being derived from my perceived lack of meaning in life, when I desperately want there to be some sort of meaning?

The latter explanation was what led me to think that perhaps if we can believe that we are just really smart monkeys who attach too much importance to their existence, maybe we can forget about ultimate purpose, and just do the things that we instinctively want to do (eat, sleep, survive, procreate, relate, love, minimize suffering) before being tainted by societal ideals (meaning, success, accumulating stuff, looking and acting in certain ways).

@Wosret Precisely the opposite! I regularly practice jiu-jitsu, play soccer, and lift weights. I am in prime physical condition, eat reasonably well, adhere to a pretty strict sleep schedule, have a great girlfriend, a wonderful 2-year-old son, two amazing daughters (10 and 9 years old), a decent relationship with my ex-wife, a comfortable home, a loving and supportive mother, and so on. Yet I am left with this low-grade feeling of apathy toward life in general, and low motivation for change.

The only major external force I can identify that may be regularly affecting my mood is my boss at work, who is quite heavy-handed, and has taken away much of the autonomy I enjoyed working for my previous boss. To deal with this, I believe I have the necessary CBT-based tools.

So I'm left wondering if it's my system of core beliefs about how I think the world should be (or how I've been conditioned to think it should be) that is resulting in this residual feeling of depression, and whether there is some way of thinking that could bring my beliefs more in line with how the world really operates.