Medical conditions associated with an increased risk of PTSD include cancer, heart attack, and stroke. Intensive-care unit (ICU) hospitalization is also a risk factor for PTSD. Some women experience PTSD from their experiences related to breast cancer and mastectomy.

Sudden, unexpected death of a loved one is the most common traumatic event type reported in cross-national studies. However, the majority of people who experience this type of event will not go on to develop PTSD. An analysis from the WHO World Mental Health Surveys found a 5.2% risk of developing PTSD after learning of the unexpected death of a loved one. Because of the high prevalence of this type of traumatic event, unexpected death of a loved one accounts for approximately 20% of PTSD cases worldwide.

Various factors have been found to be more associated with a diagnosis of AD than other axis I disorders, including:

- younger age

- more identified psychosocial and environmental problems

- increased suicidal behaviour, more likely to be rated as improved by the time of discharge from mental healthcare

- less frequent previous psychiatric history

- shorter length of treatment

Those exposed to repeated trauma are at greater risk, even if that trauma is in the distant past. Age can be a factor due to young children having fewer coping resources; children are also less likely to assess the consequences of a potential stressor.

A stressor is generally an event of a serious, unusual nature that an individual or group of individuals experience. The stressors that cause adjustment disorders may be grossly traumatic or relatively minor, like loss of a girlfriend/boyfriend, a poor report card, or moving to a new neighborhood. It is thought that the more chronic or recurrent the stressor, the more likely it is to produce a disorder. The objective nature of the stressor is of secondary importance. Stressors' most crucial link to their pathogenic potential is their perception by the patient as stressful. The presence of a causal stressor is essential before a diagnosis of adjustment disorder can be made.

There are certain stressors that are more common in different age groups:

Adulthood:

- Marital conflict

- Financial conflict

- Health issues with Oneself/Partner or Dependent children

- Personal tragedy (Death/personal loss)

- Loss of job or unstable employment conditions (e.g. Corporate takeover/redundancy)

Adolescence and childhood:

- Family conflict/parental separation

- School problems/changing schools

- Sexuality issues

- Death/illness/trauma in the family

In a study conducted from 1990 to 1994 on 89 psychiatric outpatient adolescents, 25% had attempted suicide in which 37.5% had misused alcohol, 87.5% displayed aggressive behaviour, 12.5% had learning difficulties, and 87.5% had anxiety symptoms.

Underlying causes may include:

- Han (a Korean culture-related depressive sentiment related to hard life and social unfairness resulting not only from a tragic collective national history, but also from personal traumas)

- prior instances of major depressive disorder

- prior instances of anxiety disorder

- prior instances of adjustment disorder

- prior instances of other somatoform disorders

- repression of feelings of anger/resentment arising from past events

Triggering causes are typically external events, including:

- familial stressors, e.g. spousal infidelity or conflict with in-laws

- witnessing acts/actions/phenomena that conflict with one's own moral and/or ethical principles

The syndrome itself is believed to be the result of the continued repression of feelings of anger without addressing their source. In holistic medicine the containment of anger in hwabyung disturbs the balance of the five bodily elements, resulting in the development of psychosomatic symptoms such as panic, insomnia, and depression after a long period of repressed feelings.

It is possible that hormonal imbalances such as those around the time of menopause may also be an underlying cause of hwabyung in middle-aged women, the most often-diagnosed demographic.

Although more research is needed to determine the multiple pathways to complicated grief disorder, preexisting conditions (such as major depression, PTSD, and sleep disorders) are thought to exacerbate the interruption of the natural healing process.

There are some known predictive characteristics for CGD. An individual is at increased risk for CGD if they are:

- Female

- Pessimistic

- Previously diagnosed with a mood disorder

- Low self-reported social support

- An insecure attachment

- High stress

- A positive caregiving experience and dependency on the deceased

- Have had a early pregnancy loss (miscarriage)

CGD is an atypical grief response, occurring only in a minority of the bereaved population. It is considered more common in those experiencing disasters, violence or the loss of a child.

It has also been found in family members (or friends) of:

- Patients with life-threatening illnesses

- Suicides and homicides

CGD is found to be prevalent cross-culturally in Europe, the Middle East, Africa, and Asia.

According to the DSM IV-TR, the development of the emotional or behavioral symptoms of this diagnosis have to occur within three months of the onset of the identifiable stressor(s). Some emotional signs of adjustment disorder are:

However, the stress-related disturbance does not only exist as an exacerbation of a pre-existing axis I or axis II disorder and cannot be diagnostic as axis 1 disorder.

Suicidal behavior is prominent among people with AD of all ages, and up to one-fifth of adolescent suicide victims may have an adjustment disorder. Bronish and Hecht (1989) found that 70% of a series of patients with AD attempted suicide immediately before their index admission and they remitted faster than a comparison group with major depression. Asnis et al. (1993) found that AD patients report persistent ideation or suicide attempts less frequently than those diagnosed with major depression. According to a study on 82 AD patients at a clinic, Bolu et al. (2012) found that 22 (26.8%) of these patients were admitted due to suicide attempt, consistent with previous findings. In addition, it was found that 15 of these 22 patients chose suicide methods that involved high chances of being saved. Henriksson et al. (2005) states statistically that the stressors are of one-half related to parental issues and one-third in peer issues.

Traumatic grief or complicated mourning are conditions where both trauma and grief coincide. There are conceptual links between trauma and bereavement since loss of a loved one is inherently traumatic. If a traumatic event was life-threatening, but did not result in death, then it is more likely that the survivor will experience post-traumatic stress symptoms. If a person dies, and the survivor was close to the person who died, then it is more likely that symptoms of grief will also develop. When the death is of a loved one, and was sudden or violent, then both symptoms often coincide. This is likely in children exposed to community violence.

For C-PTSD to manifest, the violence would occur under conditions of captivity, loss of control and disempowerment, coinciding with the death of a friend or loved one in life-threatening circumstances. This again is most likely for children and stepchildren who experience prolonged domestic or chronic community violence that ultimately results in the death of friends and loved ones. The phenomenon of the increased risk of violence and death of stepchildren is referred to as the Cinderella effect.

Prevalence of PTSD following normal childbirth (excluding stillbirth or major complications) is estimated to be between 2.8 and 5.6% at 6 weeks postpartum, with rates dropping to 1.5% at 6 months postpartum. Symptoms of PTSD are common following childbirth, with prevalence of 24-30.1% at 6 weeks, dropping to 13.6% at 6 months.

A mental breakdown (also known as a nervous breakdown) is an acute, time-limited mental disorder that manifests primarily as severe stress-induced depression, anxiety, or dissociation in a previously functional individual, to the extent that they are no longer able to function on a day-to-day basis until the disorder is resolved. A nervous breakdown is defined by its temporary nature, and often closely tied to psychological burnout, severe overwork, sleep deprivation, and similar stressors, which may combine to temporarily overwhelm an individual with otherwise sound mental functions.

Hwabyeong or Hwabyung is a Korean somatization disorder, a mental illness which arises when people are unable to confront their anger as a result of conditions which they perceive to be unfair.

Hwabyung is a colloquial and somewhat inaccurate name, as it refers to the etiology of the disorder rather than its symptoms or apparent characteristics. Hwabyung is known as a culture-bound syndrome. The word hwabyung is composed of "hwa" (the Sino-Korean word for "fire" which can also contextually mean "anger") and "byung" (the Sino-Korean word for "syndrome" or "illness"). In South Korea, it may also be called "ulhwabyeong" (), literally "depression anger illness". In one survey, 4.1% of the general population in a rural area in Korea were reported as having hwabyung. Another survey shows that about 35% of Korean workers are affected by this condition at some time.

Birth can be traumatic in different ways. Medical problems can result in interventions that can be frightening. The near death of a mother or baby, heavy bleeding, and emergency operations are examples of situations that can cause psychological trauma. Premature birth may be traumatic.

Emotional difficulties in coping with the pain of childbirth can also cause psychological trauma. Lack of support, or insufficient coping strategies to deal with the pain are examples of situations that can cause psychological trauma. However, even normal birth can be traumatic, and thus PTSD is diagnosed based on symptoms of the mother and not whether or not there were complications.

Additionally, in the process of birth, medical professionals who are there to aid the birthing mother may need to examine and perform procedures in the genital regions.

The following are correlated with PTSD:

- Medical complications before, during, or after childbirth:

- Pregnancy complications

- Emergency C-section

- Instrumental delivery

- Episiotomy

- Severe pain during birth

- Postpartum complications

- Preterm labour

- History of infertility

- Inadequate care during labour

- Social, psychological, and other factors:

- Unwanted pregnancy

- Low socioeconomic status

- Primiparous (first labour)

- Parenting (infant caring) problems

- Social support following childbirth

- Cultural factors

- History of mental health issues

- Other life stressors

The terms "nervous breakdown" and "mental breakdown" have not been formally defined through a medical diagnostic system such as the DSM-5 or ICD-10, and are nearly absent from current scientific literature regarding mental illness. Although "nervous breakdown" is not rigorously defined, surveys of laypersons suggest that the term refers to a specific acute time-limited reactive disorder, involving symptoms such as anxiety or depression, usually precipitated by external stressors. Many health experts today refer to a nervous breakdown as a "modern mental health crisis."

Specific cases are sometimes described as a "breakdown" only after the emotional and physical demands on a person's life are so great as to prevent him or her from performing activities of daily living or, less strictly, only when those demands prevent him/her from performing his/her familial or occupational duties.

Nervous breakdowns are often caused by serious ongoing mental health disorders.

Depersonalization has been described by some as a desirable state, particularly by those that have experienced it under the influence of mood-altering recreational drugs. It is an effect of dissociatives and psychedelics, as well as a possible side effect of caffeine, alcohol, amphetamine, and cannabis. It is a classic withdrawal symptom from many drugs.

Benzodiazepine dependence, which can occur with long-term use of benzodiazepines, can induce chronic depersonalization symptomatology and perceptual disturbances in some people, even in those who are taking a stable daily dosage, and it can also become a protracted feature of the benzodiazepine withdrawal syndrome.

Lieutenant Colonel Dave Grossman, in his book "", suggests that military training artificially creates depersonalization in soldiers, suppressing empathy and making it easier for them to kill other human beings.

Graham Reed (1974) noted that depersonalization occurs in relation to the experience of falling in love.

Emotional dysregulation (ED) is a term used in the mental health community to refer to an emotional response that is poorly modulated, and does not fall within the conventionally accepted range of emotive response.

Possible manifestations of emotional dysregulation include angry outbursts or behavior outbursts such as destroying or throwing objects, aggression towards self or others, and threats to kill oneself. These variations usually occur in seconds to minutes or hours. Emotional dysregulation can lead to behavioral problems and can interfere with a person's social interactions and relationships at home, in school, or at place of employment.

Emotional dysregulation can be associated with an experience of early psychological trauma, brain injury, or chronic maltreatment (such as child abuse, child neglect, or institutional neglect/abuse), and associated disorders such as reactive attachment disorder. Emotional dysregulation may present in people with psychiatric disorders such as attention deficit hyperactivity disorder, bipolar disorder, borderline personality disorder, narcissistic personality disorder, and complex post-traumatic stress disorder. ED is also found among those with autism spectrum disorders. In such cases as borderline personality disorder, hypersensitivity to emotional stimuli causes a slower return to a normal emotional state. This is manifested biologically by deficits in the frontal cortices of the brain.

It is proposed that ameliorating the stress response will allow neurotransmission to return to homeostasis. Anxiolytic medications that act as 5-HT receptor agonists (in particular, 5-HT1A) together with CRH and/or cortisol antagonists (which are implicated in the stress response) are hypothesized to be an appropriate method of achieving this therapeutic response. Psychological interventions can also help to raise the threshold for stress and thereby restore the stress response to normal.

Depersonalization is also a direct symptom of Lyme disease as well as other tick-borne diseases. If depersonalization is suspected a blood-test is required in search of anti-bodies.

Rape trauma syndrome (RTS) is the psychological trauma experienced by a rape victim that includes disruptions to normal physical, emotional, cognitive, and interpersonal behavior. The theory was first described by psychiatrist Ann Wolbert Burgess and sociologist Lynda Lytle Holmstrom in 1974.

RTS is a cluster of psychological and physical signs, symptoms and reactions common to most rape victims immediately following and for months or years after a rape. While most research into RTS has focused on female victims, sexually abused males (whether by male or female perpetrators) also exhibit RTS symptoms. RTS paved the way for consideration of complex post-traumatic stress disorder, which can more accurately describe the consequences of serious, protracted trauma than posttraumatic stress disorder alone. The symptoms of RTS and post-traumatic stress syndrome overlap. As might be expected, a person who has been raped will generally experience high levels of distress immediately afterward. These feelings may subside over time for some people; however, individually each syndrome can have long devastating effects on rape victims and some victims will continue to experience some form of psychological distress for months or years. It has also been found that rape survivors are at high risk for developing substance use disorders, major depression, generalized anxiety disorder, obsessive-compulsive disorder, and eating disorders.

RTS identifies three stages of psychological trauma a rape survivor goes through: the acute stage, the outer adjustment stage, and the renormalization stage.

C-PTSD may share some symptoms with both PTSD and borderline personality disorder.

It may help to understand the intersection of attachment theory with C-PTSD and BPD if one reads the following opinion of Bessel A. van der Kolk together with an understanding drawn from a description of BPD:

Uncontrollable disruptions or distortions of attachment bonds precede the development of post-traumatic stress syndromes. People seek increased attachment in the face of danger. Adults, as well as children, may develop strong emotional ties with people who intermittently harass, beat, and, threaten them. The persistence of these attachment bonds leads to confusion of pain and love. Trauma can be repeated on behavioural, emotional, physiologic, and neuroendocrinologic levels. Repetition on these different levels causes a large variety of individual and social suffering.

However, C-PTSD and BPD have been found by researchers to be completely distinctive disorders with incredibly different features – notably, C-PTSD is not a personality disorder – those who suffer do not fear abandonment, do not have unstable patterns of relations – rather they withdraw and they do not struggle with lack of empathy.

There are distinct and notably large differences between Borderline and C-PTSD and while there are some similarities – predominantly in terms of issues with attachment (though this plays out in completely different ways) and trouble regulating strong emotional effect (often feel pain vividly), the disorders are completely different in nature – especially considering that C-PTSD is always a response to trauma rather than a personality disorder. In addition, C-PTSD is not a personality disorder – rather it is often a case of survival reactions to trauma becoming a fundamental aspect of the personality, "in response to" living with a personality disordered individual.

"While the individuals in the BPD reported many of the symptoms of PTSD and CPTSD, the BPD class was clearly distinct in its endorsement of symptoms unique to BPD. The RR ratios presented in Table 5 revealed that the following symptoms were highly indicative of placement in the BPD rather than the CPTSD class: (1) frantic efforts to avoid real or imagined abandonment, (2) unstable and intense interpersonal relationships characterized by alternating between extremes of idealization and devaluation, (3) markedly and persistently unstable self-image or sense of self, and (4) impulsiveness. Given the gravity of suicidal and self-injurious behaviors, it is important to note that there were also marked differences in the presence of suicidal and self-injurious behaviors with approximately 50% of individuals in the BPD class reporting this symptom but much fewer and an equivalent number doing so in the CPSD and PTSD classes (14.3 and 16.7%, respectively). The only BPD symptom that individuals in the BPD class did not differ from the CPTSD class was chronic feelings of emptiness, suggesting that in this sample, this symptom is not specific to either BPD or CPTSD and does not discriminate between them."

"Overall, the findings indicate that there are several ways in which Complex PTSD and BPD differ, consistent with the proposed diagnostic formulation of CPTSD. BPD is characterized by fears of abandonment, unstable sense of self, unstable relationships with others, and impulsive and self-harming behaviors. In contrast, in CPTSD as in PTSD, there was little endorsement of items related to instability in self-representation or relationships. Self-concept is likely to be consistently negative and relational difficulties concern mostly avoidance of relationships and sense of alienation."

In addition 25% of those diagnosed with BPD have no known history of childhood neglect or abuse and individuals are six times as likely to develop BPD if they have a relative who was so diagnosed compared to those who do not. One conclusion is that there is a genetic predisposition to BPD unrelated to trauma. Researchers conducting a longitudinal investigation of identical twins found that "genetic factors play a major role in individual differences of borderline personality disorder features in Western society." A 2014 study published in European Journal of Psychotraumatology was able to compare and contrast C-PTSD, PTSD, Borderline Personality Disorder and found that it could distinguish between individual cases of each and when it was co-morbid, arguing for a case of separate diagnoses for each. BPD may be confused with C-PTSD by some without proper knowledge of the two conditions because those with BPD also tend to suffer from PTSD or to have some history of trauma.

In "Trauma and Recovery," Herman expresses the additional concern that patients who suffer from C-PTSD frequently risk being misunderstood as inherently 'dependent', 'masochistic', or 'self-defeating', comparing this attitude to the historical misdiagnosis of female hysteria. However, those who develop C-PTSD do so as a result of the intensity of the trauma bond – in which someone becomes tightly biolo-chemically bound to someone who abuses them (also known as Stockholm Syndrome – seen in cases of kidnapping in which a person falls in love with their captors) and the responses they learned to survive, navigate and deal with the abuse they suffered then become automatic responses, imbedded in their personality over the years of trauma – a normal reaction to an abnormal situation.

Epidemiological data are limited, but reactive attachment disorder appears to be very uncommon. The prevalence of RAD is unclear but it is probably quite rare, other than in populations of children being reared in the most extreme, deprived settings such as some orphanages. There is little systematically gathered epidemiologic information on RAD. A cohort study of 211 Copenhagen children to the age of 18 months found a prevalence of 0.9%.

Attachment disorders tend to occur in a definable set of contexts such as within some types of institutions, in the presence of repeated changes of primary caregiver or of extremely neglectful identifiable primary caregivers who show persistent disregard for the child's basic attachment needs, but not all children raised in these conditions develop an attachment disorder. Studies undertaken on children from Eastern European orphanages from the mid-1990s showed significantly higher levels of both forms of RAD and of insecure patterns of attachment in the institutionalized children, regardless of how long they had been there. It would appear that children in institutions like these are unable to form selective attachments to their caregivers. The difference between the institutionalized children and the control group had lessened in the follow-up study three years later, although the institutionalized children continued to show significantly higher levels of indiscriminate friendliness. However, even among children raised in the most deprived institutional conditions the majority did not show symptoms of this disorder.

A 2002 study of children in residential nurseries in Bucharest, in which the DAI was used, challenged the current DSM and ICD conceptualizations of disordered attachment and showed that inhibited and disinhibited disorders could coexist in the same child.

There are two studies on the incidence of RAD relating to high risk and maltreated children in the U.S. Both used ICD, DSM and the DAI. The first, in 2004, reported that children from the maltreatment sample were significantly more likely to meet criteria for one or more attachment disorders than children from the other groups, however this was mainly the proposed new classification of disrupted attachment disorder rather than the DSM or ICD classified RAD or DAD. The second study, also in 2004, attempted to ascertain the prevalence of RAD and whether it could be reliably identified in "maltreated" rather than "neglected" toddlers. Of the 94 maltreated toddlers in foster care, 35% were identified as having ICD RAD and 22% as having ICD DAD, and 38% fulfilled the DSM criteria for RAD. This study found that RAD could be reliably identified and also that the inhibited and disinhibited forms were not independent. However, there are some methodological concerns with this study. A number of the children identified as fulfilling the criteria for RAD did in fact have a preferred attachment figure.

It has been suggested by some within the field of attachment therapy that RAD may be quite prevalent because severe child maltreatment, which is known to increase risk for RAD, is prevalent and because children who are severely abused may exhibit behaviors similar to RAD behaviors. The APSAC Taskforce consider this inference to be flawed and questionable. Severely abused children may exhibit similar behaviors to RAD behaviors but there are several far more common and demonstrably treatable diagnoses which may better account for these difficulties. Further, many children experience severe maltreatment and do not develop clinical disorders. Resilience is a common and normal human characteristic. RAD does not underlie all or even most of the behavioral and emotional problems seen in foster children, adoptive children, or children who are maltreated and rates of child abuse and/or neglect or problem behaviors are not a benchmark for estimates of RAD.

There are few data on comorbid conditions, but there are some conditions that arise in the same circumstances in which RAD arises, such as institutionalization or maltreatment. These are principally developmental delays and language disorders associated with neglect. Conduct disorders, oppositional defiant disorder, anxiety disorders, post-traumatic stress disorder and social phobia share many symptoms and are often comorbid with or confused with RAD. Attachment disorder behaviors amongst institutionalized children are correlated with attentional and conduct problems and cognitive levels but nonetheless appear to index a distinct set of symptoms and behaviors.

This proposed subtype is characterized by depression occurring as a consequence of psychic, somatic or external stressors. Praag theorizes that if the individual's stress threshold is insufficient or overly sensitive, a prolonged stress response via the HPA axis can trigger anxiety followed by significant lowering of mood, the mechanisms of which act to reenforce each other, keeping the sufferer in a perpetual state of stress arousal, coupled with dysphoria; and that this occurs as a result of the stress response inhibiting the normal expression of neurotransmitters associated with wellbeing and pleasure. He proposes that sufferers may experience panic attacks, depersonalization and other psychic and somatic symptoms common to both anxiety and depression disorders.

According to van Praag, in Anxiety/Aggression-Driven Depression "...dysregulation of anxiety and/or aggression are primordial and mood lowering is a derivative phenomenon."

Although increasing numbers of childhood mental health problems are being attributed to genetic defects, reactive attachment disorder is by definition based on a problematic history of care and social relationships. Abuse can occur alongside the required factors, but on its own does not explain attachment disorder. It has been suggested that types of temperament, or constitutional response to the environment, may make some individuals susceptible to the stress of unpredictable or hostile relationships with caregivers in the early years. In the absence of available and responsive caregivers it appears that some children are particularly vulnerable to developing attachment disorders.

There is as yet no explanation for why similar abnormal parenting may produce the two distinct forms of the disorder, inhibited and disinhibited. The issue of temperament and its influence on the development of attachment disorders has yet to be resolved. RAD has never been reported in the absence of serious environmental adversity yet outcomes for children raised in the same environment vary widely.

In discussing the neurobiological basis for attachment and trauma symptoms in a seven-year twin study, it has been suggested that the roots of various forms of psychopathology, including RAD, Borderline Personality Disorder (BPD), and post-traumatic stress disorder (PTSD), can be found in disturbances in affect regulation. The subsequent development of higher-order self-regulation is jeopardized and the formation of internal models is affected. Consequently, the "templates" in the mind that drive organized behavior in relationships may be impacted. The potential for "re-regulation" (modulation of emotional responses to within the normal range) in the presence of "corrective" experiences (normative caregiving) seems possible.

Vicarious trauma affects workers being 'witnesses' to their clients' trauma. It is more likely to occur in situations where trauma related work is the norm rather than the exception. Listening with empathy to the clients generates feeling, and 'seeing oneself' in clients' trauma may compound the risk for developing trauma symptoms. May also result if we are witness to situations that happen in the course of our work (e.g. violence in the workplace, reviewing violent video tapes, etc.). Risk increases with exposure and with the absence of seeking protective factors and pre-preparation of preventive strategies.

The cause of dog separation anxiety is unknown, but may be triggered by:

- a traumatic event

- a change in routine

- major life change (e.g., new home, new baby, death of a family member, abandonment to a shelter)

- extreme attachment or dependency on the owner