In pursuit of pleasure

A simple, reductionist approach, looking at common human emotions, behaviours and learning patterns, offers a good way to study and describe the roles played by motivation and reward in a variety of different mental health disorders.

According to Professor Andreas Heinz, there is huge biological overlap between mental disorders, and this allows conditions to be viewed collectively in terms of the roles of motivation and reward in defining the features of these conditions. He also reminded delegates that human emotion can similarly be viewed in simple terms, in ways that aid study and analyses. Emotions can be grouped broadly into either positive- or negative-affect axes, and within these groupings, subjects can pass from states of high or low arousal, and can rapidly transition between these emotional states.

The joy of surprise

Having set the scene for his audience, Professor Heinz, who works at the Department of Psychiatry and Psychotherapy, Charité University Hospital in Berlin, went on to stress the importance of learning from reward. Such learning is important for cue-conditioning and affects the elements of anticipation and surprise that are important to the pleasures of reward.

Professor Heinz stressed that wanting and desiring reward and pleasure are very different from liking something. Appreciating this distinction is important when looking at certain addictive behaviours. He noted that learning can lead to reduced fulfilment, noting that many analysts find their patients report that “the desire can disappear in the moment of fulfilment and the fulfilment itself is quite boring.” Professor Heinz also gave another example of behaviours around reward, pointing out that an opiate addict will happily withdraw entirely from most forms of interaction in order to enjoy the pleasure component of their reward.

Surprise rewards are associated with dopamine release, although dopamine per se should not be viewed as a “pleasure” neurotransmitter.

Learning and predicting

Professor Heinz said that surprise rewards are associated with dopamine release, although dopamine per se should not be viewed as a “pleasure” neurotransmitter. Rather, it is involved in pathways predicting reward and avoiding loss. He noted that alcohol-dependent people, even during detoxification, can have inadequate reward-anticipation and learning, linked with aberrations in the dopamine system.

Dysfunctional reward-anticipation can be a feature of mental disorders and here again, the dopaminergic system plays a part. Professor Heinz also noted that in people with alcohol dependency, just as in schizophrenia, there is a slower learning rate around reward behaviours. He said changes in learning are complex, going beyond simple yes or no decisions and involving changes in the cognitive monitoring of the self, that can lead to shifts towards habitual and goal-directed behaviours.

Tense anticipation

Professor Heinz also described how behavioural experiments have shown that in conditions such as alcohol dependence, there can be background behavioural Pavlovian triggers and associations that drive a subject towards drinking, linked with image and auditory cues, where serotoninergic pathways may be involved.

The bigger picture

He also pointed out that stress exposure and increases in cortisol levels, as well as genetic factors, are among the many factors that impact on emotions, motivations, learnings and behaviours.

Last but not least, Professor Heinz stressed to delegates the very important role that environment can play in influencing motivation and behaviour and in contributing to risk for mental health conditions associated with addictive behaviours. He said living in deprived urban areas has been shown to increase a person’s risk for poor mental health. He said that even when corrections are made for fiscal poverty, it has been shown that living in conditions of social stress and deprivation, where social networks are poor and there is chronic social exclusion and stigmatization, the prevalence of major mental health disorders increases.