DSM-5
The most recent fifth edition of the Diagnostic and Statistical Manual of Mental Disorders stresses that a personality disorder is an enduring and inflexible pattern of long duration leading to significant distress or impairment and is not due to use of substances or another medical condition. The DSM-5 lists personality disorders in the same way as other mental disorders, rather than on a separate axis, as previously.DSM-5 lists ten specific personality disorders: paranoid, schizoid, schizotypal, antisocial, borderline, histrionic, narcissistic, avoidant, dependent and obsessive–compulsive personality disorder. The DSM-5 also contains three diagnoses for personality patterns not matching these ten disorders, but nevertheless exhibit characteristics of a personality disorder:
Personality change due to another medical condition – personality disturbance due to the direct effects of a medical condition. Other specified personality disorder – general criteria for a personality disorder are met but fails to meet the criteria for a specific disorder, with the reason given. Unspecified personality disorder – general criteria for a personality disorder are met but the personality disorder is not included in the DSM-5 classification.These specific personality disorders are grouped into the following three clusters based on descriptive similarities:

Cluster A (odd or eccentric disorders)
Cluster A personality disorders are often associated with schizophrenia: in particular, schizotypal personality disorder shares some of its hallmark symptoms with schizophrenia, e.g., acute discomfort in close relationships, cognitive or perceptual distortions, and eccentricities of behavior. However, people diagnosed with odd-eccentric personality disorders tend to have a greater grasp on reality than those with schizophrenia.
Trigeminal autonomic cephalalgia (TAC) is the name for a type of primary headache that occurs with pain on one side of the head in the trigeminal nerve area and symptoms in autonomic systems on the same side, such as eye watering and redness or drooping eyelids. TACs include

Cluster headache
Paroxysmal hemicrania (chronic or episodic)
Short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT)
Short-lasting unilateral neuralgiform headache attacks with cranial autonomic symptoms (SUNA)
Long-lasting autonomic symptoms with hemicrania (LASH)TACs can be differentiated by the length and frequency of recurrence of the headaches.Treatment for TACs varies depending on the exact type, but can include medication such as Indomethacin (in the case of chronic paroxysmal hemicrania) or acute and prophylactic therapy (in the case of cluster headache). == References ==