The word "psychotherapy" stems from two Greek words: psyche (soul) and therapein (to treat). Even though the first mentions on the treatment of mental diseases could be found as early as in prehistoric times in the form of shamanic practices, the contemporary, scientific and knowledge-based psychotherapy has a relatively short history. It is agreed that its emergence happened upon the publication of Sigmund Freud and Josef Breuer's book entitled "Studies on Hysteria" (1895), which started the first school in psychotherapy, i.e. psychoanalysis. Ever since, a huge number of schools and currents of psychotherapy have been created (there is currently ca. 500 of them!), which makes it significantly difficult to define this peculiar profession. Speaking more broadly, however, psychotherapy means each and every method of treating mental or psychosomatic disorders using intentionally specialised psychological measures (Grzesiuk, 2005). In particular, psychotherapy is an experience that may lead to a better understanding of oneself and that, in turn, may improve the psychosocial functioning and the quality of life of psychotherapy clients (Francesetti et al., 2016; Zinker, 1991). Psychotherapy is sometimes confused with many forms of professional psychological activities. Please note that psychological counselling, psychological diagnosis, crisis intervention, psychological skill training, coaching, mentoring etc. are not psychotherapy. What is more, psychotherapy has its non-professional side as a lot of people present themselves as "psychotherapists" even though they do not have any qualifications to do so. Psychotherapy does not involve giving "good advice on how to live" or ready-made solutions to different problems – it involves as little (or as much) as accompanying a client in the process of better understanding of what they are and what they really need or not need. Remember that the clients of psychotherapy are the best experts in themselves. After all, for psychotherapy to be effective, it requires mutual

Kazimierz Dąbrowski (1979), a Polish psychiatrist and psychologist, was the author of the theory of positive disintegration. He meant a process of developmental change, which is immanent to humans – that is it happens to everyone and is a necessary stage in the actualisation of one's true potential. The moment of disintegration is usually not pleasant, often filled with tension and anxiety, tiredness and pain, doubt or breakdown (let us recall the hardships of puberty: mood swings, hurting body, restlessness). Working on yourself can be compared to a renovation of a house – more or less capital, with or without destruction of the walls. To get better, it must first get a bit worse. In psychotherapy, we rebuild non-functional models of behaving and experiencing into more functional ones. We touch emotions that were long frozen, which we pushed deep under our skin with our willpower (often as children). And after several, several dozen meetings with a psychotherapist it turns out that as we deepen our breathing and regain contact with ourselves and another human being, we have some desires which might be unsatisfied (and it might hurt!), or we get sad or furious when we realise that our parents actually did not give us what they should have. The question I often ask myself and my clients is, "what is this whole suffering for?" Why should I torment myself so much? Isn't it better not to feel? No, it isn't. The cause of our current problems might hide in the lack of experiencing of those emotions. On the other hand, when we express them and integrate them with ourselves, we can deal with our current matters with more force and relief. There is also an additional benefit derived from such "working through" unpleasant stories, feelings and aspects of ourselves. Namely,

A lot is being talked nowadays about a peculiar epidemic of depression, particularly in highly developed countries. Such unfavourable features of big city life as overpopulation, excessive noise, haste, ubiquitous consumerism and superficial relationships with others all contribute to the widespread sense of loneliness, emptiness or depersonalisation – states leading to depression very frequently (Pużyński, 2005). Depression is a source of suffering for millions of people around the world. In some, it results in only a transient disappearance of the willingness to live, showing by cyclical states of apathy and discouragement; in others, it wreaks havoc in life, often leading to permanent disability and even to the most tragic effect of that terrible disease – suicide. As Erich Fromm (1970) stated, the "age of anxiety," which reigned during the Cold War, has been followed by the "age of melancholy." Epidemiologic studies carried out worldwide are showing that ca. 17% of the general population suffers from depression during their lifetime. 12-25% of patients reporting to their general practitioner suffer from depression, out of which a half meets the criteria for moderate or severe version of this disease. However, it would be an oversimplification to state that people did not suffer from depression in the past. History shows that regardless of the time and the cultural environment, man experienced this state in a similar way – it was an inability to active participation in social life. In antiquity, clear accounts on the state of melancholy can be found in works of Plutarch, Aretaeus, Gailen and Hippocrates. These accounts do not significantly diverge from what is observed in patients with depression in this day and age. Here, it is worth quoting the abovementioned Plutarch (after Pużyński, 1988): ". . . man in depression exaggerates the smallest evil under the influence of anxiety. They

Ever since the emergence of modern psychotherapy, there has been a dispute around its scientific status (see Cook et al., 2017; Chrząstowski, 2019; Eysenck, 1952; Lambert, 1992; Rakowska, 2005). Are the psychotherapeutic theory and practice based, or should they be based, on scientific data, just like medicine (see evidence-based medicine)? Or is psychotherapy rather a set of practical skills which can be practiced like craft? Perhaps the psychotherapist should only use their unique intuition and clinical experience while working with people and not subject themselves to the rigid criteria of scientific assessment, and psychotherapy is a form of art and each psychotherapist is an artist to an extent? Trying to answer the above questions, we need to attempt to combine two issues that are difficult to combine at first glance. On the one hand, you need to take into account the criterion of scientific viability from the perspective of philosophy of science (Brzeziński, 2019). On the other hand, the theory- and research-based object of psychotherapy needs to be taken into account, as well as its non-homogeneity, interdisciplinarity and peculiar entanglement into many different disciplines of science – from philosophy, through psychiatry, psychology, sociology, culture studies, down to neurobiology even (Kratochvil, 2003). Simply speaking, sciences can be divided into formal (e.g. mathematics and logic) and empirical sciences, which are classified into natural (e.g. physics and biology), humanistic and social (e.g. philosophy and psychology). In such a perspective, psychotherapy can be classified under empirical studies, but some of its modalities are closer to natural sciences (see the cognitive-behavioural modality) or humanistic and social sciences (e.g. the humanistic-existential modality). This peculiar methodological split – that is manoeuvring between the methodology of natural sciences (see behaviourism, neopositivism), the methodology of humanistic and social sciences (see mentalism and phenomenology) and the contemporary integrative and transtheoretical

More or less since the 1950s, empirical studies started to be carried out into a widely understood effectiveness of psychotherapy (Rakowska, 2005). They attempted to answer fundamentally three questions: a. Is psychotherapy an effective method of treatment and/or supporting people struggling with mental disorders, particularly in comparison to pharmacotherapy?b. What factors affect whether psychotherapy is or is not effective?c. What is the effectiveness of individual schools of psychotherapy? The discussion in this respect was started by an eminent personality psychologist, Hans Eysenck (1952), who carried out a meta-analysis of several dozen studies into psychotherapy effectiveness conducted at the time and came to the conclusion that a more or less the same number of psychiatric patients achieve improvement through psychotherapy and heal spontaneously without any psychotherapeutic intervention. However, literally hundreds of alter studies on psychotherapy effectiveness analysed in a lot of meta-analyses challenged the conclusions of Eysenck and provided reliable empirical data proving the fact that psychotherapy is not only an effective form of treatment of mental disorders, but also a method significantly supporting the development of humans and improving the quality of their lives (see e.g. Bergin, 1971; Elkin et al., 1988; Lambert, 1992; Luborsky et al., 1975; Smith and Glass, 1978). What is more, the turn of the 20th and 21st century brought fascinating discoveries from the border of psychotherapy and neurobiology indicating that psychotherapy can have an equally significant effect on the functioning of the brain as pharmacotherapy (see e.g. Etkin et al., 2005; Gabbard, 2000). As a result of the above, the World Health Organisation (WHO) regarded psychotherapy as an equally effective method of helping individuals with mental disorders as pharmacological treatment (WHO, 2001). However, it proved more problematic to receive an answer to the two remaining questions, particularly the one concerning the comparison of the effectiveness

When we see deep and painful discouragement, cessation of interest in the external world, loss of the ability to love, inhibition of every single skill (Freud, 1970), we see a person engulfed in unhappiness. The image of that unhappiness can be similar in depression and mourning, which is shown in Robert Redford's film entitled "Ordinary People" (1980). It tells a story of an American family from the upper middle class, whose members deal with the death of Buck, an older son, in very different ways. The mother (Mary Tyler Moore) becomes indifferent and is emotionally distant from the family, but she keeps the appearances of normality. The father (Donald Sutherland) strives to be bursting with joy, willing to bring a living son back to life and take care of him. The main character is Conrad (Timothy Hutton), a teen brother of the dead, who participated in the accident with him. We are introduced to the family when Conrad comes back home from a psychiatric hospital, where he ended up after a suicidal attempt. Until we get to know about the tragic death of Buck, Conrad's symptoms indicate depression: he has not strength to get up, has no motivation to act, acts in front of his parents that everything is alright, but he gets angry easily, isolates himself from friends, is evidently in constant tension and, as Freud would put it, suffers from depressed mood expressing in the form of accusations and blames directed at himself, going as far as deranged expectation of punishment (ibid.). In the case of Conrad, the expectation of punishment is all the more justified as he suffers from the sense of guilt because he had survived the accident. Both in mourning and depression – a state formerly known as melancholy – we deal with the loss