Psychotherapy is the use of psychological methods, particularly when based on regular personal interaction , to help a person change and overcome problems in desired ways. Psychotherapy aims to improve an individual's well-being and mental health , to resolve or mitigate troublesome behaviors, beliefs, compulsions, thoughts, or emotions, and to improve relationships and social skills . Certain psychotherapies are considered evidence-based for treating some diagnosed mental disorders .
There are over a thousand different psychotherapies, some being minor variations, while others are based on very different conceptions of psychology, ethics (how to live) or techniques. Most involve one-to-one sessions, between client and therapist, but some are conducted with groups , including families . Psychotherapists may be mental health professionals such as psychiatrists or psychologists, or come from a variety of other backgrounds, and depending on the jurisdiction may be legally regulated, voluntarily regulated or unregulated (and the term itself may be protected or not).
The term psychotherapy is derived from Ancient Greek psyche ( ψυχή meaning "breath; spirit; soul") and therapeia ( θεραπεία "healing; medical treatment"). The Oxford English Dictionary defines it now as "The treatment of disorders of the mind or personality by psychological methods..." 
The American Psychological Association adopted a resolution on the effectiveness of psychotherapy in 2012 based on a definition developed by John C. Norcross : "Psychotherapy is the informed and intentional application of clinical methods and interpersonal stances derived from established psychological principles for the purpose of assisting people to modify their behaviors, cognitions, emotions, and/or other personal characteristics in directions that the participants deem desirable".   Influential editions of a work by psychiatrist Jerome Frank defined psychotherapy as a healing relationship using socially authorized methods in a series of contacts primarily involving words, acts and rituals—regarded as forms of persuasion and rhetoric . 
Some definitions of counseling overlap with psychotherapy (particularly non-directive client-centered approaches), or counseling may refer to guidance for everyday problems in specific areas, typically for shorter durations with a less medical focus.  Somatotherapy refers to the use of physical methods as treatments, and sociotherapy to the use of a person's social environment to effect therapeutic change.  Psychotherapy may address spirituality as part of mental life, and some forms are derived from spiritual philosophies, but practices based on treating the spiritual as a separate dimension would not necessarily be considered psychotherapy. 
Historically psychotherapy has sometimes meant "interpretative" (i.e. Freudian ) methods, by contrast with other methods to treat psychiatric disorders such as behavior modification.
Psychotherapy is often dubbed "talking therapy", particularly for a general audience,  though not all forms of psychotherapy rely on verbal communication .  Children or adults who do not engage in verbal communication (or not in the usual way) are not excluded from psychotherapy; indeed some types are designed for such cases.
Psychotherapists may be mental health professionals , professionals from other backgrounds trained in a specific therapy, or in some cases non-professionals. Psychiatrists are first trained as physicians. As such, they may prescribe prescription medication . Specialist psychiatric training begins after medical school in psychiatric residencies. Clinical psychologists have a specialist doctoral degrees in psychology with clinical and research components. Clinical social workers may have specialized training and practical experience in psychotherapy. Many of the wide variety of training programs and institutional settings are multi-professional. In most countries professionals doing specialized psychotherapeutic work also require a program of continuing education after the basic degree.
As sensitive and deeply personal topics are often discussed during psychotherapy, therapists are expected, and usually legally bound, to respect client or patient confidentiality. The critical importance of client confidentiality —and the limited circumstances in which it may need to be broken for the protection of clients or others—is enshrined in the regulatory psychotherapeutic organizations' codes of ethical practice. 
As of 2015 there is still much variation between European countries. A few have no regulation of the practice or no protection of the title. Some have a system of voluntary registration with independent professional organisations, while others attempt to restrict it to mental health professionals with years of additional state-certified training. Which titles are "protected" also varies.  The European Association for Psychotherapy set up after the 1990 Strasbourg Declaration on Psychotherapy attempts to set independent pan-European standards. 
In Germany, the practice of psychotherapy for adults is restricted to qualified psychologists and physicians (including psychiatrists) who have completed five years of specialist practical training and certification in psychotherapy. Social workers may complete the specialist training for child and teenage clients.  Similarly in Italy, the practice of psychotherapy is restricted to graduates in psychology or medicine who have completed four years of recognised specialist training.   Sweden has a similar restriction on the title "psychotherapist", which may only be used by professionals who have gone through a post-graduate training in psychotherapy and then applied for a licence, issued by the National Board of Health and Welfare . 
French legislation restricts the use of the title "psychotherapist" to professionals on the National Register of Psychotherapists,  which requires a training in clinical psychopathology and a period of internship which is only open to physicians or titulars of a master's degree in psychology or psychoanalysis.
Austria and Switzerland (2011) have laws that recognize multidifunctional-disciplinary approaches.
In the United Kingdom , psychotherapy is voluntarily regulated. National registers for psychotherapists and counsellors are maintained by three main umbrella bodies : The United Kingdom Council for Psychotherapy (UKCP), The British Association for Counselling and Psychotherapy (BACP) and The British Psychoanalytic Council .  There are many smaller professional bodies and associations such as the Association of Child Psychotherapists (ACP)  and the British Association of Psychotherapists (BAP).  The government and Health and Care Professions Council considered mandatory legal registration but decided that it was best left to professional bodies to regulate themselves, so the Professional Standards Authority for Health and Social Care (PSA) launched an Accredited Voluntary Registers scheme.     
In some states, counselors or therapists must be licensed to use certain words and titles on self-identification or advertising: in some other states, the restrictions on practice are more closely associated with the charging of fees. Licensing and regulation are performed by the various states. Presentation of practice as licensed, but without such a license, is generally illegal.  Without a license, for example a practitioner cannot bill insurance companies.  Information about state licensure is provided by the American Psychological Association
In addition to state laws, the American Psychological Association enacts “Ethical Principles” for its members. The American Board of Professional Psychology examines and certifies “psychologists who demonstrate competence in approved specialty areas in professional psychology.” 
In the Western tradition , by the 19th century a moral treatment movement (then meaning morale or mental) developed based on non-invasive non-restraint therapeutic methods.  Another influential movement was started by Franz Mesmer (1734–1815) and his student Armand-Marie-Jacques de Chastenet, Marquis of Puységur (1751–1825). Called Mesmerism or animal magnetism, it would have a strong influence on the rise of dynamic psychology and psychiatry as well as theories about hypnosis .   In 1853 Walter Cooper Dendy introduced the term "psycho-therapeia" regarding how physicians might influence the mental states of sufferers and thus their bodily ailments, for example by creating opposing emotions to promote mental balance.   Daniel Hack Tuke cited the term and wrote about "psycho-therapeutics" in 1872, in which he also proposed making a science of animal magnetism .   Hippolyte Bernheim and colleagues in the " Nancy School" developed the concept of "psychotherapy" in the sense of using the mind to heal the body through hypnotism , yet further.  Charles Lloyd Tuckey's 1889 work, Psycho-therapeutics, or Treatment by Hypnotism and Suggestion popularized the work of the Nancy School in English.   Also in 1889 a clinic used the word in its title for the first time, when Frederik van Eeden and Albert Willem in Amsterdam renamed theirs "Clinique de Psycho-thérapeutique Suggestive" after visiting Nancy.  During this time, travelling stage hypnosis became popular, and such activities added to the scientific controversies around the use of hypnosis in medicine.  Also in 1892, at the second congress of experimental psychology, van Eeden attempted to take the credit for the term psychotherapy and to distance the term from hypnosis.  In 1896, the German journal Zeitschrift für Hypnotismus, Suggestionstherapie, Suggestionslehre und verwandte psychologische Forschungen changed its name to Zeitschrift für Hypnotismus, Psychotherapie sowie andere psychophysiologische und psychopathologische Forschungen, which is probably the first journal to use the term.  Thus psychotherapy initially meant "the treatment of disease by psychic or hypnotic influence, or by suggestion" 
Sigmund Freud visited the Nancy School and his early neurological practice involved the use of hypnotism. However following the work of his mentor Josef Breuer —in particular a case where symptoms appeared partially resolved by what the patient, Bertha Pappenheim , dubbed a " talking cure "—Freud began focusing on conditions that appeared to have psychological causes originating in childhood experiences and the unconscious mind . He went on to develop techniques such as free association , dream interpretation , transference and analysis of the id, ego and superego . His popular reputation as father of psychotherapy was established by his use of the distinct term " psychoanalysis ", tied to an overarching system of theories and methods, and by the effective work of his followers in rewriting history.  Many theorists, including Alfred Adler , Carl Jung , Karen Horney , Anna Freud , Otto Rank , Erik Erikson , Melanie Klein and Heinz Kohut , built upon Freud's fundamental ideas and often developed their own systems of psychotherapy. These were all later categorized as psychodynamic , meaning anything that involved the psyche 's conscious / unconscious influence on external relationships and the self. Sessions tended to number into the hundreds over several years.
Behaviorism developed in the 1920s, and behavior modification as a therapy became popularized in the 1950s and 1960s. Notable contributors were Joseph Wolpe in South Africa, M.B. Shipiro and Hans Eysenck  in Britain, and John B. Watson and B.F. Skinner in the United States. Behavioral therapy approaches relied on principles of operant conditioning , classical conditioning and social learning theory to bring about therapeutic change in observable symptoms. The approach became commonly used for phobias , as well as other disorders.
Some therapeutic approaches developed out of the European school of existential philosophy . Concerned mainly with the individual's ability to develop and preserve a sense of meaning and purpose throughout life, major contributors to the field (e.g., Irvin Yalom , Rollo May ) and Europe ( Viktor Frankl , Ludwig Binswanger , Medard Boss , R.D.Laing , Emmy van Deurzen ) attempted to create therapies sensitive to common "life crises" springing from the essential bleakness of human self-awareness, previously accessible only through the complex writings of existential philosophers (e.g., Søren Kierkegaard , Jean-Paul Sartre , Gabriel Marcel , Martin Heidegger , Friedrich Nietzsche ). The uniqueness of the patient-therapist relationship thus also forms a vehicle for therapeutic inquiry. A related body of thought in psychotherapy started in the 1950s with Carl Rogers . Based also on the works of Abraham Maslow and his hierarchy of human needs , Rogers brought person-centered psychotherapy into mainstream focus. The primary requirement was that the client be in receipt of three core "conditions" from his counselor or therapist: unconditional positive regard, sometimes described as "prizing" the client's humanity; congruence [authenticity/genuineness/transparency]; and empathic understanding . This type of interaction was thought to enable clients to fully experience and express themselves, and thus develop according to their innate potential. Others developed the approach, like Fritz and Laura Perls in the creation of Gestalt therapy , as well as Marshall Rosenberg, founder of Nonviolent Communication , and Eric Berne , founder of transactional analysis . Later these fields of psychotherapy would become what is known as humanistic psychotherapy today. Self-help groups and books became widespread.
During the 1950s, Albert Ellis originated rational emotive behavior therapy (REBT). Independently a few years later, psychiatrist Aaron T. Beck developed a form of psychotherapy known as cognitive therapy . Both of these included relatively short, structured and present-focused techniques aimed at identifying and changing a person's beliefs, appraisals and reaction-patterns, by contrast with the more long-lasting insight-based approach of psychodynamic or humanistic therapies. Beck's approach used primarily the socratic method , and links have been drawn between ancient stoic philosophy and these cognitive therapies.
Cognitive and behavioral therapy approaches were increasingly combined and grouped under the umbrella term cognitive behavioral therapy (CBT) in the 1970s. Many approaches within CBT are oriented towards active/directive yet collaborative empiricism (a form of reality-testing), assessing and modifying core beliefs and dysfunctional schemas. These approaches gained widespread acceptance as a primary treatment for numerous disorders. A "third wave" of cognitive and behavioral therapies developed, including acceptance and commitment therapy and dialectical behavior therapy , which expanded the concepts to other disorders and/or added novel components and mindfulness exercises. Counseling methods developed, including solution-focused therapy and systemic coaching .
Postmodern psychotherapies such as narrative therapy and coherence therapy did not impose definitions of mental health and illness, but rather saw the goal of therapy as something constructed by the client and therapist in a social context. Systemic therapy also developed, which focuses on family and group dynamics—and transpersonal psychology , which focuses on the spiritual facet of human experience. Other orientations developed in the last three decades include feminist therapy , brief therapy , somatic psychology , expressive therapy , applied positive psychology and the human givens approach. A survey of over 2,500 US therapists in 2006 revealed the most utilized models of therapy and the ten most influential therapists of the previous quarter-century. 
There are hundreds of psychotherapy approaches or schools of thought. By 1980 there were more than 250;  by 1996 more than 450;  and at the start of the 21st century there were over a thousand different named psychotherapies—some being minor variations while others are based on very different conceptions of psychology, ethics (how to live) or technique.   In practice therapy is often not of one pure type but draws from a number of perspectives and schools—known as an integrative or eclectic approach.   The importance of the therapeutic relationship , also known as therapeutic alliance, between client and therapist is often regarded as crucial to psychotherapy. Common factors theory addresses this and other core aspects thought to be responsible for effective psychotherapy.
Therapy may address specific forms of diagnosable mental illness , or everyday problems in managing or maintaining interpersonal relationships or meeting personal goals. A course of therapy may happen before, during or after pharmacotherapy (e.g. taking psychiatric medication ).
Psychotherapies are categorized in several different ways. A distinction can be made between those based on a medical model and those based on a humanistic model . In the medical model the client is seen as unwell and the therapist employs their skill to help the client back to health. The extensive use of the DSM-IV , the diagnostic and statistical manual of mental disorders in the United States, is an example of a medically exclusive model. The humanistic or non-medical model in contrast strives to depathologise the human condition. The therapist attempts to create a relational environment conducive to experiential learning and help build the client's confidence in their own natural process resulting in a deeper understanding of themselves. The therapist may see themselves as a facilitator/helper.
Therapies are sometimes classified according to their duration; a small number of sessions over a few weeks or months may be classed as brief therapy (or short-term therapy), others where regular sessions take place for years may be classed as long-term.
Some practitioners distinguish between more "uncovering" (or " depth ") approaches and more "supportive" psychotherapy. Uncovering psychotherapy emphasizes facilitating the client's insight into the roots of their difficulties. The best-known example is classical psychoanalysis. Supportive psychotherapy by contrast stresses strengthening the client's coping mechanisms and often providing encouragement and advice, as well as reality-testing and limit-setting where necessary. Depending on the client's issues and situation, a more supportive or more uncovering approach may be optimal. 
Most forms of psychotherapy use spoken conversation . Some also use various other forms of communication such as the written word, artwork , drama , narrative story or music. Psychotherapy with children and their parents often involves play , dramatization (i.e. role-play), and drawing, with a co-constructed narrative from these non-verbal and displaced modes of interacting. 
There are also different formats for delivering some therapies, as well as the usual face to face: for example via telephone or via online interaction . There have also been developments in computer-assisted therapy, such as virtual reality therapy for behavioral exposure, multimedia programs to each cognitive techniques, and handheld devices for improved monitoring or putting ideas into practice.  
These psychotherapies, also known as " experiential ", are based on humanistic psychology and emerged in reaction to both behaviorism and psychoanalysis, being dubbed the "third force". They are primarily concerned with the human development and needs of the individual, with an emphasis on subjective meaning, a rejection of determinism , and a concern for positive growth rather than pathology . Some posit an inherent human capacity to maximize potential, "the self-actualizing tendency"; the task of therapy is to create a relational environment where this tendency might flourish. Humanistic psychology can in turn be rooted in existentialism —the belief that human beings can only find meaning by creating it. This is the goal of existential therapy . Existential therapy is in turn philosophically associated with phenomenology .
Gestalt therapy , originally called "concentration therapy", is an existential/experiential form that facilitates awareness in the various contexts of life, by moving from talking about relatively remote situations to action and direct current experience. Derived from various influences, including an overhaul of psychoanalysis, it stands on top of essentially four load-bearing theoretical walls: phenomenological method , dialogical relationship, field-theoretical strategies, and experimental freedom.
A briefer form of humanistic therapy is the human givens approach, introduced in 1998/9.  It is a solution-focused intervention based on identifying emotional needs—such as for security, autonomy and social connection—and using various educational and psychological methods to help people meet those needs more fully or appropriately.    
Insight-oriented psychotherapies focus on revealing or interpreting unconscious processes. Most commonly referring to psychodynamic therapy , of which psychoanalysis is the oldest and most intensive form, these applications of depth psychology encourage the verbalization of all the patient's thoughts, including free associations , fantasies, and dreams, from which the analyst formulates the nature of the past and present unconscious conflicts which are causing the patient's symptoms and character problems.
There are four main schools of psychoanalysis, which all influenced psychodynamic theory:  Freudian, Ego psychology , Object relations theory and Glen Gabbard . and Self psychology . Techniques for analytic group therapy have also developed.
Behavior therapies use behavioral techniques, including applied behavior analysis (also known as behavior modification ), to change maladaptive patterns of behavior to improve emotional responses, cognitions, and interactions with others. Functional analytic psychotherapy is one form of this approach. By nature, behavioral therapies are empirical (data-driven), contextual (focused on the environment and context), functional (interested in the effect or consequence a behavior ultimately has), probabilistic (viewing behavior as statistically predictable), monistic (rejecting mind-body dualism and treating the person as a unit), and relational (analyzing bidirectional interactions). 
Cognitive therapy focuses directly on changing the thoughts, in order to improve the emotions and behaviors.
Cognitive behavioral therapy attempts to combine the above two approaches, focused on the construction and re-construction of people's cognitions , emotions and behaviors . Generally in CBT, the therapist, through a wide array of modalities, helps clients assess, recognize and deal with problematic and dysfunctional ways of thinking, emoting and behaving.
A "third wave" reflected an influence of Eastern philosophy in clinical psychology , incorporating principles such as meditation into interventions such as mindfulness-based cognitive therapy , acceptance and commitment therapy and dialectical behavior therapy . 
Interpersonal psychotherapy (IPT) is a relatively brief form of psychotherapy (deriving from both CBT and psychodynamic approaches) that has been increasingly studied and endorsed by guidelines for some conditions. It focuses on the links between mood and social circumstances, helping to build social skills and social support.  It aims to foster adaptation to current interpersonal roles and situations.
Systemic therapy seeks to address people not just individually, as is often the focus of other forms of therapy, but in relationship, dealing with the interactions of groups, their patterns and dynamics (includes family therapy & marriage counseling ). Community psychology is a type of systemic psychology.
The term group therapy was first used around 1920 by Jacob L. Moreno , whose main contribution was the development of psychodrama , in which groups were used as both cast and audience for the exploration of individual problems by reenactment under the direction of the leader. The more analytic and exploratory use of groups in both hospital and out-patient settings was pioneered by a few European psychoanalysts who emigrated to the USA, such as Paul Schilder , who treated severely neurotic and mildly psychotic out-patients in small groups at Bellevue Hospital, New York. The power of groups was most influentially demonstrated in Britain during the Second World War, when several psychoanalysts and psychiatrists proved the value of group methods for officer selection in the War Office Selection Boards. A chance to run an Army psychiatric unit on group lines was then given to several of these pioneers, notably Wilfred Bion and Rickman, followed by S. H. Foulkes , Main, and Bridger. The Northfield Hospital in Birmingham gave its name to what came to be called the two "Northfield Experiments", which provided the impetus for the development since the war of both social therapy, that is, the therapeutic community movement, and the use of small groups for the treatment of neurotic and personality disorders. Today group therapy is used in clinical settings and in private practice settings. 
Expressive therapy is any form of therapy that utilizes artistic expression as its core means of treating clients. Expressive therapists use the different disciplines of the creative arts as therapeutic interventions. This includes the modalities dance therapy , drama therapy , art therapy , music therapy , writing therapy , among others. Expressive therapists believe that often the most effective way of treating a client is through the expression of imagination in a creative work and integrating and processing what issues are raised in the act.
Also known as post-structuralist or constructivist . Narrative therapy gives attention to each person's "dominant story" by means of therapeutic conversations, which also may involve exploring unhelpful ideas and how they came to prominence. Possible social and cultural influences may be explored if the client deems it helpful. Coherence therapy posits multiple levels of mental constructs that create symptoms as a way to strive for self-protection or self-realization. Feminist therapy does not accept that there is one single or correct way of looking at reality and therefore is considered a postmodernist approach. 
Transpersonal psychology addresses the client in the context of a spiritual understanding of consciousness. Positive psychotherapy (PPT) (since 1968) is a method in the field of humanistic and psychodynamic psychotherapy and is based on a positive image of humans, with a health-promoting, resource-oriented and conflict-centered approach.
Hypnotherapy is undertaken while a subject is in a state of hypnosis . Hypnotherapy is often applied in order to modify a subject's behavior, emotional content, and attitudes, as well as a wide range of conditions including: dysfunctional habits,      anxiety,  stress-related illness,    pain management,   and personal development.  
Body psychotherapy , part of the field of somatic psychology , focuses on the link between the mind and the body and tries to access deeper levels of the psyche through greater awareness of the physical body and emotions . There are various body-oriented approaches, such as Reichian ( Wilhelm Reich ) character-analytic vegetotherapy and orgonomy; neo-Reichian bioenergetic analysis ; Somatic Experiencing ; integrative body psychotherapy ; Ron Kurtz's Hakomi psychotherapy; sensorimotor psychotherapy ; Biosynthesis psychotherapy; and Biodynamic psychotherapy. These approaches are not to be confused with body work or body-therapies that seek to improve primarily physical health through direct work (touch and manipulation) on the body, rather than through directly psychological methods.
Some non-Western indigenous therapies have been developed. In African countries this includes harmony restoration therapy, meseron therapy and systemic therapies based on the Ubuntu philosophy .   
Integrative psychotherapy is an attempt to combine ideas and strategies from more than one theoretical approach. These approaches include mixing core beliefs and combining proven techniques. Forms of integrative psychotherapy include multimodal therapy , the transtheoretical model , cyclical psychodynamics, systematic treatment selection, cognitive analytic therapy , Internal Family Systems Model , multitheoretical psychotherapy and conceptual interaction. In practice, most experienced psychotherapists develop their own integrative approach over time.
Counseling and psychotherapy must be adapted to meet the developmental needs of children. It is generally held to be one part of an effective strategy for some purposes and not for others.  These are four purposes that are generally considered inappropriate or pointless reasons for placing a child in psychotherapy:
- To determine why a child originally began misbehaving,
- To improve the child's self-esteem ,
- To make up for inconsistent parenting, and
- To make the child capable of coping with a parent's drug addiction, interpersonal relationships, or other serious dysfunction 
In addition to therapy for the child, or even instead of it, children may benefit if their parents speak to a therapist, take parenting classes, attend grief counseling , or take other actions to resolve stressful situations that affect the child. Parent management training is a highly effective form of psychotherapy that teaches parents skills to reduce their child's behavior problems.
Many counseling preparation programs include courses in human development . Since children often do not have the ability to articulate thoughts and feelings, counselors will use a variety of media such as crayons, paint, clay, puppets, bibliocounseling (books), toys, board games, et cetera. The use of play therapy is often rooted in psychodynamic theory , but other approaches such as Solution Focused Brief Counseling may also employ the use of play in counseling. In many cases the counselor may prefer to work with the care taker of the child, especially if the child is younger than age four. Yet, by doing so, the counselor risks the perpetuation of maladaptive interactive patterns and the adverse effects on development that have already been affected on the child's end of the relationship.  Therefore, contemporary thinking on working with this young age group has leaned towards working with parent and child simultaneously within the interaction, as well as individually as needed.  
How to assess
One issue with trials is what to use as a placebo treatment group or non-treatment control group . Often this is patients on a waiting list, or people receiving some kind of regular non-specific contact or support. One issue is the best way to match the use of inert tablets or sham treatments in placebo-controlled studies in pharmaceutical trials. Several interpretations and differing assumptions and language remain.  Another issue is the attempt to standardize and manualize therapies and link them to specific symptoms of diagnostic categories, making them more amenable to research. Some report that this may reduce efficacy or gloss over individual needs. Finagy and Roth's opinion is that the benefits of the evidence-based approach outweighs the difficulties. 
Many psychotherapists believe that the nuances of psychotherapy cannot be captured by questionnaire-style observation, and prefer to rely on their own clinical experiences and conceptual arguments to support the type of treatment they practice. Psychodynamic therapists in particular have opposed evidence-based approaches as not appropriate to their methods or assumptions, though some have increasingly accepted the challenge. 
One line of research consistently finds that supposedly different forms of psychotherapy show similar effectiveness—historically dubbed the Dodo bird verdict because all win. Further analyses seek to identify the factors that the psychotherapies have in common that seem to account for this, known as common factors theory ; for example the quality of the therapeutic relationship, interpretation of problem, and the confrontation of painful emotions.    
The Helsinki Psychotherapy Study was one of several large long-term clinical trials of psychotherapies that have taken place. Anxious and depressed patients in two short-term therapies (solution-focused and brief psychodynamic) improved faster, but after five years long-term psychotherapy and psychoanalysis gave greater benefits. Several patient and therapist factors appear to predict suitability for different psychotherapies. 
Mechanisms of change
Different therapeutic approaches may be associated with particular theories about what needs to change in a person for a successful therapeutic outcome.
In general, processes of emotional arousal and memory have long been held to play an important role. One theory combining these aspects proposes that permanent change occurs to the extent that the neuropsychological mechanism of memory reconsolidation is triggered and is able to incorporate new emotional experiences.    
Adherence to a course of psychotherapy—continuing to attend sessions or complete tasks—is a major issue.
The dropout level—early termination—ranges from around 30% to 60%, depending partly on how it is defined. The range is lower for research settings for various reasons, such as the selection of clients and how they are inducted. Early termination is associated on average with various demographic and clinical characteristics of clients, therapists and treatment interactions.   The high level of dropout has raised some criticism about the relevance and efficacy of psychotherapy. 
Most psychologists use between-session tasks in their general therapy work, and cognitive behavioral therapies in particular use and see them as an "active ingredient". It is not clear how often clients do not complete them, but it is thought to be a pervasive phenomenon. 
From the other side, the adherence of therapists to therapy protocols and techniques—known as "treatment integrity"—has also been studied, with complex mixed results. 
Research on adverse effects of psychotherapy has been limited for various reasons, yet they may be expected to occur in 5% to 20% of patients. Problems include deterioration of symptoms or developing new symptoms, strains in other relationships, and dependency on the therapist. Some techniques or therapists may carry more risks than others, and some client characteristics may make them more vulnerable. Side-effects from properly conducted therapy should be distinguished from harms caused by malpractice. 
Some are skeptical of the healing power of psychotherapeutic relationships.  Some dismiss psychotherapy altogether in the sense of a scientific discipline requiring professional practitioners, instead favoring biomedical treatments. Others have pointed out ways in which the values and techniques of therapists can be harmful as well as helpful to clients (or indirectly to other people in a client's life). 
Many resources available to a person experiencing emotional distress—the friendly support of friends, peers, family members, clergy contacts, personal reading, healthy exercise, research, and independent coping—all present considerable value. Critics note that humans have been dealing with crises, navigating severe social problems and finding solutions to life problems long before the advent of psychotherapy.  Of course, it may well be something in the patient that does not develop these "natural" supports that requires therapy.
On the other hand, some argue psychotherapy is under-utilized and under-researched by contemporary psychiatry despite offering more promise than stagnant medication development. In 2015 the US National Institute of Mental Health is allocating only 5.4% of its budget to new clinical trials of psychotherapies (medication trials are largely funded by pharmaceutical companies ), despite plentiful evidence they can work and that patients are more likely to prefer them. 
Some suggest that successful therapeutic relationships, based on true acceptance of the client as a human being without contingency, require a theological assumption, an ontological acceptance of God.  
Further critiques have emerged from feminist, constructionist and discursive sources. Key to these is the issue of power . In this regard there is a concern that clients are persuaded—both inside and outside the consulting room—to understand themselves and their difficulties in ways that are consistent with therapeutic ideas. This means that alternative ideas (e.g., feminist, economic, spiritual) are sometimes implicitly undermined. Critics suggest that we idealize the situation when we think of therapy only as a helping relationship—arguing instead that it is fundamentally a political practice, in that some cultural ideas and practices are supported while others are undermined or disqualified, and that while it is seldom intended, the therapist-client relationship always participates in society's power relations and political dynamics. A noted academic who espoused this criticism was Michel Foucault .