Stockholm Syndrome: A not-quite love story

Fed up with all the love stories you heard in the last days? Here comes a "not-quiet love story" for you:

by EneKiedis via DeviantArt

Love is complicated. While many may spend a sleepless night worrying about finding “the one”, getting together with “the wrong one” can be just as problematic. When taken to the extreme, developing romantic feelings for an inappropriate mate can be confusing, or even dangerous.
Stockholm syndrome is used to define a cluster of symptoms related to inappropriate feelings from a victim towards an aggressor. Within this framework, “positive” actions of the abuser such as withholding abuse are interpreted as signs of love and affection, and the victim begins to develop empathy toward their captor. The name stems from a famous case in the 1970s, a hostage-taking at a Swedish bank in which the victims developed close bonds with their captors and eventually defended them in court [1,2]. Since then, many more cases have been documented, including many linked to forms of domestic and childhood abuse. Though rare, this syndrome has appeared to capture the public imagination [2].

SIMILAR BEHAVIOR MAY BE OBSERVED IN ANIMALS

 


More formally, Stockholm syndrome forms a part of  “Complex post-traumatic stress disorder” [2].Unfortunately, information about its neurobiological correlates is lacking. Evolutionary psychologists have written extensively about Stockholm syndrome, explaining it as an adaptive mechanism to avoid social strife. The story goes like this: a prehistoric woman is kidnapped from her clan, and must survive to protect her children. Making friends, or better yet, a sexual connection with the abductor provides a higher likelihood of survival, and this type of coping strategy is carried on to the next generation. It’s an imperfect story, yet similar types of submissive behavior may be observed in primates or other animals [3,4].

THERE IS STILL SO MUCH TO UNDERSTAND

 


While important for understanding the nature of Stockholm syndrome, these “just so” stories from the animal kingdom are still a long way away from explaining its neurobiological correlates. If nothing else, however, it shows us just how easily (and frighteningly) our feelings may adapt to life-threatening situations. Somewhere between “heart” and “mind”, there is still so much to discover and understand…


[1] Bejerot, “The six-day war in Stockholm”, The New Scientist, 1974
[2] Fitzpatrick, “Stockholm Syndrome”, Time, 2009
[3] Carson and Price, Aust NZ J Psychiatry, 2007
[4] Speckhard et al, Traumatology, 2005

by Constance Holman, PhD Student AG Schmitz
This article originally appeared June 2014 in Vol. 07 - Issue 2 "Neuroscience of Love". 

In Search of Cupid - Erotomania

According to the Merriam-Webster dictionary, a crush is defined as “a strong feeling of romantic love for someone that is usually not expressed and does not last a long time”. But what happens when a crush goes too far? 

My Phantom Lover by Janet Hetherington

Erotomania or De Clerambault’s sydrome is what we have! Although named after the French psychiatrist, G.G. de Clerambault who first delineated its features in 1942, early descriptions of the syndrome date back to Hippocrates [1].

Erotomania is a rare psychological disorder that is marked by the delusional belief of a person (usually a woman) that a man, typically of higher social, political or economic status, is in love with her [2]. Usually, the woman has had little or no contact with the man and the man is in some way unattainable either because he is married, has no personal interest, or is sometimes even dead.
Two forms of the disorder have been identified so far [2]: Primary erotomania is characterized by delusions unaccompanied by hallucinations. The illness is clearly defined, the onset sudden and the course chronic. These patients are classified into a so-called fixed group where delusions remain unchanged over a period of years. Secondary erotomania on the other hand is usually associated with other psychoses – most commonly paranoid schizophrenia. These patients fall into the recurrent group who are less psychiatrically ill, but have intense delusions that are short lived. Patients with the disorder usually have a family history of psychosis, leading psychiatrists to suspect a genetic component.

PHANTOM LOVER SYNDROME

 
Traditionally, the prognosis and response to treatment is poor. The disorder is overlooked because it is often associated with other well-known psychiatric disorders like schizophrenia, bipolar disorder, and major depression. Treatment involves low-dose neuroleptics and antipsychotic medications. This is sometimes coupled with electroconvulsive therapy for temporary relief of the delusions along with psychotherapy and an adjustment of socio-environmental factors. The success of treatment depends on the co-occurrence with other disorders and the type of erotomania. Although some patients have been cured completely of their erotomanic symptoms with the antipsychotic pimozide, the two longest reported unimproved cases have now been followed up for over 37 and 40 years [2]! 


[1] Rather, The Wellcome Historical Medical Library, 1965, pp 169-184
[2] Jordan et al, J Natl Med Assoc, 2006

by Apoorva Rajiv Madipakkam,
This article originally appeared June 2014 volume 7, issue 02, The Neuroscience of Love 

Love is Chemistry

Though my chemistry classes were never that exciting, people keep saying “love is chemistry”. Does this imply love can be separated into understandable steps and then produced according to a protocol as long as we have the right ingredients? Will we soon be able to develop love potions?

love-potion  source: clipartlog.com

Oxytocin and Vasopressin
The most important ingredients in love chemistry are hormones. They are behind all emotions and also regulate our feelings of love and attachment. Oxytocin and vasopressin are the most prominent hormones implicated in pair-bonding and love, not just between partners, but also between friends, or mother and child [1]. Production of oxytocin, nicknamed the "cuddle and trust" hormone, is initiated by caressing and cuddling and is responsible for the pleasant feeling and comfort this gives us [2]. Principally, oxytocin triggers the muscular contractions required for birth and milk release during lactation, thereby also creating unconditional maternal love. Mothers who have had a caesarian section have, especially in the beginning, a weaker instinct for the cry of their child compared to mums who gave birth the natural way, initiated by oxytocin [3] (read more on maternal love in this issue's 'of Mothers, Methylation and Modernity' on pp. 8). Vasopressin plays its principal role in cardiovascular function and maintains blood pressure [4]. It is however also known as the attachment hormone. It is more important in males; while their oxytocin production is lower than in females, they use this hormone for pair-bonding instead [2,5].

Pair-Bonding
Both hormones are produced by the paraventricular and supraoptic nuclei of the hypothalamus and released into circulation by the pituitary gland, where they will then look for their respective receptors [6]. There are three different types of vasopressin receptors and one type of oxytocin receptor discovered thus far. The vasopressin receptor 1a (V1a) as well as the oxytocin receptor are present in many brain regions associated with love, including the dopamine reward system [7]. This means that at least part of the effect of oxytocin and vasopressin is dopamine-dependent. Research in prairie voles, small monogamous mammals that are used as the animal model for attachment and love, shows that the distribution and density of these receptors play an essential role in pair-bonding [8]. There are also some differences in the effect of oxytocin and vasopressin found in prairie voles. Oxytocin has anxiolytic and stress-reducing effects, and induces partner-bonding in females. Vasopressin on the other hand increases fear and stress responses, and induces partner-bonding in males [2]. This is also true in humans, and it has been suggested that it originates in prehistoric parent-child bonding, where mothers cared and fathers protected against danger [5] (see also "Mono or Poly? Which is our Nature?" on pp. 9).

Dopamine
When binding to the dopamine reward system, oxytocin and vasopressin induce dopamine release, making love a rewarding experience [9]. Dopamine production as well as expression of dopamine receptor 1 (D1) or 2 (D2) in the nucleus accumbens determines the exclusiveness of pair-bonding. Stimulation of D1 induces neuroplasticity and reward-related learning and memory, and blocks the formation of pair-bonds in prairie voles. D2 expressing neurons on the other hand project to the ventral pallidum, which integrates information from the D2-positive neurons with information from the vasopressinergic system to activate neuronal networks that aid in the formation of pair bonds [10]. In prairie voles, D1 expression is up-regulated after the first bonding has taken place, preventing promiscuous behavior [11].

First Phase Hormones
Decreases in serotonin levels are also related to love, especially the rather manic and obsessive behavior during the first phase of romantic love [1]. After this first phase in the relationship serotonin levels recover to normal levels again (see also 'The Course of True Love Never Did Run Smooth' on pp. 5). Norepinephrine [12], cortisol and testosterone [2] levels are also especially important in this first phase.
All in all, many different hormones play an important role in love and how we experience our relationships. However, their effects are not just dependent on hormone levels, but also on number and distribution of receptors. This ensures that the chemistry behind love cannot be summarized and generalized into one protocol, but is an individual mixture.
So, unfortunately, chemistry lessons will stay rather static and not so exciting; love potion brewing is not yet ready to be taught in the classroom.


[1] Zeki, FEBS lett, 2007
[2] De Boer, Neuroscience, 2012
[3] Weisman, Arch Wom Ment Health, 2010
[4] Earley, Ann N Y Acad Sci, 1966
[5] Mieras, Liefde, 2010
[6] Debiec, FEBS lett, 2007
[7] Bartels, Neuroimage, 2004
[8] Insel, Proc Natl Acad Sci U S A, 1992
[9] Young, Nat Neurosci, 2004
[10] Edwards, Nat Neurosci, 2006
[11] Aragona, ILAR J, 2003
[12] uberdionysus.livejournal.com

by Judith Houtman  
This article originally appeared June 2014 volume 7, issue 02, The Neuroscience of Love 

Rules of Attraction between the Sexes

What is the reason that men and women differ so significantly in their behavior and their views when it comes to matters of love and relationships? Why is it, if the two sexes are meant for each other, often so difficult to co-exist in the context of a relationship or a marriage?

Albrecht Dürer (1507) - Adam und Eva,
Prado museum, Madrid

The Psychosocial Perspective
According to the biopsychosocial model, the social environment and the psychology of the two sexes, in combination with the biological background, contribute to the behavior they manifest when they are sexually mature. From the perspective of evolutionary psychology the between-sex differences in humans can be traced back to primeval times, when the pressure of a different physical and social environment pushed them to assume different social roles that eventually led to the development of different psychology. As reproductive status was an important parameter during this time, the two sexes adjusted their behavior in order to ensure better survival and reproductive success. Therefore the females developed traits and skills that increased the survival of their offspring while males were less concerned with reproduction [1]. This, however, does not mean that the sexes have stopped evolving since then. On the contrary, the results of the radical social changes that have occurred in the last few centuries can be seen in the psychology of both sexes. In principle, in society, the sexes will assume the roles in which they have a better chance of succeeding, and in turn they will further develop social skills that will ensure their success in the given social position.
In the context of psychological studies, participants were asked about the desirability of certain characteristics in a prospective husband or wife. The results showed that physical appearance and earning potential were valued more by males and females respectively, consistent with the aforementioned theory [2]. Another study investigated in more detail which physical features men and women found attractive in a long- and short-term partner. Interestingly enough, first in preference was “Body, build” for both sexes, but in the second and third position were the “Mouth, smile” and “Height” for women and “Face” and “Eyes” for men. Moreover, both sexes prioritized the physical characteristics of their short-term partners over those of their long-term ones [3].

Male and Female Brain Areas of Love
The role of biological background must not be neglected in any case, as it provides more concrete evidence on the matter. Differences in the “rules of attraction” between males and females have been documented by the different activity rates of certain brain areas during “romantic” love. In particular, a stronger activation of the areas that integrate the visual stimuli was recorded in males, signifying their focus on physical appearance. Females, on the other hand, seem to focus more on social status as witnessed by activation of brain areas associated with attention and emotion. These different patterns of activation could indicate, in accordance with the theory of evolutionary psychology, the priorities that each gender has for the formation of a family, namely, the young and healthy woman that is more likely to bear offspring for the male and the security and resources that a man should provide for the female [4].
During sexual arousal as well there seem to be functional differences between the two sexes, as an fMRI study found greater activation of the hypothalamus in men compared to women when they were shown erotic films. In addition, sex drive, defined as the desire for sexual gratification, seems to be related to circulating levels of testosterone in both sexes, and more specifically to the balance between androgens and estrogens. The disruption of this balance during the menstrual cycle in women results in an increase in the sexual drive. In both sexes, a decline in sexual activity occurs with the decrease in androgens during aging [4].

Gender Differences in Animal Studies
Further evidence supporting the biological differences comes from animal studies. Differences in the hormones promoting attachment in prairie voles have been proposed. In particular, vasopressin and oxytocin were found to be more important for males and females respectively. Additionally, gender differences in the types and distribution of hormone receptors were found in the same species [5]. In another study, social interaction with rats of the opposite sex led to a different response to stress stimuli between male and female rats. Male rats that were housed with female ones showed reduced stress levels compared with male rats that were bred in isolation after exposure to the stress stimuli, while for the females such a difference was not found [6]. The different way male rats experience social interaction with females, as a means of relieving stress, suggests the use of different strategies for managing stress that possibly apply also to the early stages of romantic love.
This combined evidence illustrates the presence of meaningful sex differences that stem from biological, social and psychological variations. Further investigation of these topics could have significant applications for resolving the relationship and sexual problems that many couples face.


[1] Eagly et al, American Psychologist, 1999
[2] Buss, BuJ Cross Cult Psychol, 1990
[3] Li and Kenrick, J Pers Soc Psychol, 2006
[4] Fisher et al, Philos Trans R Soc Lond B Biol Sci, 2006
[5] Lim et al, Neuroscience, 2004
[6] Westenbroek et al, Horm Behav, 2005

By Andreas Antonios Diamantaras, Master's Student Medical Neurosciences

This article originally appeared June 2014 volume 7, issue 02, The Neuroscience of Love  

Through Rose-Colored Glasses

People who fall in love tend to adopt curious and nerve-racking behaviors: they think and talk about nothing else but their lover and seem unable to concentrate on simple daily tasks. It is as if they see the whole world through rose-colored glasses.

Photo: D Sharon Pruitt

For a neuroscientist, this sounds a lot like impaired cognitive control. It has even been suggested that these behaviors resemble those of patients with obsessive–compulsive disorder [1]. How unsurprising then, that groups of neuroscientists set out to examine this more closely! The group of van Steenbergen et al. [2] studied the effect of passionate love on cognition in 43 students (23 girls, 20 boys) who had recently become involved in a romantic relationship. To test how 'in love' the participants were, the Passionate Love Scale was used (yes, such a scale really exists). For assessment of cognitive control, the flanker task and a Stroop task were performed – both tests measure the ability to filter out distracting and irrelevant information and therefore require cognitive control. Before taking the tests, the participants were asked to imagine romantic events with their lovers and listened to love-related music to elicit a “romantic” mood.

Reduced Cognitive Control in Lovers

The authors were able to show that higher scores on the Passionate Love Scale were associated with an increase in the interference effect on the two cognitive tasks. This effect was independent of gender and not influenced by self-reported affect. Thus, the study showed that cognitive control really is impaired on a measurable level in the initial phase of passionate love. In other words: The rose-colored glasses are real!

Reduced cognitive control has been associated with increased impulsivity in some models and can also be observed to a similar extent in addicts [3]. So from a neuroscientific perspective, passionate lovers in the early phase of their relationship seem to resemble high-impulsivity addicts with obsessive-compulsive disorder.

Luckily, for us, this does not last forever. When a passionate relationship evolves into a more committed long-term relationship, cognitive control becomes increasingly important and is eventually reestablished [4].

[1] Tallis et al, Psychologist, 2005

[2] van Steenbergen et al, Motiv Emot, 2013

[3] Burkett & Young, Psychopharmacology, 2012

[4] Pronk et al, J Pers Soc Psychol, 2010

By Ann-Christin Ostwaldt, PhD Student Medical Neurosciences (AG Academic Neuroradiology)

This article originally appeared June 2014 volume 7, issue 02, The Neuroscience of Love  

Love at First Sight

Valentine's Day is only two weeks away. In anticipation of this, the next blog posts will cover topics that center around the neuroscience of Love.


The idea of love at first sight has been around since the times of Plato and has since been promoted by western media [1], but does it really exist?

by raquelcarmo via pixabay

We define romantic love as a state where one experiences strong loyalty, trust, tolerance, physical attraction, and empathy toward someone [2]. However, many of these emotions require a long time to cultivate. This would contradict love at first sight from the get-go, but if “falling in love at first sight” is a continuous process as the “falling” implies, then it could also be defined as a strong readiness or certainty to develop those emotions.

The two-factor theory of emotion proposes that both physiological arousal and cognitive label are the basis for emotion [3]. As such, an increased pulse from climbing stairs might be interpreted as fear or love depending on the emotional cues present in the immediate environment; for example the person or task waiting at the end of the stairs. A study along those lines asked people before and after a rollercoaster ride to rate a photograph of a person from the opposite gender. After the ride, the participants rated the same photograph higher in terms of attractiveness and desirability to date [4].

Upon first encounter, there are a few key features which determine whether we find a person attractive. These include waist-to-hip ratio (of optimally 0.7 for women) and facial symmetry, preferably a face similar to our own [5]. Other factors require some closer observation: middle finger length, lung volumes, and metabolic rate [5]. Human fMRI studies on loving couples have revealed the brain areas activated when pictures of their partners were shown [6]. Areas involved in sight recognition and love were dopaminergic (e.g. the putamen and caudate nucleus), associated with reward, and also areas involved in somatosensory integration. Incidentally, there is a striking overlap with brain regions activated by euphoria-inducing drugs such as cocaine. The amygdala, on the other hand, deactivates the brain areas responsible for the condition of love causing depression and emotional stress or, in this cas,e a broken heart.

So, what about you? Have you seen love at first sight?


[1] http://tinyurl.com/lxk9h2v
[2] http://tinyurl.com/lqekluu
[3] Khan, Physiol Psychol, 1962
[4] Metson and Frohlich, Arch Sex Behav, 2003
[5] http://tinyurl.com/kvmzuva
[6] Ortigue et al, J Sex Med, 1999


By Rick Cornell Hellmann, PhD Student Medical Neurosciences, AG Spinal Cord Injury
This article originally appeared June 2014 volume 7, issue 02, The Neuroscience of Love