3.5.9 Motivation, reward and pleasure

Motivation, Reward and Pleasure, Including the Relevance to Mood Disorders, Psychosis and Emotional Instability

Motivation, reward, and pleasure are complex psychological phenomena that are mediated by multiple neural circuits in the brain. These circuits involve various brain regions and neurotransmitter systems, and they play a key role in regulating behaviours related to motivation, reward, and pleasure (Panksepp, 1998).

One key brain region involved in motivation, reward, and pleasure is the nucleus accumbens, which is a part of the brain’s reward system. The nucleus accumbens is activated by pleasurable stimuli and is involved in the experience of pleasure and reward. It receives inputs from various brain regions, including the prefrontal cortex and the amygdala, and it is involved in the release of neurotransmitters such as dopamine and serotonin, which are involved in the experience of pleasure and reward.

Other brain regions involved in motivation, reward, and pleasure include the amygdala, which is involved in the processing of emotions, including pleasure; the hippocampus, which is involved in memory and learning; and the prefrontal cortex, which is involved in decision-making and executive function.

Overall, the neural circuits of motivation, reward, and pleasure are complex and involve the interplay of multiple brain regions and neurotransmitter systems. These circuits play a crucial role in regulating behaviours related to motivation, reward, and pleasure, and they are important for understanding the psychological and neural basis of these phenomena (Berridge, 2007).

Motivation, reward and pleasure in mood disorders:

Mood disorders, such as depression and bipolar disorder, are characterized by disruptions in mood and motivation. Dysfunctions in the neural circuits involved in motivation, reward, and pleasure may contribute to the development and maintenance of mood disorders.

For example, in depression, there is often a deficiency in the neurotransmitter serotonin, which is involved in the experience of pleasure and reward. This deficiency may contribute to the decreased pleasure and motivation that is often observed in people with depression. Similarly, in bipolar disorder, there are often disruptions in the brain’s reward system, which may contribute to the extreme mood swings and impaired motivation that are characteristic of this disorder.

Treatment approaches for mood disorders often aim to restore normal function to these neural circuits. For example, antidepressants, which are commonly used to treat depression, work by increasing the availability of neurotransmitters such as serotonin and norepinephrine, which may help to improve mood and motivation. Similarly, treatments for bipolar disorder, such as mood stabilizers, may work by regulating the activity of brain regions and neurotransmitter systems involved in mood and motivation.

Understanding the neural circuits of motivation, reward, and pleasure is relevant to the understanding and treatment of mood disorders, as dysfunctions in these circuits may contribute to the development and maintenance of these disorders.

Motivation, reward and pleasure in psychosis:

Motivation, reward, and pleasure are often disrupted in psychosis, which is a term used to describe a group of mental disorders characterized by abnormal thoughts, perceptions, and behaviours. Psychosis can be a symptom of various mental disorders, including schizophrenia, schizoaffective disorder, and bipolar disorder with psychotic features.

People with psychosis often experience disruptions in their ability to experience pleasure and reward, and they may have difficulty initiating and maintaining motivated behaviours. These disruptions may be related to dysfunctions in the neural circuits involved in motivation, reward, and pleasure, such as the nucleus accumbens and the prefrontal cortex.

For example, people with schizophrenia, a mental disorder characterized by psychosis, often have deficits in the neurotransmitter dopamine, which is involved in the experience of pleasure and reward. This deficiency may contribute to the decreased motivation and pleasure that are often observed in people with schizophrenia.

Treatment approaches for psychosis often aim to restore normal function to the neural circuits involved in motivation, reward, and pleasure. For example, antipsychotic medications, which are commonly used to treat psychosis, may work by regulating the activity of brain regions and neurotransmitter systems involved in motivation and reward (Koob, 2010).

Motivation, reward and pleasure in emotional instability:

Emotional instability, also known as emotional lability or labile affect, refers to a tendency to experience rapid and frequent changes in mood and emotional states. This can include symptoms such as difficulty regulating emotions, easily becoming upset or agitated, and rapid shifts in mood (Gross, 1998).

Emotional instability is often associated with certain mental disorders, such as bipolar disorder and borderline personality disorder. It is thought to be mediated by dysfunctions in the neural circuits involved in emotion regulation and mood.

One key brain region involved in emotion regulation is the amygdala, which is involved in the processing of emotions, including fear and anxiety. Dysfunctions in the amygdala and its connections to other brain regions, such as the prefrontal cortex, may contribute to emotional instability.

Other brain regions that may be involved in emotional instability include the hippocampus, which is involved in memory and learning, and the ventral striatum, which is part of the brain’s reward system and is involved in the experience of pleasure and motivation.

Emotional instability may also interfere with the normal functioning of the neural circuits involved in motivation, reward, and pleasure. For example, if the amygdala, which is involved in the processing of emotions, is overactive, it may interfere with the normal functioning of the prefrontal cortex, which is involved in decision-making and executive function. This may lead to difficulty initiating and maintaining motivated behaviours and a decreased ability to experience pleasure and reward (Golkar, 2019).

References:

(1) Berridge, K. C. (2007). The debate over dopamine’s role in reward: The case for incentive salience. Psychopharmacology (Berl), 191(3), 391-431.

(2) Golkar, A., Lindström, M., Flyckt, L., Stawicki, S., Kuja-Halkola, R., & Sundquist, J. (2019). Emotional instability and risk of mental disorders: A register-based cohort study. Psychological Medicine, 49(5), 829-839.

(3) Gross, J. J. (1998). The emerging field of emotion regulation: An integrative review. Review of General Psychology, 2(3), 271-299.

(4) Koob, G. F., & Volkow, N. D. (2010). Neurocircuitry of addiction. Neuropsychopharmacology, 35(1), 217-238.

(5) Panksepp, J. (1998). Affective neuroscience: The foundations of human and animal emotions. Oxford University Press.