One of the concerns in mindfulness meditation, and remaining mindful in general, is attachment. There are really two different ways of thinking about attachment and mindfulness. One is beneficial, with the possibility of promoting a more secure and happy life, while the other is never beneficial and leads to suffering.
The form of attachment that has the potential to be beneficial stems from psychological research and falls within the topical area known as attachment theory. http://internal.psychology.illinois.edu/~rcfraley/attachment.htm Attachment theory was first developed by John Bowlby, a British psychoanalyst, who described attachment as an evolutionary mechanism for infants to thrive and survive in close proximity to their primary caregivers. Subsequent research on infants found that they generally fell into three major categories, based on the quality of care they received from their caregivers: secure, anxious/ambivalent, or avoidant. Secure infants received consistent, high-quality care from their caregivers, who made sure to provide the nurturing that the infants would need, particularly during times of distress. Anxious/ambivalent infants received inconsistent caregiving, sometimes having their needs being met, but other times being neglected. Avoidant infants experienced a form of abandonment from their caregivers, who were virtually never responsive to the needs of the infants.
More recently, social psychologists have studied the attachment system as it applies to adults. They have identified attachment styles that tend to characterize not only the ways adults behave in close, intimate relationships, but the mental representations or working models that the adults have about such relationships. These working models contain expectations and beliefs about the nature of romantic relationships that are believed to have been influenced by the attachments experienced in infancy as well as other attachments that have been experienced into adulthood. Adults who are insecure tend to be high in attachment anxiety or attachment avoidance, and research has demonstrated that these adults are less satisfied with their relationships, have less trust in their partners, are more prone to mental health problems, are less able to provide support to a distressed partner, and less likely to seek support when feeling distressed. It is therefore beneficial to have a more secure attachment style. Although adults cannot alter the attachments they experienced as infants and children, they can try to develop more secure attachments as adults. For example, adults could work to alter their working models of relationships in an attempt to have more positive expectations about potential partners and more positive beliefs about themselves. Mindfulness suggests the importance of this, by emphasizing the importance of taking care of oneself, learning to nurture oneself, and not jumping to conclusions about the motives of others.
Attachment that leads to suffering is based on a strong desire for things to remain the same. For example, a person might be thrilled with his or her job and never want it to change. Or he or she might enjoy good health and want to hold on to it forever. Because all things change, an attachment to any one state of being will inevitably lead to suffering. Mindfulness in this context means to detach, to enjoy life in the moment, and to expect that things will change and be prepared to accept that. Mindfulness requires an abiilty to let go. Note that having a secure attachment style (in the psychological sense) can help one to deal with loss, at least in the context of a partner or relationship.