The belief that does the most damage
The implicit model conveyed by films is simple: the urge comes first, action follows. When that is no longer the case, we conclude that something has gone out.
The work of Canadian physician Rosemary Basson, published in the early 2000s, proposed another model: for many people, and particularly in long-term relationships, desire does not precede arousal, it follows it. You do not start because you feel like it; the wanting comes once you have started, in a favorable context.
Accelerators and brakes
Another useful contribution is the idea that desire depends on two simultaneous systems: what activates it and what inhibits it. This framework, drawn from the work of researchers at the Kinsey Institute and made accessible to the general public by researcher Emily Nagoski, completely shifts the question.
Usually we try to add accelerators: an evening out, an outfit, a setting. Yet in settled life, the problem far more often comes from the brakes — fatigue, mental load, unresolved tension, feeling unattractive, fear of being interrupted.
The productive question is therefore not "what could spark desire?" but "what kills it, and what can we remove?". It is often less romantic and much more effective.
The tension between security and desire
Psychotherapist Esther Perel has extensively documented a paradox of lasting couple life: love feeds on closeness, predictability and security, while desire feeds on distance, novelty and a share of the unknown.
A very fused, perfectly organized life together can therefore, without the slightest emotional problem, reduce the space desire needs. This is not a flaw in the relationship: it is a structural tension to be managed, not solved.
Concretely, this argues for preserving otherness: separate activities, spaces of one's own, and continuing to see the other as a distinct person rather than as an extension of the household.
Duoly, the couples appThe daily appointment that puts the conversation back at the center.Habituation, and what counters it
A third mechanism is more general: we get used to what is stable, including what we enjoy. This adaptation phenomenon, well described in the psychology of well-being, explains why the same situation produces less and less effect as it becomes predictable.
Psychologist Arthur Aron's research on self-expansion offers a useful counterpoint here: couples who regularly share new and somewhat stimulating activities report a better relationship quality than those who share merely pleasant and familiar ones.
The criterion is not how romantic the activity is but how unusual — preferably something neither of you masters, where you see each other hesitate and learn.
When to worry, and when to seek help
A drop in desire becomes something to address when it comes with suffering for one of the two, when it settles in durably, or when it becomes impossible to bring up without conflict.
Medical advice is warranted in case of sudden change or pain: ongoing treatments, hormonal variations and depressive states have direct, known effects on desire. These are frequent causes, and they can be treated.
Support from a sex therapist or couples therapist helps most when the conversation itself is stuck — which is the most frequent case.
This article is not medical advice.