Behavioral crises in the course of borderline personality disorder (BPD) and post traumatic stress disorder (PTSD) consist of intrusive rehearsals of old entrapment in danger, dissociative states with unstoppable irrational urges, hallucinations, mood lability and impulsivity. They are notoriously costly in utilization of acute services [1–5]. This study investigates a clinical intervention that may offer quick reduction of symptoms to reduce those costs. The experimental intervention is part of the Cape Cod Model of psychotherapy .
Behavioral crises in chronic post traumatic disorders
There is a domain of study that aspires to demonstrate that complex PTSD and BPD are related. These studies attribute to both a hypothesized post traumatic mechanism of disorder resulting from dependency in a relationship with mistrusted caretakers, individuals or institutions [7, 8]. Those caretakers controlled the dependent's means to ascertain and correct the caretakers' trustworthiness as well as the dependent's means to leave the relationship. Differently from simple PTSD, survivors of that particular trauma recreate semblances of dependency in later relationships, semblances of others' betrayal and of their own powerlessness.
The hypothesized shared mechanism of disorder for complex PTSD and BPD has not been investigated empirically. Still, their similarity in personality development and the phenomenology of their crises is evident. Guilt, shame, loss of faith in the benevolence of others, hopelessness, mistrust and avoidance of primary relationships are personality attributes of persons with complex PTSD [9–16], a 'unique trademark' that distinguishes it from simple PTSD . As these attributes were found also in BPD, some authors subsumed them in concepts of post traumatic personality disorder [15, 18]. The description resembles the diagnostic category of the International Classification of Diseases, 10th edition (ICD-10)  called 'enduring personality changes after catastrophic experience', such as lengthy captivity in adult life.
The crises of both complex PTSD and BPD are characterized by the sufferer's instigation of others to behave in ways that resemble entrapment by mistrusted caretakers . That activity is commonly recognized in the clinical literature as 'repetition compulsion', with various explanations [21–27]. In complex PTSD and BPD, the classic symptoms of post traumatic disorder, vigilance, numbness and flashbacks, happen in the course of repetition compulsion. For the purposes of this study, the term 'behavioral crisis' is used only for this complex presentation. A typical description of it is given in the next paragraph, as it was provided to clinicians for recognition of prospective subjects, before diagnostic screening.
Typical behavioral crises are a composite of many unresolved semblances of dependency in mistrusted relationships from one crisis to the next. The person's judgments about blame for the entrapment become ever more uncertain. For example, a man who hears hallucinatory voices saying 'you are a loser' cannot be sure if that judgment was inflicted on him by his father who used to lock him in the closet or by his mother who never brought him the food and water that she promised. The voice sometimes sounds like an admired teacher's whose class he never dared attend. His recollection shifts with endless doubts about who wanted him in the role of loser, including himself. Sometimes he doubts the factuality of a particular event altogether. The means of testing others' commitment grow ever stranger and costlier, in terms of sacrifices, demands and acts of atonement. He self-mutilates, binges on food or sex, menaces for trivial wants and against trivial dangers. The force and repetitiveness of these activities blind him to his own intervening needs and to others' feelings and reasons. Afterwards, he remembers all that blundering very inexactly.
Efficacy of treatment
Studies of the efficacy of treatments for behavioral crises are reviewed here in aggregate, for both BPD and PTSD. The distinction between simple and complex PTSD had not been made yet at the time of these studies and reviews.
Studies of outcomes with long-term pharmacotherapy for these disorders pertain mainly to mitigation of behavioral crises (for example, of irrational and shifting moods, impulsivity and psychotic symptoms). In summary, reviews of those studies find the evidence sparse and inconclusive, with trends in support of modest improvement of each symptom for selected drugs [28–40]. Professional practice guidelines emphasize the symptomatic nature of relief with medication [36, 41–43]. As such, medication is a useful adjunct to psychotherapy that, in turn, may repair the mechanism of crises, thereby making medication unnecessary. Some authors explain the limitations of pharmacotherapy by the nature of BPD and complex PTSD as disorders of social learning [30, 44].
For long-term psychotherapy as well, studies of outcomes with particular schools [45–51], reviews of studies [33, 52–64] and practice guidelines [36, 42, 43] agree that crises become fewer, with less acting out and intensity. Patients consistently become less angry, labile and impulsive; they self-mutilate less and make fewer suicide gestures.
In recognition of how difficult it is to engage patients in new insights during crises, much of psychotherapy in the intervals promotes the value of self-policing, self-soothing and welcoming others' help with the same. Nonetheless, several programs had similar results with an abbreviated, intense course of various psychotherapies, tailored for crisis times [65–74].
Reparative and symptomatic psychotherapy
Beyond reviewing the efficacy of long-term psychotherapy for reduction of crises, the theory underlying the experimental intervention makes it relevant to review the efficacy also for deep structural reparation of the mechanism of disorder. The theory of the Cape Cod Model claims that the experimental intervention achieves reparation of that mechanism, in measurable increments from one application to the next. This study introduces pilot instruments to begin measuring the patient's experience of modification of the putative mechanism.
Remarkably, the efficacy for reduction of behavioral crises cited in the preceding section is similar among the different schools of psychotherapy [47, 58, 75]. For the early stages of therapy, the different schools borrow among them short-term techniques that mitigate burdensome symptoms. By design, all therapies included in these reviews advise patients to forego expectations for intimacy in unfulfilled old relationships or in new ones until after in-therapy lessons accumulate. They all promise gradual deep correction of the patients' response to danger in intimate relationships, though via sharply different interventions. So far, the evidence suggests success from the techniques that the different schools share in early phases. Results for later phases, however, which they each promise to obtain differently, have not been demonstrated yet. Outcome studies show consistently that patients become more compliant with treatment, mingle with others more comfortably and take better care of themselves [24, 47, 61, 62]. However, the evidence is less consistent for improvement of symptoms in the intervals between behavioral crises, that is, anxiety and depression, dysphoria, paranoia and dysfunctional beliefs [24, 47, 58, 61, 62]. There is no significant improvement for a residual cluster of symptoms, a 'subsyndrome'  of hopelessness, emptiness and fear of intimacy.
With these concerns in mind, Benjamin and Linehan proposed to measure therapy's efficacy in degrees of reparation of the 'core dysfunction' in complex post traumatic syndromes [76–78]. Reparation should show as competence in intimate relationships, having 'a life worth living', beyond the passage 'from loud to quiet desperation'. They envisioned a research program that will identify the true core dysfunction as hypothesized by competing theories and measure its gradual correction. Otherwise 'what is a "symptom" to one [author] may be the mechanism controlling a disorder to another' . Benjamin nominates 'underlying destructive attachments' as the core dysfunction to investigate. A concept akin to Benjamin's, that of regressive social learning, guides the Cape Cod Model of treatment during and between crises .
The Cape Cod Model
According to the Cape Cod Model, the irrational and unstoppable activity of behavioral crises is the sufferer's way of coping with perceived entrapment in a current treacherous relationship. The entrapment, whether true or false, consists of the perception of betrayal which the person cannot ascertain one way or the other. The sufferer can neither become certain enough of the other's trustworthiness to recommit to the current relationship, nor can he become certain enough to move on, confident to ascertain betrayal in later relationships.
The mechanism of disorder is in the sufferers' regressive method of testing the other's fidelity to promises and expectations, commonly recognized as repetition compulsion . Regressive testing elicits more semblances of betrayal, which compounds their sense of their own entrapment. Each round of testing renders them more uncertain than before. This circular, self-defeating activity replicates the method that survivors of dependency in mistrusted relationships learned as the way to test their caretakers' trustworthiness.
The Cape Cod Model explains the course of chronic post traumatic disorder over the lifetime in terms of a social breakdown syndrome. Cumulatively, from one crisis to the next, survivors of entrapment in failed caretaking relationships mislearn that love is indecipherable and, therefore, a dangerous gamble. They grow simultaneously more desperate for intimacy and more apprehensive of it. In response to the survivors' wasteful, repetitive testing, others also become tentative about offering opportunities for intimacy to them. The social breakdown often takes hold despite psychotherapy because patients have reasons to keep their regressive experiments private from their therapist and they are hardly aware of them as the source of behavioral crises. To observers, crises appear to emerge in response to incidental reminders of old trauma, even trivial ones. Over time, patients mislearn from their private experiments faster than they make progress in therapy with analysis of the transference and of scenarios of old betrayals.
The crisis intervention of the Cape Cod Model aims for quick resolution by offering immediate, rudimentary proof that trustworthiness is testable, directly in the troubled relationship or in an opportune relationship beyond this loss. Clinicians propose ways to make intimacy safe, ways which patients cannot envision on their own, to replace repetition compulsion, the mechanism of disorder and the source of all symptoms. From resolution of one crisis to the next, the experimental intervention cumulatively improves the sufferer's vulnerability in future relationships.
Outside crises, psychotherapy with the Cape Cod Model is designed to anticipate crises and abort the social breakdown syndrome. From the beginning of therapy, clinicians join patients in seizing opportunities for increments of intimacy in life-defining relationships. The patients' goal is to test others' trustworthiness effectively, in order to let go of repetition compulsion.