An unstable family environment predicts the development of the disorder, while a stable family environment predicts a lower risk. One possible explanation is that a stable environment buffers against its development. Self-complexity
Self-complexity, or considering ones self to have many different characteristics, may lessen the apparent discrepancy between an actual self and a desired self-image. Higher self-complexity may lead a person to desire more characteristics instead of better characteristics; if there is any belief that characteristics should have been acquired, these may be more likely to have been experienced as examples rather than considered as abstract qualities. The concept of a norm does not necessarily involve the description of the attributes that represent the norm: cognition of the norm may only involve the understanding of "being like", a concrete relation and not an attribute. Thought suppression
A 2005 study found that thought suppression, or conscious attempts to avoid thinking certain thoughts, mediates the relationship between emotional vulnerability and BPD symptoms. A later study found that the relationship between emotional vulnerability and BPD symptoms is not necessarily mediated by thought suppression. However, this study did find that thought suppression mediates the relationship between an invalidating environment and BPD symptoms. Developmental theories
Marsha Linehans biosocial developmental theory of borderline personality disorder suggests that BPD emerges from the combination of an emotionally vulnerable child, and an invalidating environment. Emotional vulnerability may consist of biological, inherited factors that affect a childs temperament.
Retinal migraine is a retinal disease often accompanied by migraine headache and typically affects only one eye. It is caused by ischaemia or vascular spasm in or behind the affected eye. The terms "retinal migraine" and "ocular migraine" are often confused with "visual migraine", which is a far-more-common symptom of vision loss, resulting from the aura phase of migraine with aura. The aura phase of migraine can occur with or without a headache. Ocular or retinal migraines happen in the eye, so only affect the vision in that eye, while visual migraines occur in the brain, so affect the vision in both eyes together. Visual migraines result from cortical spreading depression and are also commonly termed scintillating scotoma. Symptoms
Retinal migraine is associated with transient monocular visual loss (scotoma) in one eye lasting less than one hour. During some episodes, the visual loss may occur with no headache and at other times throbbing headache on the same side of the head as the visual loss may occur, accompanied by severe light sensitivity and/or nausea. Visual loss tends to affect the entire monocular visual field of one eye, not both eyes. After each episode, normal vision returns. It may be difficult to read and dangerous to drive a vehicle while retinal migraine symptoms are present. Retinal migraine is a different disease than scintillating scotoma, which is a visual anomaly caused by spreading depression in the occipital cortex at the back of the brain, not in the eyes nor any component thereof.