Sri Aurobindo
Letters of Sri Aurobindo
Volume IV - Part 2
It is regrettable that this attack [of depression] should recur. Perhaps it was a little my fault – you were or seemed to me going on so well that I was not on my guard against its possible recurrence. During the last two or three days the suggestion did come to me that there might be a turn of that kind, but I was so much in the joy of your music that I did not give it credence.
It is certainly not the answering of questions that will remove the underlying cause of this recurrence. Even if the answers satisfy, it could only be for a time. The same questionings would arise either in a mechanical reiteration – for it is not truly the reason from which they arise, it is a certain part of the vital consciousness affected by the surrounding atmosphere – or else presented from a shifted ground or a somewhat changed angle of vision. The difficulty can only disappear if you remain resolute 
that it shall disappear,– if you refuse to attach any value to the justifications which the mind is made to put forward for your “sadness” under this atmospheric influence and, as you did in certain other matters, stick fast to the resolution to make the Yogic change, to awake the psychic fully, not to follow the voices of the mind but to do rather what the Mother asks of you, persisting however difficult it may be or seem to be. It is so that the psychic can fully awaken and establish its influence – not on your higher vital where it is already awake and growing through your poetry and music and certain experiences so that whenever your higher vital is active you are in good condition, full of delight and creativeness and open to experience; but it is the influence on the lower vital, for it is there as I have already told you that your difficulties are and that this vital depression recurs.