Understanding Important Concepts of SDT

To understand how SDT can be used as a theory to integrate common factors, it is important to be familiar with the basic concepts of SDT, for which there is strong meta-analytical evidence (Ryan et al., 2022).

The Organismic Dialectic and Basic Psychological Needs

SDT postulates that humans have evolved to be growth-oriented organisms (Deci & Ryan, 2000). They are naturally inclined toward integration of their experiences and extrinsic regulations into a unified sense of self, the engagement of interesting activities (intrinsic motivation) and the integration of themselves into social structures (integrative tendencies; Deci & Ryan, 2000). SDT further proposes that these tendencies for integration require ongoing nutriments and supports of basic psychological human needs (Deci & Ryan, 2000). If these nutriments are supplied by the (social) environment or constructed by the individual from inner resources and the basic needs are satisfied, humans will function effectively and experience well-being and vitality (Deci & Ryan, 2000). Therefore, basic need satisfaction can also be the aim of integrative tendencies (Ryan & Deci, 2017) but does not have to be (Deci & Ryan, 2000). The basic needs are the need for autonomy, competence, and relatedness (Deci & Ryan, 2000).

Autonomy plays the most important role for adaptive functioning in SDT (Ryan & Deci, 2017). At a phenomenological level, the need for autonomy refers to the necessity of experiencing a sense of volition and integrity (Deci & Ryan, 2000, p. 253; Ryan et al., 2016; p. 386). Autonomy at a structural level is the tendency of humans toward self-regulation of action and coherence (Deci & Ryan, 2000, p. 253; Ryan et al., 2016; p. 386). When autonomous, an individual’s actions are self-organized regarding their inner and outer circumstances instead of being prompted by nonintegrated inner processes or environmental pressures (Deci & Ryan, 2000, p. 254). Autonomous actions are informed by an individuals’ permanent values and are congruent with their sense of self (Ryan et al., 2016). According to SDT, the attentional state of awareness facilitates this autonomous self-regulation of actions and is foundational to autonomy (Deci et al., 2015; Ryan et al., 2021). In a state of awareness, people are more receptive to internal and external experiences, which helps them to focus on self-endorsed values (Elphinstone et al., 2021). This makes them better able to select behaviors that are aligned with their values and to align their responses “to the pressures the world” with their personal values (integration; Elphinstone et al., 2021; Ryan et al., 2021). This fosters more autonomous motivation (Elphinstone et al., 2021).

Competence is the need to experience mastery or self-efficacy and to make a meaningful impact on one’s environment (Deci & Ryan, 2000). It is the tendency to seek optimal challenges and to develop skills (Deci & Ryan, 2000). The need for relatedness refers to the experience of warmth, reciprocal care, and belongingness (Ryan et al., 2016). It is the need to feel connected with others (Ryan & Deci, 2000) and to experience “a sense of being integral to social organizations” (Ryan & Deci, 2017; p.11).

Basic Needs and Goal-Directed Intentional Behavior (Motivation)

The existence of the three basic needs can explain why some kinds of goal pursuit are associated with greater well-being than others. Goal pursuit is associated with greater well-being if the content of the goals consists of intrinsic aspirations (e.g., personal growth and not extrinsic aspirations like attaining fame) and if the process by which goals are pursued is autonomous/self-determined and not controlled (Deci & Ryan, 2000). This is because basic needs are more likely to be satisfied when pursuing goals in this way (Deci & Ryan, 2000, pp. 247–248). The most extreme kind of controlled behavior is external regulation as one type of extrinsic motivation (regulatory style). In external regulation, a person’s behavior is controlled by external contingencies such as tangible rewards (Deci & Ryan, 2000). In contrast, the prototype of autonomous activity is intrinsically motivated behavior (Deci & Ryan, 2000). Intrinsically motivated behaviors are activities that individuals engage in naturally “when they feel free to follow their inner interests” (Deci & Ryan, 2000, p. 234). Besides controlled and autonomous behaviors that involve regulatory processes, there are also states in which people lack any intention to act. In such states of amotivation, people are not able to regulate themselves. This may occur when they lack a sense of efficacy or control with respect to a desired outcome (Deci & Ryan, 2000, p.237).

The Internalization of Extrinsic Regulations

SDT argues that individuals seek to transform external regulations (like socially sanctioned requests) into personally endorsed values so that they can be autonomous by enacting them (Deci & Ryan, 2000). This internalization process is aimed at building a coherent sense of self and becoming more intrapsychically and socially integrated. When this process functions well, the individual will identify with the importance of social regulations and accept them as their own, which is called integration (fullest form of internalization; Deci & Ryan, 2000). However, when the internalization process is impeded, external regulations may remain external or only be partially internalized (Deci & Ryan, 2000). In this latter case, introjects or unintegrated identifications are formed which are not fully self-determined (Deci & Ryan, 2000). By introjects, Ryan and Deci (2008) mean “partial internalizations” that manifest as intrapersonal pressures and rewards and result in individuals experiencing no real choice. Hence, in introjected motivation the individual’s behavior is controlled by contingent consequences that are administered by the individual to themselves and not by others. In identification, the individual has come to accept the value of a behavior and more fully accepts it as their own. Although the behavior is more autonomous, it is still extrinsically motivated (somewhat controlled) as it is still instrumental and not simply conducted out of mere enjoyment (Deci & Ryan, 2000).

Lack of Life Satisfaction, Ill-Being and Their Causes

According to SDT, a persistent lack of basic need satisfaction or even a thwarting of basic needs (i.e. the active frustration of basic needs, such as rejection) in the person’s immediate situation or developmental history leads to a lack of integration and growth and thus to a diminished experience of mental health and to ill-being (Deci & Ryan, 2000; Ryan et al., 2016). People who are thwarted of their basic needs can withdraw from others, behave antisocially, compartmentalize rather than integrate psychological structures and display controlled motivation or even amotivation (Deci & Ryan, 2000, p. 237). They may develop need substitutes or compensatory motives (e.g., strong focus on extrinsic values like money; Deci & Ryan, 2000; Ryan & Deci, 2017). Social environments that impede satisfaction of the need for autonomy promote controlled motivation whereas environments that also undermine satisfaction of the needs for competence and relatedness promote amotivation (Deci & Ryan, 2000, p. 251). A state of need deprivation or lack of well-being can exacerbate the thwarting of needs and thus increase the experience of ill-being (Deci & Ryan, 2000). A lack of basic need satisfaction or need thwarting in everyday context has not only external (e.g., social environment like family) but also internal reasons like inter-individual differences in regulatory styles and biological vulnerabilities (Deci & Ryan, 2000, p. 232).

Specific Psychopathology and Their Etiology

Developmental need thwarting (in interaction with genetic and biological factors) can lead to autonomy disturbances, that is, the disruption of integrated self-regulation (Ryan et al., 2016; Ryan & Deci, 2017). Ryan et al. (2016) argue that autonomy disturbances are central to different kinds of psychopathology. Autonomy can be disrupted in different ways, and the impairments in competence and relatedness experience can vary (Ryan & Deci, 2017).

In internally controlling pathologies (e.g., depression, eating disorders, obsessive pathologies), the individual’s motivation to act is highly controlled (Ryan et al., 2016). These pathologies are characterized by regulation through introjects (Ryan et al., 2016). Social norms and values have been only partially internalized (they are not part of the integrated self) and exert ongoing pressure on the individual (Ryan & Deci, 2017). Parental thwarting of autonomy and relatedness are central factors in these disorders (Ryan et al., 2016).

Externalizing pathologies (e.g., antisocial personality, conduct disorders) are characterized by the relative absence of self-regulation, internalization, emotion regulation, and capacities for relatedness (Ryan et al., 2016; Ryan & Deci, 2017). In these pathologies, attachment to caregivers and the readiness to internalize their values/social norms has not taken place (Ryan et al., 2016).

Disorders associated with fragmented self-functioning (e.g., borderline personality, dissociative identity disorders) are characterized by serious disturbances of the self with little integrated functioning and capacities for internalization (Ryan et al., 2016). Individuals may lack internal regulatory processes to modulate emotions like anxiety or they show impulsivity (Ryan et al., 2016). They may further lack a stable identity and capacities for reflective awareness (Ryan et al., 2016). In these disorders, active intrusive thwarting of autonomy and relatedness needs throughout development plays an important role (Ryan et al., 2016).

Other severe mental illnesses characterized by fragmented self-functioning, such as schizophrenia (Hamm et al., 2017), may not be the result of developmental need thwarting, but are still associated with a lack of need satisfaction and autonomy dysfunction (Ryan & Deci, 2017; Thai et al., 2024). For example, Breitborde et al. (2012) showed that individuals with first-episode psychosis reported lower levels of need satisfaction than individuals without psychosis, and that the need for relatedness was most frequently associated with well-being in individuals with first-episode psychosis.

Understanding Common Processes of Change in Psychotherapy through SDT

We now show how the described SDT-concepts can be used to coherently organize and integrate the common factors (see Fig. 1). According to SDT, the described lack of well-being and the specific psychological disorders (also severe mental illness like schizophrenia) can be improved by basic psychological need satisfaction in psychotherapy and by increasing the patient’s (self-regulatory) skill to satisfy these needs in their natural environments (Breitborde et al., 2012; Ryan et al., 2016). Therefore, at least according to our SDT-based reasoning here, different types of psychotherapy may be equally effective because they all provide the patient with experiences of autonomy, competence, and relatedness and increases their self-regulatory skills to achieve and maintain need-satisfaction and integration of experiences into a unified self. When patients become aware of their basic needs and these are satisfied in the immediate (therapeutic) situation and in the long term in their everyday contexts, they no longer have to direct their energy towards need substitutes (e.g. extrinsic life goals) and show controlled motivational orientations that they had developed in the past due to basic need thwarting (Ryan & Deci, 2008). Empirical research has shown that basic psychological need satisfaction (i.e. autonomy, competence, relatedness) is related to positive therapy outcomes (e.g., Quitasol et al., 2018; Zuroff et al., 2007).

Fig. 1

Common Factors Model of Psychopathology, Change, and Treatment Based on Self-Determination Theory (SDT). Note. Only the SDT processes that are primarily or most strongly addressed by the common techniques are shown; the relationships between the common change processes are also not shown (e.g. increased autonomous regulation leads to higher satisfaction of competence and relationship needs)

We argue that the various common processes proposed in the common factors literature reflect all instances of basic need satisfaction and increased self-regulatory skills as defined by SDT and may therefore be effective. In particular, we refer to the following common factors: the patient gaining awareness and insight (McAleavey & Castonguay, 2014), the patient learning to (self)-regulate their emotions, behavior, and thoughts (Lambert & Ogles, 2004), the patient having positive and self-efficacy expectations (Frank & Frank, 1991), and the patient experiencing the mitigation of their social isolation (Frank & Frank, 1991; Wampold & Budge, 2012). From the SDT perspective, these common factors each reflect a process of increased basic need satisfaction and self-regulation leading to higher well-being.

(A) Awareness/Insight and Regulation of Thoughts, Emotions, and Behavior may Reflect Autonomous Regulation, Integration and Autonomy Need Satisfaction

According to SDT, the development of (autonomous) self-regulatory processes plays an important role for growth and well-being (Deci & Ryan, 2000). In autonomous self-regulation, an individual’s actions are informed by the individuals’ values and preferences and are congruent with their sense of self (Ryan et al., 2016). Through internalization/integration, external regulations (like social pressures) can be transformed into personally endorsed values so that they become autonomously regulated (Deci & Ryan, 2000). According to SDT, psychotherapy promotes the patient’s autonomous self-regulation of their actions by helping them to understand their experiences and take responsibility for new behaviors (Ryan & Deci, 2008). For example, in emotion regulation, the patient learns to better control, express and validate their emotions (Brown, 2015; Tschacher et al., 2014). According to SDT, better (i.e. more autonomous) emotion regulation means emotional integration. In emotional internalization/integration, the patient has differentiated awareness of their emotional states and has “the capacity to use this sensitivity and awareness in the volitional regulation of action” (Ryan et al., 2016, p. 407). In other words, emotions, when “openly received” and accessed by the self, provide crucial information that guides the individual in setting goals and adjusting them toward the fulfillment of their basic psychological needs (Ryan et al., 2016, p. 407). Emotional integration is characterized by emotions neither controlling the individual (being overwhelmed by affect) nor the individual controlling (e.g., ignoring, suppressing) their emotions (Ryan et al., 2016). The same logic can be applied to thought regulation and controlling thoughts: when thoughts are “openly received” and accessed by the self in psychotherapy, they provide important information to set self-endorsed goals that align with basic need satisfaction, reflecting autonomous regulation. It becomes clear that SDT offers a thorough explanation why the common factors of better emotion, thought, and behavior regulation are important common change processes: they reflect increased autonomous regulation and autonomy need satisfaction.

From the above reasoning it also becomes clear that the common factor insight/awareness supports the described autonomous self-regulation of emotions, thoughts and behavior. In a state of awareness people have better access to internal and external (social) environments, their emotions, introjects, and suppressed experiences which facilitates integration of the latter so that they become more aligned with endorsed values and motivation becomes more autonomous (Elphinstone et al., 2021; Ryan & Deci, 2008). The common factors literature has also described initial awareness, on which insight (the forming of new connections/a new understanding; Connolly Gibbons et al., 2007) relies, as condition through which the individual “recognizes his external and internal environment” (Trevisi et al.,