Patients with OCD frequently have a parent or life partner who is involved in the illness. There are two pathologic forms of such involvement. The first involves facilitation. By pleading, nagging, demanding, or threatening, the patient will induce others to accommodate to his or her fears and concerns. The facilitator may perform rituals for the patient or permit the patient to control the environment or common time. Facilitation allows the illness to flourish without normal constraints.
The second pathologic interaction is the antagonistic–defensive dyad. Such relationships are adversarial. The antagonistic partner acts in a caustic, demeaning manner and does not understand or accept the nature of the illness. The OCD symptoms are viewed as willful antagonism. The patient reacts in a hostile, defensive manner that aggravates the partner. The hostility, instability, loss of self-esteem, and stress in these interactions exacerbate the symptoms of OCD and lead to further antagonism.
In both forms of pathologic relationship, the patient may use his or her symptoms to control the other person. This can be an unconscious or pseudoconscious process. Facilitating interactions can lead to circumstances in which the patient uses his or her illness to obtain material and emotional benefits. In antagonistic–defensive interactions, symptoms may serve to irritate and frustrate the hostile partner—one of the few mechanisms available to the patient to "get back at" that partner. In both pathologic interactive modes, the secondary gains associated with the symptoms can further ingrain the disorder.