Dialectical behaviour therapy (DBT) is a well-established treatment for borderline personality disorder (BPD). It seems to be efficacious and this also holds for chronically depressed older adults and individuals with eating disorders. DBT decreases problem behaviours in BPD (e.g. self-injurious behaviour; suicide attempts; suicidal ideation; hopelessness; bulimic behaviour; depression).

DBT focuses on the balance between acceptance (i.e. no complete acceptance of behaviour due to the seriousness but no blame) and change (i.e. no complete focus on change as this can be seen as critique but no apathy). The dialectic refers to the process by which a behaviour, phenomenon or argument is transformed. It consists of three stages:

1. Thesis
   This includes the initial proposition or statement (i.e. thesis)
2. Antithesis
   This includes the negation of the beginning phenomenon and this involves an antithesis.
3. Negation of the negation
   This includes the synthesis of the thesis and the antithesis.

Tension develops between the thesis and the antithesis and the synthesis between the two is the new thesis. The process is then repeated. DBT thus treats the whole patients and does not focus on a discrete disorder (e.g. it targets the whole emotion system). It recognizes that all elements of the system are interrelated.

The biosocial theory of BPD states that the transaction between a biological tendency toward emotional vulnerability and an invalidation rearing environment produces a dysregulation of the patient’s emotional system. A synthesis of these two processes need to be found (i.e. dialectic). Emotional vulnerability refers to a biologically mediated predisposition for heightened sensitivity and reactivity to emotionally evocative stimuli and a delayed return to baseline emotional arousal. The invalidating environment is characterized by punishing (1), ignoring (2) or trivializing (3) the individual’s communication of thoughts and emotions as well as self-initiated behaviours. The intense emotional reactions elicit invalidating behaviour and this elicits further emotional dysregulation.

Individuals with BPD often experience disruption of their cognitive, emotional and behavioural systems when emotionally aroused. Many of the behaviours associated with BPD are seen as inevitable consequences of dysregulated emotions or as maladaptive methods of altering emotional experiences.

DBT views reductions in emotion dysregulation and increases in behavioural skills as the primary controlling variables underlying treatment change. An excessive focus on change in treatment may mirror the invalidating environment. However, acceptance may not express the severity of the symptoms. Therefore, a synthesis needs to be found.

Mindfulness in DBT is related to the quality of awareness that an individual contributes to the present experiences. It refers to a state or quality of awareness which involves keeping one’s consciousness alive to the present reality. It includes letting go of attachments and becoming one with the current experience. Mindfulness in DBT includes the skills observing (1), describing (2) and participating fully in one’s actions and experiences in a non-judgemental and one-mindful manner (3). It also includes radically accepting a current situation, thought, emotion or experience and maintaining a stance of willingness to enter into life with awakeness and effectiveness. The goal of the mindfulness skills is to help patients increase their conscious control over attentional processes (1), achieve a wise integration of emotional and rational thinking (2) and experience a sense of unity and oneness with themselves and others (3).

There are several potential mechanisms of change in mindfulness:

• Behavioural exposure and learning new responses
  Mindfulness involves learning to control the focus of attention rather than the object of attention. Mindfulness may work through non-reinforced exposure to previously avoided emotions, thoughts and sensations (i.e. non-judgemental awareness in the absence of dire consequences). Behavioural exposure may include the active learning of alternative responses to stimuli that elicit unwanted internal experiences. Extinction may depend on context and mindfulness may lead to an internal context that maintains the extinction of unwanted responses and promotes the acquisition of new response.
• Emotion regulation
  Mindfulness may influence the experience of emotions. It may reverse emotion-linked response tendencies and associated cognitive appraisals. Mindfulness may change automatic response tendencies when the patient observes, describes and participates in emotional experiences without acting on them. This also leads people to change associated thoughts, images or memories. Mindfulness may thus change the meaning of the event by changing the response tendency.
• Reducing literal belief in rules
  Literal beliefs in verbal rules (e.g. “giving a speech will lead to me being laughed at”) leads the individual to experience thoughts, feelings and situations as dangerous and to evaluate certain thoughts as bad. Mindfulness teaches individuals to observe a thought without believing it is literally true. This maximizes sensitivity to current contingencies in the environment. People with BPD often have a very negative sense of self which is maintained by literal belief in negative self-judgements and mindfulness may create a new sense of self by making sure that individuals do not literally believe in these rules.
• Attentional control
  Mindfulness may aid individuals with BPD in disengaging attention from emotional stimuli. Controlling attentional focus may also improve emotion regulation.

Validation refers to being awake to, accurately reflecting and conveying acceptance of the patient’s behaviour, thoughts, or feelings. It is one of the core acceptance strategies in DBT and involves interacting with the patient in a genuine manner. It is used to balance the change-based strategies (1), strengthen or reinforce clinical progress (2), model self-validation (3), provide feedback (4) and enhance the therapeutic alliance (5). There are six levels of validation:

• Active listening and awakeness to and interest in the patient.
• Accurate reflecting of the patient’s feelings, thoughts or behaviours.
• Articulating unverbalized feelings or thoughts.
• Expressing that the patient’s dysfunctional behaviour is logical in view of past learning history.
• Expressing that the patient’s behaviour is expected given the current context.
• Acting in a manner that is genuine.

There are several mechanisms of change in validation:

1. Increasing the stability of self-views
   A stable self-view provides people with a crucial source of coherence. People maintain a stable self-view as long as they receive steady, self-verifying feedback from others. Validation increases the development of a coherent sense of self.
2. Reducing emotional arousal and enhancing learning
   People tend to experience negative emotional arousal when goals are blocked and heightened arousal interferes with cognition and task performance. Validating the patient’s self-views may undo this process and decrease the patient’s emotional arousal which can enhance learning of new behaviours.
3. Increasing motivation
   Validation may enhance the patient’s motivation to remain in therapy. Validation may provide a self-confirmatory environment and this may enhance motivation.
4. Modelling and contingency management
   Validation may reinforce behavioural progress (e.g. therapist is more genuine when using a particularly skilful behaviour in session). Validation may thus serve as a reinforcer. It may also provide a modelling experience as the patient learns ways in which to validate one’s own reactions or behaviours through modelling.

The patient monitors behaviours that are life-threatening (1), therapy-interfering (2) and quality-of-life interfering (3). A chain analysis is conducted to determine the antecedent events that increased the likelihood that the behaviour would occur (1), the prompting events (2) and consequences (3). It focuses on moment-to-moment changes in external conditions, emotions, thoughts, behaviours and consequences. It is a detailed evaluation of a single chain o behaviour. There are several potential mechanisms of change in targeting and chain analysis:

1. Aversive contingencies
   The chain analysis may function as punisher for engaging in target behaviours (e.g. the patient learns that engaging in these behaviours will lead to a lengthy discussion of the behaviour and the surrounding context).
2. Exposure and response prevention
   DBT focuses on the role of the emotion system in behavioural dysfunction (e.g. suicide attempt is an attempt to regulate intense, unwanted emotions). The focus on chain analysis is on components of emotion regulation that support or maintain these behaviours. Discussing the emotional responses and their eliciting stimuli promotes non-reinforced exposure to emotions and reduce shame which makes the response less likely to happen again. Non-reinforced exposure may weaken the association between the behaviour and the emotional response of shame, thus facilitating problem solving.
3. Enhancing episodic memory
   The detail of chain analysis may enhance stimulus discrimination and episodic memory. BPD is associate with a tendency to overly generalized memory for personally relevant events. Elaborate discussion of the events that led to dysfunctional behaviour may increase the likelihood that patients will recognize future patterns and implement skilful behaviour as needed.
4. In vivo learning of skilful behaviour
   The dialectical synthesis of assessment and intervention during the chain analysis may promote in vivo learning. Chain analysis is integrated with many different skills (e.g. solution generation) and this provides the patient with the opportunity to learn these skills.

Telephone consultation is the primary intervention used to generalize behavioural skills from the therapy session to the client’s natural environment. It allows the patient to call the therapist and this may aid generalization of skills. Re-emergence of extinguished responses may occur in new contexts because of a failure to retrieve the memory of extinction. Telephone calls may serve as a cue for the retrieval of extinction memories from therapy sessions, leading to generalization of skills to new environments. The therapist’s presence in the patient’s natural environment may prevent the renewal of dysfunctional behaviour and elicit skilful behaviour.

Opposite action involves determining that an emotion is unjustified or interferes with behaviour (1), being exposed to emotionally evocative stimuli (2), blocking the behaviour prompted by the emotion’s action urge (3) and substituting a behaviour that is inconsistent with the action tendency compelled by the emotion (4). Opposite action aims to target emotion dysregulation and targets a broad range of emotions. There are several potential mechanisms of change of opposite action:

1. Exposure and response prevention
   It includes exposure to emotionally evocative stimulus while engaging in behaviour that is incompatible with the action tendency prompted by the emotions. This exposure (i.e. incompatible response) could lead to response prevention by demonstrating that the response tendency was unjustified.
2. Broadening the patient’s repertoire and learning of new responses
   Opposite action may lead to learning of new responses, especially in all-the-way opposite actions.
3. Cognitive modification
   Opposite action may broaden the patient’s cognitive responses to emotional experiences (i.e. cognitive response may change by having a different response and a different emotional response).

Dialectical strategies involve balancing irreverent and reciprocal communication and acceptance-based and change-based interventions. It involves magnifying tension (1), working for a synthesis or antithesis (2), using metaphors (3), varying in speed and intensity in interacting with the patient (4) and using movement fluidly in session to keep the patient awake and off balance (5). There are several potential mechanisms of change:

1. Enhanced orienting responses
   The nature of dialectical strategies requires patients to remain awake and attentive to what is happening. This may thus influence the orienting response (i.e. the response to a novel stimulus). It may thus increase attention, cognitive processing and learning.
2. In vivo learning and modelling
   Dialectical interventions may provide learning experiences that directly prompt the patient to practice new behaviours. The therapist can also model dialectical statements or thinking leading to the patient to internalize this.

The patient may punish effective treatment and reinforces iatrogenic behaviour. This may be especially likely when the therapist and patient express polarized opinions on an aspect of treatment. Polarization can be reduced through dialectics (i.e. synthesisation). The therapist consultation team refers to a small community of providers who agree to adopt a dialectical philosophy. The focus of the discussions is on the therapist’s behaviour to maintain efficacy of the treatment.