[header] How to tell if your partner has a personality disorder [title] Understand cluster a disorders. [step] Cluster a personality disorders are defined by behavior that may appear strange or eccentric to other people. Someone with a disorder from this group may have unusual ideas or suffer from distorted thinking. 
Poor social skills and social isolation are common in people with these disorders. Paranoid, schizoid, and schizotypal personality disorders are included in cluster a.