Mania, dopamine, and bipolar disorder: exploring reward and regulation within addiction vulnerability

Among the features of bipolar disorder, mania is often described in terms of its outward manifestations: elevated mood, increased energy, reduced need for sleep, or possible shifts toward impulsive or expansive behaviour.

And, while these presentations are clinically observable, they represent only a visible expression of a far deeper neurobiological state¹.

Manic episodes within bipolar disorder reflect a broader dysregulation across multiple systems¹. Dopaminergic signalling, circadian rhythm, autonomic balance, and stress physiology can all shift in concert, altering how reward is processed, how decisions are made, and how internal states are regulated over time^1-2. For affected individuals, these changes are embedded within the body’s regulatory architecture^1-2.

This same architecture can also intersect with vulnerability to substance misuse^3-4. Patterns of addiction frequently emerge along overlapping pathways, shaped by changes in reward sensitivity, impulse control, and attempts to modulate internal states⁵. Understanding these connections and the ways in which they interact enables a more nuanced, less reductive and, ultimately, more helpful view, of both bipolar disorder and co-occurring addiction^3-5.

Make a referral to Harbor London today → 

Mania beyond “mood”: a state of altered neurobiological regulation

During mania, individuals may experience^1-3: 

• Increased goal-directed activity
• Accelerated thought processes
• Reduced need for sleep
• Heightened sociability 

At a purely functional level, these shifts can initially appear advantageous; particularly in pressurised, high-performance, or demanding environments.

Beneath this presentation, however, there is typically a marked change in physiological regulation². The autonomic nervous system often shifts toward sustained sympathetic activation, with elevated arousal and reduced capacity for rest². Sleep–wake cycles  can become disrupted, sometimes rapidly, as circadian signals lose their coherence⁶. Cognitive processes may become faster but less filtered, with the potential for reduced inhibitory control over behaviour¹.

These changes tend to be self-reinforcing^1-2. Reduced sleep can further destabilise circadian regulation, heightened arousal may increase reward-seeking behaviour, and accelerated cognition can reduce reflective capacity^2-4,6. Over time, this can move an individual further from baseline stability¹.

Dopamine and reward signalling in bipolar disorder

Dopaminergic elevation in manic states

Dopamine is central in reward processing, motivation, and salience attribution (the process of assigning importance or prominence to specific stimuli)⁷. During manic states, dopaminergic transmission within mesolimbic pathways is often elevated, increasing an individual’s sensitivity to reward and novelty⁷. 

In turn, this shift can heighten motivation and drive, with individuals experiencing a stronger pull toward goal-directed activity, social engagement, or new opportunities⁷. Internal states, concurrently, may feel energised, purposeful, or unusually “clear”.

As dopaminergic signalling increases, the perceived value of potential rewards may become amplified^7-8. At the same time, the capacity to accurately appraise risk can diminish, reflecting reduced modulation from prefrontal regulatory systems⁷.

Decisions made in this state typically favour immediacy over long-term consequence^1,7. Risk-taking behaviour, changes in relational patterns, or shifts in what might be considered “good judgement” can emerge, often with a subjective sense of confidence that is not fully aligned with objective conditions^1-2.

Post-manic depletion and depressive contrast

Following periods of dopaminergic elevation, compensatory downregulation frequently occurs⁸. Baseline dopamine tone may decrease, contributing to reduced motivation, anhedonia, and fatigue during depressive phases⁸.

In this sense, the oscillation between mania and depressive states reflects a neurochemical as well as emotional cycle⁹. The system moves between positions of (relative) excess and depletion, with limited stability at baseline^1-2,9.

Instability across systems: dopamine, sleep, and stress regulation

Bipolar disorder can be understood as an instability across interconnected regulatory systems^1-2. Dopaminergic signalling, circadian rhythm, and stress physiology operate in constant interaction, influencing one another continuously.

Sleep disruption is a good example of this. Reduced need for sleep during mania is often experienced as an inevitable and comparatively benign feature of the state – yet, in itself, it also acts as a potential driver of further dysregulation¹⁰. Circadian misalignment affects melatonin secretion, cortisol timing, and broader endocrine rhythms, which can weaken the body’s capacity to maintain equilibrium¹⁰.

At the level of stress biology, repeated episodes can alter HPA (hypothalamic-pituitary-adrenal) axis function – the body’s primary system for managing stress – shifting baseline arousal and increasing sensitivity to stressors¹¹. Over time, these cumulative changes contribute to allostatic load: the physiological cost of repeated adaptation without sufficient recovery^1-2,11.

Depending on individual presentations, the result is (often) an internal system that can quickly become more reactive, less predictable, and increasingly prone to oscillation^1-2.

Why mania may increase vulnerability to substance use

The same neurobiological features that define mania can also increase susceptibility to substance misuse^3-5.

Heightened dopaminergic activity enhances reward sensitivity, making external substances and stimuli more reinforcing^7-8. Experiences that amplify stimulation, alter mood, or extend wakefulness may carry increased subjective value during manic states^7-8.

At the same time, reduced inhibitory control and altered risk appraisal can lower the threshold for experimentation or escalation¹². For instance, decisions may be made quickly or impulsively, with less consideration of longer-term impact¹².

Sleep disruption may further compound this vulnerability¹³. Substances may be used in an attempt to regulate internal states: alcohol or sedatives to induce rest, or stimulants to sustain energy or focus¹⁴. Over time, these patterns can become integrated and encoded as attempts at self-regulation^13-14.

Increased sociability and heightened exposure to stimulating environments may also raise the likelihood of access and opportunity for substance use^15-16. It’s important to note, however, that these dynamics reflect predictable interactions between neurobiology, behaviour, and context, as opposed to any “weakness” or “failing” of moral fibre17. There are significantly more complex and nuanced, interwoven, clinically observable mechanisms at work¹⁷. As such, any abstract assertions around “character faults” are not medically valid. 

Co-occurring addiction: a shared neurobiological pathway

Both bipolar disorder and substance addiction involve alterations in reward processing, reinforcement learning, and sensitivity to internal and external cues¹⁸.

Repeated substance use introduces further neuroadaptation¹⁸. Dopamine signalling may recalibrate, baseline reward sensitivity can shift, and cue reactivity may increase – these changes can, in turn, destabilise mood regulation, potentially increasing the likelihood of further manic or depressive episodes¹⁸.

A reciprocal pattern can thereby emerge¹⁸. Bipolar-related dysregulation can increase an individual’s vulnerability to substance use, while substance use itself can amplify instability across the same systems⁴. Over time, this interaction can become embedded within behaviour, physiology, and daily rhythm⁴.

Understanding this bidirectional relationship is critical to effective clinical care.

Functional and relational impact

One of the complexities of bipolar disorder is that capacity may appear intact and undiminished for extended periods^1-2. During manic phases, increased energy, confidence, and productivity can be interpreted – not without some clinical merit – as “strengths”¹⁹.

However, this underlying instability can deeply affect decision-making, consistency, and relational judgement; choices made during elevated states may not align with longer-term goals or responsibilities, and variability in mood and cognition can introduce unpredictability into professional or personal contexts^1-2.

For individuals operating within environments where trust, discretion, and sustained judgement are critical, even subtle shifts can carry disproportionate impact²⁰. Reputational exposure or relational strain may emerge gradually, potentially only recognised once patterns have become established and ingrained²¹.

Recovery as restoration of regulatory architecture

Effective treatment of bipolar disorder (particularly when co-occurring with addiction) requires attention to the systems that have become dysregulated²².

Stabilisation of sleep and circadian rhythm is often foundational²². Re-establishing consistent sleep–wake cycles supports broader endocrine and autonomic balance, creating the conditions for further therapeutic work^22-23. Equally, psychiatric care typically plays a central role in modulating mood instability and supporting neurochemical regulation, while psychological interventions help individuals understand patterns, develop behavioural containment, and strengthen self-regulation^22,24.

Where substance misuse is present, targeted addiction treatment is integrated within this framework, addressing both behavioural patterns and underlying physiological drivers²⁵.

The treatment environment itself can be significant. Settings that offer continuity, reduced external stimulation, and consistent clinical oversight allow for more precise monitoring and adjustment²⁶. Individually-curated care models, in particular, support depth of engagement while maintaining discretion and containment²⁶.

Recovery, in this context, reflects a whole-person journey, and the restoration of encoded internal architecture: more stable dopaminergic signalling, coherent circadian rhythm, improved emotional regulation, and consistent behavioural patterns²⁷. As these systems begin to align, individuals are typically better able to sustain decision-making, relationships, and day-to-day functioning over time^26-27.

For those navigating bipolar disorder alongside addiction, this integrated, system-level approach provides a vital foundation for stability – one that is both clinically grounded, and practically enduring.

Make a referral to Harbor London today →

References:

1. https://www.ncbi.nlm.nih.gov/books/NBK493168/ 
2. https://www.psychologytoday.com/gb/basics/mania
3. https://pmc.ncbi.nlm.nih.gov/articles/PMC8623998/
4. https://www.cambridge.org/core/journals/the-british-journal-of-psychiatry/article/bipolar-disorder-and-addictions-the-elephant-in-the-room/125A34D8E4D994D6DF2BD805E73599F7
5. https://www.sciencedirect.com/science/article/abs/pii/S0165178116318534
6. https://www.sciencedirect.com/science/article/abs/pii/S0165178123000872
7. https://pmc.ncbi.nlm.nih.gov/articles/PMC5401767/
8. https://www.sciencedirect.com/science/article/pii/S0149763425000302
9. https://www.nature.com/articles/s41398-022-01786-4
10. https://pmc.ncbi.nlm.nih.gov/articles/PMC12168795/
11. https://www.sciencedirect.com/science/article/pii/S0306453015009622
12. https://pmc.ncbi.nlm.nih.gov/articles/PMC8623998/
13. https://pmc.ncbi.nlm.nih.gov/articles/PMC4660250/ 
14. https://www.sciencedirect.com/science/article/abs/pii/S0149763422003219
15. https://pmc.ncbi.nlm.nih.gov/articles/PMC6240372/
16. https://pmc.ncbi.nlm.nih.gov/articles/PMC3926100/
17. https://pmc.ncbi.nlm.nih.gov/articles/PMC5486507/
18. https://pmc.ncbi.nlm.nih.gov/articles/PMC2094705/#:~:text=Prior%20epidemiological%20research%20has%20consistently,by%20cocaine%20and%20then%20opioids.
19. https://pmc.ncbi.nlm.nih.gov/articles/PMC5318923/
20. https://pmc.ncbi.nlm.nih.gov/articles/PMC8400362/
21. https://pmc.ncbi.nlm.nih.gov/articles/PMC9448890/
22. https://pmc.ncbi.nlm.nih.gov/articles/PMC3876031/
23. https://www.mind.org.uk/information-support/types-of-mental-health-problems/bipolar-disorder/treatment-for-bipolar/
24. https://www.nice.org.uk/guidance/cg185
25. https://americanaddictioncenters.org/co-occurring-disorders/bipolar
26. https://harborlondon.com/looking-beyond-retreats-and-why-continuity-of-life-matters-for-enduring-recovery/
27. https://harborlondon.com/what-does-sustainable-recovery-look-like-insights-from-clinical-experts/