Time for a New Deal Between Neurology and Psychoanalysis

Diego Centonze; Mario Stampanoni Bassi


Brain. 2021;144(8):2228-2230. 

Neurology, and medicine in general, is torn by opposing tensions: universality, which is the goal of guidelines and protocols derived from clinical trials, and singularity, which personalized medicine seeks to understand. Efforts to demonstrate biological bases of diseases and embrace evidence-based medicine have unwittingly contributed to the rejection of what is difficult to generalize: the complexity of individuals, an area where psychoanalysis has the potential to make a major contribution.

Evidence-based medicine relies on randomized clinical trials, where patients are treated as members of a well-defined population with homogeneous qualities. Precision medicine, on the other hand, aims to develop personalized approaches, emphasizing individual differences. Neurology, like many other areas of medicine, is progressing in these opposing directions: generalization—the identification of what different patients have in common—and respect of individuality, crucial to understanding what distinguishes patients within a diagnostic category.

Individual life experiences have an important impact on neurological manifestations in functional neurological disorders (FNDs).[1,2] Freud first proposed, in his explanation of hysteria, that traces of past (real or imaginary) painful experiences can determine physical symptoms and, more intriguingly, that once physical symptoms appear, psychological suffering may actually disappear. In fact, he theorized that hysterical symptoms might be the patient's rejection of the universal knowledge of medicine. Patients say 'what you know in general is not valid for me' or 'with my symptom, that you cannot explain, I embody the exception to your theory'. That is: 'I resist your reductionism in the name of my individuality and complexity'.

Freudian models of symptom formation have been highly influential over the past century among psychiatrists, but have been widely criticized since the 1980s in an attempt to replace them with purely biological explanations, where the relevance of contingent life experiences is diminished. The terminology and diagnostic criteria of FNDs have in parallel evolved over time, yet patients with unexplained neurological symptoms remain in a grey zone between neurology and psychiatry.

The changes introduced by the Diagnostic and Statistical Manual of Mental Disorders-5 (DSM-5) represented a turning point, as they clearly brought FNDs back into the hands of neurologists. According to the DSM-5, the diagnosis of FND requires only the presence of symptoms of altered voluntary or sensory function, together with documented incompatibility between the symptoms and other neurological or medical conditions.[1] An important issue introduced by DSM-5 is that co-existing mental complaints are now not included in the core diagnostic criteria of FNDs, somehow recognizing that Freud was correct in stating the physical symptoms may take the place of—and mask—psychological suffering in these patients.

The multifactorial aetiology of FNDs is captured by a biopsychosocial model where biological, psychological, and social factors all play a role, and in which predisposing conditions (genetics, early childhood events, personality) and precipitating factors (stress, psychological and physical trauma) interact to determine risk. Studies using functional MRI have helped shed light on the pathophysiological bases of some of these disorders. An interesting finding is the abnormal functional hyperconnectivity between limbic and motor networks in patients with FNDs who exhibit abnormal movements. In these individuals, hyperactivity of the limbic system is associated with these movements, which appear involuntary and impossible to control.

To explain the involuntary nature of these disorders, an altered sense of agency (i.e. the feeling of being the author of a given behaviour), associated with impaired function in areas involved in the planning and execution of voluntary movements (supplementary motor area and temporo-parietal junction), has been described.[2] These results are still preliminary, but they provide a physiological basis for the involuntariness of symptoms, which represents one of the most characteristic aspects of FNDs. Moreover, they indicate a role of emotions and, more precisely, altered connectivity between the limbic and motor systems in the development of symptoms. This model resonates with that proposed by Freud, who described somatic symptoms in hysteria as the result of a two-step process, where mental states charged with emotional tones are firstly associated with somatic states, and then repressed from consciousness.[3]

While the number and complexity of pathophysiological models of FNDs are growing rapidly, how to treat them still remains an open question. In the last decades, cognitive behavioural therapy (CBT) has attracted great interest in a clinical context, in part due to its apparently closer proximity to neuroscience. At the same time, however, it might have led to the parallel demolition of the theoretical and practical credibility of psychoanalysis. Indeed, CBT has been developed in a scientific environment, and has paid particular attention to crucial issues such as quantification of effects, and standardization of treatment protocols. The success of CBT is undoubtedly based on certain strengths, such as the availability of reproducible treatments and time-limited interventions. Further, the purpose of CBT is also clearer than that of psychoanalysis. Getting rid of the symptoms is the goal of CBT, something much more practical than the idea of understanding their meaning. However, each of these aspects, while representing the strength of this approach, leaves a number of issues open. According to many critics, the focus of CBT on scientific evidence, which requires simplification and crucially also generalization, overlooks human complexity and uniqueness.

Certainly, psychoanalysis has had little relationship to scientific evidence and research for many years. However, what is interesting about psychoanalysis is precisely that it places the individual at the centre of assessment and treatment. Moreover, a crucial assumption of psychoanalysis, which strongly clashes with the CBT approach, is that most mental activity is inaccessible and, to use a popular expression of Freud, 'beyond the pleasure principle': we literally do not know our motivations and drives. These often guide us towards 'anti-homeostatic' or irrational outcomes, ones that are not easily explained in terms of biological adaptations to the environment. Furthermore, contemporary psychoanalysis has also revised the idea that sexuality is the main drive of behaviour. It recognizes that human desire is opposed to animal needs and instincts, and consists of the key desire to be accepted and recognized by other human beings. According to this conceptualization, the most intimate desire of humans is to be recognized simultaneously as a unique, distinct individual and a perfect member of society/community.[4]

Modern psychoanalysis has also been marked by renewed interest in the field shown by neuroscientists, mainly due to two factors. On the one hand, it derives from the work of psychoanalysts such as Jacques Lacan (Figure 1), who effectively engaged in a dialogue with neuroscience while simultaneously avoiding erasing from their theory and practice concepts and ideas incompatible with biological science.[3] Paradoxically, preserving the specificity of psychoanalysis and at the same time resisting its entire transcription into scientific terms increased its attractiveness to some neurologists and psychiatrists who acknowledge that purely biological and scientific explanations are inadequate to fully account for their everyday clinical practice and interactions with individuals.

Figure 1.

Jacques Lacan. (Blatterhin, 'CC BY-SA 3.0' to: https://creativecommons.org/licenses/by-sa/3.0, via Wikimedia Commons).

The second fundamental contribution comes directly from neuroscience, which in recent years has confirmed that some of the basic assumptions of psychoanalysis are compatible with scientific discoveries. More than 20 years ago, Eric Kandel broke the first boundary between neuroscience and psychoanalysis, showing how Freud's theory anticipated later discoveries in the field of memory trace formation, maintenance and reassociation.[5] In particular, the discovery of long-term potentiation (LTP), as formulated by Hebb but anticipated almost a half century earlier by Freud,[6] allowed translation into neurobiological terms ideas advanced by Freud. His conceptualization was that the neural substrates of some psychological manifestations rely on the formation of strong associations between apparently distant mental, emotional and somatic representations.[7] Hyperconnectivity between limbic and motor brain areas reported in FNDs might be considered one such observable example of pathological strengthening of neuronal communication formed by LTP.

According to Freud's theory, real or imagined traumatic experiences permanently alter brain function, giving rise to abnormal association processes. Dysfunctional unconscious associations between external and internal stimuli, which generate anomalies in the cerebral representation of the external and internal world, can be the basis of mental symptoms. According to this view, symptoms reflect the persistence of aberrant unconscious memory processes, and therefore result from the inability of an individual to erase the long-term effects of a remote adverse event. The formation and consolidation of implicit dysfunctional memories can be considered fundamental to many neuropsychiatric disorders (including obsessive compulsive disorder, anxiety, post-traumatic stress disorder, drug addiction, eating disorders and gambling) with LTP potentially being the key synaptic mechanism governing association formation and connectivity shaping the individual clinical manifestations in these various disorders.[7]

It follows that psychotherapy should aim, if possible, to erase pathological associations—and synaptic changes—underlying dysfunctional implicit memory maintenance.[8] Intriguingly, the paradigms used in CBT, which often involve learning strategies and novel associations, may be largely dependent on memory extinction processes. Undoubtedly, this approach is suitable for widespread application to all patients and a variety of symptoms, requires little or no 'personalization,' and is likely to provide significant results in the short term. Conversely, it is the elaboration around personal life circumstances that generated the first pathological trace to invade the psychic life of the patient that is the main objective of psychoanalysis. The psychoanalytic approach is highly individualized (Figure 2). Generalization is limited to recognizing that the neurophysiological mechanisms involved in the formation of normal and pathological memories are shared by different individuals, yet little can be inferred about personal characteristics, including vulnerability, from the scientific investigation of these mechanisms. What makes a life experience pathological is its meaning for that specific individual. It cannot be understood by studying the features of the external stimulus or the biology of the brain.

Figure 2.

Freud's psychoanalytic couch. © Freud Museum London.

Studies of brain plasticity have helped to give substance to concepts such as the 'meaning' of a symptom, which have long been difficult for neuroscientists to assimilate. However, this requires an acceptance that biological determinism and individual complexity deserve equal attention to better understand the uniqueness of human experience. While advances in genetics and psychopharmacology have demonstrated that mental disorders have a biological background, they have also contributed to a general hostility towards anything that cannot be generalized, and thus to individual complexity. Attention to personalized medicine resurrects the individual after years of trying to dissolve them into biological determinism.

The interest of neuroscience in FNDs has paralleled that in psychoanalysis, and the time has arrived, in our opinion, for neurologists and psychiatrists to examine psychoanalysis more closely, in order to face complex therapeutic challenges in everyday clinical practice, some of which are very poorly managed in terms of outcomes for patients. FNDs perturb many biological, mechanistic concepts that underlie medical practice. They raise the question of whether there is a level of causality that universal rules of biology cannot grasp. But, in so doing, they also present an ideal model to test a new dialogue between two disciplines, neurology and psychoanalysis, that have long remained separate. Being recognized and treated as a unique human being is a major desire of all humans, and conversely, as Freud theorized, hysterical symptoms might be the manifestation of a patient's rejection of general medical knowledge.

With medicine moving at pace towards universal diagnostic and treatment algorithms and a plethora of protocols, we anticipate that FNDs are destined to increase, partly as a manifestation of the resistance of the individual to medical generalization. In this context, a new alliance—a 'new deal'—between medicine and psychoanalysis is of paramount importance if we are to face clinical problems frequently encountered in medical settings, including resistance to treatment. The same principle applies also to mass non-adherence of medical advice,[9] a phenomenon which has been growing in recent years and includes public adoption of measures for COVID-19 and adherence to vaccination campaigns, as has now become all too apparent.[10]