It is important to note that individuals vary greatly, and there is no one-size-fits-all answer to this question. Narcissistic personality disorder (NPD) is a complex psychological condition, and the behavior of a narcissist can be influenced by numerous factors, such as the severity of their NPD, their specific traits, and the dynamics of the relationship.
Narcissists generally display a pattern of self-centeredness, a lack of empathy, and an excessive need for admiration and attention. At the beginning of a relationship, they may be charming and attentive, seeking to win their partner over. However, over time, their self-centered nature may take over, and they may become less invested in their partner's feelings and needs.
The shift in a narcissist's behavior can occur at different points in the relationship. Some narcissists may lose interest in their partners once they no longer serve a specific purpose or stop providing the narcissist with the desired admiration and attention. In such cases, the narcissist may look for a new source of validation elsewhere.
On the other hand, some narcissists might remain in a relationship for longer periods, especially if their partner continues to provide the desired attention or resources. Additionally, the dynamics of codependency or emotional manipulation can keep a partner tied to a narcissist for a prolonged period, even when the narcissist's care and concern for their partner diminish.
Overall, a narcissist's ability to care for their partner tends to be limited by their self-centered nature, and their interest may wane as their partner's utility or admiration diminishes. However, every individual and relationship is unique, and the timeline for when a narcissist stops caring can vary widely. If you suspect you or someone you know is in a relationship with a narcissist and it's causing emotional harm, seeking professional help and support is crucial.