The comorbidity of post-traumatic stress disorder (PTSD) with a range of other mental disorders is common. This comorbidity is often attributed to either overlapping symptoms between PTSD and other disorders or to the variety of psychiatric conditions that can arise in the wake of exposure to a traumatic experience. However, this comorbidity may also be due to the fact that PTSD can moderate the onset or severity of other psychiatric symptoms or disorders. This is an important issue, because it has implications for how patients affected by the array of symptoms that can emerge after trauma may be most efficiently managed.

Our knowledge of how PTSD can impact other disorders rests on longitudinal studies that have assessed PTSD and other conditions, and have typically conducted cross-lagged or time-series analyses. This approach allows us to determine the extent to which each condition impacts other disorders at later assessments. Convergent evidence indicates that PTSD can precede or exacerbate depression, anxiety disorders, suicidality, substance abuse, eating disorders, and psychosis¹. Furthermore, PTSD can precede a range of physical and behavioral indicators, including chronic pain and tobacco use.

There is also evidence from network analysis indicating how symptoms of PTSD may impact other psychiatric symptoms. Network analysis conceptualizes psychopathological states as resulting from causal paths between different symptoms – rather than emerging from an underlying disease state^{2, 3}. For example, the PTSD symptom of nightmares may play a causal role in contributing to sleep disturbance, which in turn leads to concentration deficits and irritability. Numerous studies using network analysis have shown that specific PTSD symptoms can influence problems across other conditions, including depression and anx­iety disorders⁴.

In explaining the role of PTSD as a mediator of the relationship between trauma exposure and onset of other psychiatric disorders, there are several mechanisms that can be considered, and these arguably function in an interactive manner.

One key potential mechanism is the impact of PTSD on the capacity to down-regulate emotional distress. It is well documented that PTSD involves impaired emotion regulation, and it is possible that this impairment predisposes people to develop new psychiatric disorders or worsens others⁵. The capacity to regulate emotions in PTSD can be related to the well-documented deficits in executive functioning⁶. Deficient working memory and attentional capacity can limit the extent to which one can regulate emotions, which can result in greater risk for mental health problems.

Moreover, avoidance is a key symptom of PTSD, and this can trigger a cascade of strategies that can be maladaptive. Avoidance can involve situations or thoughts and memories related to the traumatic experience. This tendency can generalize to more pervasive avoidance of social networks, emotional states, and activities that promote good mental health. This can lead to a worsening of depression, anxiety and other psychiatric conditions.

Another common form of avoidance for people with PTSD is self-medicating with prescription or non-prescription substances to numb the distress that is experienced along with traumatic memories. This behaviour can not only lead to substance abuse, which has been documented in longitudinal studies of PTSD, but also facilitate other psychiatric problems, because issues may not be addressed in a constructive manner. Avoidance tendencies can also result in not seeking help from mental health services, which can impede early intervention or adequate treatment for other psychiatric disorders.

The DSM-5 explicitly recognizes the presence of harmful behaviors in PTSD, including such risk-taking behaviors as dangerous driving, severe alcohol use, and self-harm. These reactions are conceptualized as a result of the extreme arousal and the difficulties in impulse control that can be experienced by people with PTSD⁷. These behaviors can lead to a range of events and habits triggering repetitive cycles of exposure to trauma. This can compound the sensitization that has been reported in PTSD, in which the condition results in neural sensitivity to threats and stressors in one’s environment, such that the person is more reactive to these events.

One of the strongest transdiagnostic predictors of risk for mental health problems is represented by maladaptive or catastrophic appraisals about oneself or the environment⁸. A key feature of PTSD is the tendency to engage in catastrophic appraisals after the traumatic experience, and these appraisals can generalize to many aspects of a person’s life, such as one’s self-esteem, trust in others, fears of negative evaluations, germs, or self-blame. These cognitive tendencies are major risk factors for an array of psychiatric conditions, including anxiety, depression, eating disorders, and obsessive-compulsive disorder. Relatedly, the tendency to ruminate is well documented after trauma, and this habit of repeatedly thinking about negative events is a major risk factor for many psychiatric conditions.

In considering these various mechanisms for how PTSD can moderate other psychiatric problems, it is worth noting that many of the risk factors reviewed here may be present prior to trauma exposure, and in fact predispose the person to developing PTSD. These elements can be intensified as PTSD develops, and then contribute to other psychiatric conditions which have a shared vulnerability. In this context, it is especially worth recognizing the emerging evidence on shared genetic vulnerabilities to a range of psychiatric disorders⁹. In the wake of trauma exposure and PTSD development, gene expression can predispose an individual to develop other psychiatric disorders by means of the shared genetic vulnerability.

Overall, this evidence reflects the interactive multifactorial nature of the processes explaining how PTSD can lead to the onset or worsening of other psychiatric conditions. Understanding how PTSD can impact on other psychological problems is an important area of future research, because it has important treatment implications. Targeting PTSD may have downstream benefits for many problems beyond the specific domain of that disorder.

创伤后应激障碍 (PTSD) 与一系列其他精神障碍的合并症很常见。这种合并症通常归因于创伤后应激障碍和其他疾病之间的重叠症状，或者归因于暴露于创伤经历后可能出现的各种精神疾病。然而，这种合并症也可能是由于 PTSD 可以缓和其他精神症状或疾病的发作或严重程度。这是一个重要的问题，因为它对如何最有效地管理受创伤后可能出现的一系列症状影响的患者具有影响。

我们对 PTSD 如何影响其他疾病的了解依赖于评估 PTSD 和其他状况的纵向研究，并且通常进行交叉滞后或时间序列分析。这种方法使我们能够在以后的评估中确定每种情况对其他疾病的影响程度。综合证据表明，创伤后应激障碍可以先于或加剧抑郁症、焦虑症、自杀、药物滥用、饮食失调和精神病¹。此外，PTSD 可以先于一系列身体和行为指标，包括慢性疼痛和烟草使用。

网络分析也有证据表明 PTSD 的症状可能如何影响其他精神症状。网络分析将精神病理学状态概念化为由不同症状之间的因果路径引起的，而不是从潜在疾病状态^{2、3 中}出现。例如，噩梦的创伤后应激障碍症状可能在导致睡眠障碍方面发挥因果作用，进而导致注意力不集中和易怒。大量使用网络分析的研究表明，特定的 PTSD 症状会影响其他疾病的问题，包括抑郁症和焦虑症⁴。

在解释创伤后应激障碍作为创伤暴露与其他精神疾病发作之间关系的中介的作用时，可以考虑几种机制，并且可以说这些机制以交互方式起作用。

一个关键的潜在机制是 PTSD 对下调情绪困扰能力的影响。有充分的证据表明，创伤后应激障碍涉及情绪调节受损，并且这种损害有可能使人们易患新的精神疾病或使他人恶化⁵。在 PTSD 中调节情绪的能力可能与有据可查的执行功能缺陷有关⁶。工作记忆和注意力不足会限制一个人调节情绪的程度，从而导致更大的心理健康问题风险。

此外，回避是 PTSD 的一个关键症状，这会引发一系列可能不适应的策略。回避可能涉及与创伤经历相关的情况或想法和记忆。这种趋势可以概括为更普遍地避免社交网络、情绪状态和促进良好心理健康的活动。这可能导致抑郁、焦虑和其他精神疾病的恶化。

创伤后应激障碍患者另一种常见的回避方式是使用处方药或非处方药进行自我治疗，以麻木伴随创伤记忆而经历的痛苦。这种行为不仅会导致药物滥用，这已在 PTSD 的纵向研究中得到证明，而且还会促进其他精神问题，因为问题可能无法以建设性的方式解决。回避倾向也可能导致不寻求心理健康服务的帮助，这可能会阻碍对其他精神疾病的早期干预或充分治疗。

The DSM-5 explicitly recognizes the presence of harmful behaviors in PTSD, including such risk-taking behaviors as dangerous driving, severe alcohol use, and self-harm. These reactions are conceptualized as a result of the extreme arousal and the difficulties in impulse control that can be experienced by people with PTSD⁷. These behaviors can lead to a range of events and habits triggering repetitive cycles of exposure to trauma. This can compound the sensitization that has been reported in PTSD, in which the condition results in neural sensitivity to threats and stressors in one’s environment, such that the person is more reactive to these events.

One of the strongest transdiagnostic predictors of risk for mental health problems is represented by maladaptive or catastrophic appraisals about oneself or the environment⁸. A key feature of PTSD is the tendency to engage in catastrophic appraisals after the traumatic experience, and these appraisals can generalize to many aspects of a person’s life, such as one’s self-esteem, trust in others, fears of negative evaluations, germs, or self-blame. These cognitive tendencies are major risk factors for an array of psychiatric conditions, including anxiety, depression, eating disorders, and obsessive-compulsive disorder. Relatedly, the tendency to ruminate is well documented after trauma, and this habit of repeatedly thinking about negative events is a major risk factor for many psychiatric conditions.

In considering these various mechanisms for how PTSD can moderate other psychiatric problems, it is worth noting that many of the risk factors reviewed here may be present prior to trauma exposure, and in fact predispose the person to developing PTSD. These elements can be intensified as PTSD develops, and then contribute to other psychiatric conditions which have a shared vulnerability. In this context, it is especially worth recognizing the emerging evidence on shared genetic vulnerabilities to a range of psychiatric disorders⁹. In the wake of trauma exposure and PTSD development, gene expression can predispose an individual to develop other psychiatric disorders by means of the shared genetic vulnerability.

总体而言，这一证据反映了解释 PTSD 如何导致其他精神疾病发作或恶化的过程的交互多因素性质。了解 PTSD 如何影响其他心理问题是未来研究的一个重要领域，因为它具有重要的治疗意义。针对 PTSD 可能对超出该疾病特定领域的许多问题产生下游益处。