Attachment Theory was first conceived by John Bowlby in the late 1950s, and developed by others, notably Mary Ainsworth. In my mind it remains the single most important theory we have in therapy.
Bowlby observed that an infant strives to form a bond - to attach - to its caregiver and that this bond is essential for survival and emotional well-being. The way in which the main caregiver responds will set the ground for the infant’s attachment style*.
Curiously, this drive to attach to another person persists throughout life, long after a person has become physically independent and is one of the main drives behind seeking a partner. This may be to do with maintaining a stable bond in order to raise children, yet it continues long after children have grown up.
While Freud emphasised the sex drive, attachment seeking appears to be at least an equal drive in pair-bonding. In adulthood, the attachment figure is likely to be a partner, spouse, or may be a parent or a close friend or family member.
In their book Adult Attachment Feeney and Noller observe that such a relationship is qualitatively different from other friendships: “once attachment to a particular figure has formed, proximity to that figure provides security that other figures cannot”.
While the process of bonding may happen quickly, adjusting to loss (to detachment) can take much, much longer. Feeney and Noller note that a sense of attachment persists even after the other person is no longer available, through separation or death. This is why the loss of a parent or partner can be so painful.
Any loss needs to be grieved, sadness and anger felt and released. This needs then to be followed by comfort and soothing. When the person being grieved is the one who would have offered comfort, then grieving and mourning can be extremely difficult, and it may seem there is no way out of it.
At these times it is important to find comfort and warm support from others, friends, family or maybe a therapist. A therapist can help you develop care and compassion within yourself, so that you can self-soothe and take care of yourself through a difficult time.
* there are many websites offering a good introduction to attachment style - for example