为偏执型人格障碍的标题（PPD）认为，这种类型的特点是极不信任的对其他人的行为模式。DSM-IV描述患有这种疾病可能出现寒冷的人，客观的、理性的，而往往显示敌意，讽刺和固执的行为。人们可能会怀疑，PPD最糟糕的人，换句话说，其他人会试图伤害、欺骗或背叛他们。因此，他们发现很难形成亲密的个人关系，因为信任是健康关系的重要组成部分。此外，因为他们不信任的行为，它们会引起别人对自己的敌意。通过认知疗法治疗PPD，贝克& Freedman（1990）认为，最重要的一个方面是获得个人的信任。人们用PPD可能在环境中，他们收到了大量的批评中长大。因此，重要的是不要直接挑战他们的信仰，因为这可以被看作是对自己的攻击。治疗这种疾病的进展很可能是缓慢的。 这两种草图的两个人格障碍，是必要的，非常简短，使症状听起来像他们是绝对的，绝对的。这反映了他们是如何在DSM-IV的描述，意思是他们是如何解释。经验证据表明，严格分类边界的想法，在某些情况下，相当远离现实。
As the title of paranoid personality disorder (PPD) suggests, this type is characterised by pattern of extremely distrustful behaviour towards others. The DSM-IV describes people suffering from this disorder as likely to appear cold, objective and rational, while often displaying hostile, sarcastic and stubborn behaviours. People with PPD are likely to suspect the worst of other people, in other words that other people will attempt to harm, deceive or betray them. As a result of this they find it very difficult to form close personal ties as trust is an important component of a healthy relationship. In addition, because of their distrustful behaviour they tend to provoke hostility in other people towards themselves. In treating PPD through cognitive therapy, Beck & Freedman (1990) assert that one of the most important aspects is gaining the trust of the individual. People with PPD are likely to have grown up in environments in which they received a large amount of criticism. Consequently it will be important not to challenge their beliefs too directly as this could be seen as an attack on themselves. Progress in treating this disorder is likely to be slow. Both of these thumbnail sketches of two personality disorders are, by necessity, extremely brief, and make the symptoms sound as though they are categorical and absolute. This closely reflects how they are described in the DSM-IV and how they are meant to be interpreted. The empirical evidence has shown that the ideas of strict categorical boundaries are, in some cases, quite far removed from reality.