Psychotherapy

Psychotherapy can be defined as the attempt to reframe consequences of maladaptive behaviour that have caused suffering in self or others by scientifically evaluated psychological interventions. The response to psychotherapy does not solely rely on the specific technique. Instead, it is the quality of the patient–client relationship that determines the outcome of psychotherapeutic interventions. In spite of the relevance of early experiences with caregivers and significant others for well-being later in life, few psychotherapeutic ‘schools’ explicitly refer to evolutionary theory. However, evolutionary thinking in psychotherapy has a lot to offer, beyond issues pertaining to attachment theory. The concept of self-deception can explain phenomena related to repression and how some therapeutic interventions work. The ability to mentalize is deeply rooted in our biology and is actively used in psychotherapy. In summary, integrative approaches to psychotherapy are much more in line with human evolutionary biology and neuroscience than puristic psychoanalysis or behaviourism.

Personality disorders

Personality disorders (PD) concern inflexible and maladaptive cognitive, emotional, and behavioural patterns, which cause significant functional impairment or subjective distress. One group of PD is characterized by ‘eccentricity’, another by ‘dramatic’ behaviour, and a third cluster by predominant anxiety. Personality traits reflect individual patterns of behaviour that serve the purpose to achieve important biosocial goals. These behaviours can be grouped according to their interpersonal meaning: dominance versus submission; competition versus cooperation; dependence versus nurturance; assertion versus avoidance; aggression versus defence; and risk-taking versus harm avoidance. From a life-history perspective, personality traits, as well as personality disorders representing the extremes of variation of normal trait distribution, can be differentiated into ‘fast’ and ‘slow’ life-history strategies. Predictions about future resource availability arise from early childhood experiences with caregivers and the interaction of these experiences with genes involved in the regulation of aggression, attachment, etc.

Anxiety disorders

Anxiety disorders comprise a group of syndromes that revolve around fear or worry elicited by specific situations and objects (i.e. phobias), or occurring independently of specific triggers (general anxiety disorder). They are accompanied by autonomic nervous system activation, including sweating, tachycardia, tremor, and nausea. Avoidance of the precipitating stimulus is typical. Anxiety disorders occur in response to perceived danger or threat. Accordingly, flight or freezing may follow. At the cognitive level, anxiety disorders are associated with increased uncertainty about future threats, and at the emotional level with feelings of uncontrollability and unpredictability. Like depression, anxiety disorders are concerned with harm avoidance and defence. Fear and anxiety are among the most common evolutionarily conserved emotions. Following the analogy of the smoke detector, thresholds for fear responses are low, which may explain why so many false alarms occur. Threshold-lowering factors include impending abandonment or the perception of social threat.

Autism spectrum disorder

Autism spectrum disorder (ASD) is characterized by social communication deficits, impaired social interaction, and restricted and stereotyped behaviours and interests. The typical onset is during early childhood. Behaviourally, people with ASD have difficulties in tolerating proximity. Insecure attachment is frequently observed. At the cognitive level, people with ASD have selective difficulties in mentalizing or ‘theory of mind’, possibly related to a dysfunctional mirror neuron system and alterations of the oxytocin system. Conversely, many with ASD (particularly those formerly diagnosed with Asperger’s syndrome) have superior technical skills. It has been hypothesized that the brains of individuals with ASD are skewed to maleness, possibly linked to genomic imprinting of paternal genes. The preservation of genes that predispose to ASD may have undergone sexual selection fostering ‘slow’ life-history strategies. None of the evolutionary hypotheses on ASD is conclusive so far, but open to empirical testing.

Principles of evolutionary theory, evolutionary psychopathology, and genetics

Darwin’s work on evolution by natural and sexual selection is the central scientific framework in biology that explains how life developed through adaptation to changing environments. Evolution has been the driving force that has shaped the human brain and mind in the same way as it has formed somatic traits. Many adaptations pertaining to human cognition, emotions, and behaviour emerged in ancestral environments of evolutionary adaptedness, from which modern living conditions deviate in one way or another. Such ‘mismatches’ of evolved traits and current environments may cause vulnerability to dysfunctional operation of cognitive, emotional, and behavioural traits. Genes and environment interact in manifold ways, yet genetic plasticity may not only convey vulnerability to dysfunction. Instead, the very same genetic variants that may lead to dysfunction when associated with environmental adversity exert protective effects against dysfunction when environments are more favourable. These insights have yet to be acknowledged by psychiatry and psychosomatic medicine.

Somatic symptom and related disorders

Somatic symptom disorders are characterized by the presentation of somatic complaints (somatization), often, but not necessarily, in the absence of a medical explanation of these sensations. The level of concern is generally disproportionate in relation to the severity of the somatic illness. Behaviourally, somatic symptom disorder entails signals that call for help and attention from others. Evolutionary considerations of why people present with somatic symptoms in the absence of a medical cause suggest that this behaviour could reflect a strategy to manipulate others in order to evoke care. Signals that aim at eliciting care from others are more persuasive if the ‘real’ intention is hidden from conscious awareness. Thus, self-deception may be involved in the presentation of somatic symptoms. Within the spectrum of somatic symptom and related disorders, the degree of self-deception may vary from high, as in illness anxiety disorder, to relatively low, as in factitious disorder.

Obsessive-compulsive and related disorders

Obsessive-compulsive and related disorders comprise several syndromes, to which repetitive thoughts or behaviours are central. Compulsive behaviour is concerned most with hygiene, orderliness, checking, grooming, and hoarding, whereas obsessive thoughts (rumination) focus on harm avoidance and cultural taboos. Compulsive behaviours resemble stereotypic movements seen in animals or cultural rituals. Cognitively, anticipating potential future risk scenarios may help in minimising threat, suggesting that obsessivecompulsive disorder may be a by-product of foresight. Obsessive-compulsive disorder is often linked to life events that require heightened vigilance for threat, including sexual maturation (puberty), pregnancy, and childbirth. While most individuals with obsessive-compulsive disorder follow a ‘slow’ life-history strategy, cases with increased impulsivity and reduced inhibitory control seem to pursue a ‘fast’ life-history strategy.

Bipolar and related disorders

Bipolar disorder concerns a syndrome in which both manic and depressive episodes occur, or states where manic and depressive symptoms cooccur. Mania is characterized by elevated mood, drive, and accelerated cognition. Behaviourally, mania reflects an extreme phenotypic variation of cognitive, emotional, and behavioural traits involved in competitiveness and dominance. Evolutionary explanations of mania suggest that dilute versions of the syndrome may confer increased reproductive success, which could partly account for the preservation of genes that predispose to bipolar disorder. Life-history perspectives suggest that mania reflects a ‘fast’ life-history strategy. Why such a strategy can switch—sometimes rapidly—to the extreme of a ‘slow’ strategy (i.e. depression) remains unclear.

Psychiatric assessment

Clinical assessment of patients and therapeutic interaction relies on the clinician’s interpersonal skills. The psychiatric interview serves the purposes to understand signs and symptoms in terms of their (maladaptive) meaning, to ascertain a (preliminary) diagnosis, and to initiate therapy. The clinician’s task, therefore, is to simultaneously listen to the patient’s subjective report, observe the patient’s non-verbal and paraverbal behaviour, and be attentive to his or her own emotional reactions (self-reflection). Specifically, sometimes the non-verbal expressions of behaviour tell more about a patient’s inner state than his or her verbal report, simply because the former is less under conscious control. The traditional psychiatric terminology distinguished between cognitive, emotional, and behavioural manifestations of psychopathology. An ethology-based description of non-verbal behaviours according to the meaning of the behavioural unit (eye contact, affiliation, assertiveness, flight, ambivalence, relaxation) is suitable to complement the traditional examination.

Causes of psychopathology

The causes of psychiatric and psychosomatic conditions can be categorized into two groups: proximate and ultimate (evolutionary) causes. Proximate causes comprise genetic factors, epigenetic modulation, childhood trauma and other life events, and senescence. Ultimate or evolutionary causes concern mismatch between adaptation and current environment, suboptimal design, and design compromises. Examples of evolutionary causes of dysfunction include cognitive and emotional adaptations to small-scale societies (mismatch), anxiety (suboptimal design), premature birth (design compromise), and other features associated with human life history. Furthermore, many ‘diseases of civilization’ fall under the category of mismatch, as well as immunological diseases that may arise from a lack of exposure to pathogens early in life. Prevention of psychopathology, though desirable, may not always be possible due to the fact that evolution does not select for emotional well-being. However, reducing the impact of early adversity and helping people develop alternative life-history strategies may be an attainable goal.