Why don't I feel like having sex with my boyfriend anymore?

Dear Sarah,

I am in a long-term relationship for about 3 years now, and we have lived together for half of that. We had a healthy, passionate sex life for almost two years, and both felt satisfied. I was very active previous to this partner, and felt confident in my sexuality.

But then my sex drive slowed gradually, and initially, I put it down to living together and work stress. Now I feel more comfortable and stable in my job than ever, but my sex drive is still non-existent.

I dread evenings and weekends because I know that my boyfriend will want to have sex, but I might not be able to.

Dear anonymous,

Despite all your efforts and wishes, you cannot get desire going in your head. You feel so sad about it, because you have not consciously changed, it is more likely your unconscious that has changed and is responding by powering down, causing upset, and then switching off.

Are there things to say that cannot be said between you? Can you talk about this together? Can you ask yourself some questions about being "turned on"?. Sex drive has been the subject of much research and speculation. There is no specified definition of female desire and certainly no clear understanding of how it works. It may be that it is affected by the menstrual cycle, that there are patterns, but in our modern Western society, reproduction and sexual desire have become separated and now the biological component is only a part of the whole picture.

Some people use Viagra to help and there is some evidence emerging that mindfulness has a place too. Often, distress about lack of libido is caused by the partner who has higher levels of desire and makes the other person in the relationship explain it and feel bad about it. Having sex out of guilt and obligation makes it a dreaded chore, but there are ways to have sex where one pleasures the other, which could take the pressure off your active enjoyment.

The imperfections between you and your boyfriend may well be the key to the problem. At the moment it feels like the situation has caused insecurity and doubts in you both and a bit of a deadlock in how to go forward. The problem is not just yours, it is between you and about your relationship.