People suffering from anxiety and depression have become well versed in the affects of serotonin on the brain. We are all familiar with this neurotransmitter that is affectionately referred to as the happy hormone. Anti-depressant drugs are selective serotonin reuptake inhibitors (SSRI’s). These drugs work by increasing the levels of serotonin in the brain. It does this by by blocking the reabsorption of serotonin, so that more serotonin is available. It’s a clever little trick. In fact it’s the same trick we use by consuming substances of addiction. What we don’t hear a lot about is dopamine.
Research has found that dopamine plays a big role in depressive illnesses.1 Dopamine is another neurotransmitter that the brain emits, in order to keep us feeling good. But moreover its role in the brain is different from serotonin. Dopamine is the motivation hormone. It’s the one that gives you that get up and go feeling. These two neurotransmitters, serotonin and dopamine work side by side in the brain. It’s why depression can tend to fall into two categories, depression based on low serotonin or depression based on low dopamine.
Low Serotonin Depression
Serotonin is your feel good mood neurotransmitter so it’s not surprising that when you’re low in it, fluctuation in your moods is one of the first symptoms of this type of depression. Lack of serotonin results in mood swings, sugar cravings, constant worrying, insomnia and a pervading sense of sadness. It’s more likely to illicit OCD type symptoms, obsessive thoughts and compulsive behaviour. Serotonin depression can also manifest in feeling suicidal or alternatively being very aggressive.
Low Dopamine Depression
This is your thinking neurotransmitter. So people low in it, or suffering from dopamine based depression often suffer from foggy brain. They have difficulty thinking; have a poor memory, and a slow reaction time. They may also feel a lack of lust for life. A ‘what’s the point?’ feeling. They no longer feel pleasure whilst engaging in once was pleasurable activities. The shine has well and truly gone out of life. They have no motivation and find it difficult to get anything done. They sleep a lot.
There is no denying there is some overlap between low levels or both serotonin and dopamine in terms of depression. A person may be equally depleted in both of the neurotransmitters giving rise to having symptoms from both categories.
What we’re going to look at in this article is dopamine and the role it plays in our mental health and how it relates to substances we consume to make us feel good. Most drugs of abuse work by flooding the brain with dopamine. Alcoholics and drug addicts have all been found to be extremely low in dopamine2. Researchers have also found sugar addicts are depleted in dopamine.3 Sugar, cocaine, nicotine, caffeine and alcohol4, all increase the levels of dopamine in the brain by blocking the dopamine transporter stopping the dopamine being reabsorbed by the brain.
This means the brain starts to produce a build up of dopamine in the synapsis giving the user a ‘high’. Some drugs like cocaine actually increase the brains level to secret dopamine, which means it’s working from two angles, stopping the brain reabsorbing the dopamine and whilst increasing it at the same time.
Once the dopamine is expended the brain now deficient in dopamine, results in the subsequent crash. This requires additional substance use to jack up the dopamine levels. Continued use of substances such a cocaine down regulate the number of dopamine receptors. This means there are fewer sites for the dopamine to bind to, giving rise to a low dopamine brain chemistry. It is as they say, a vicious cycle.
But it’s not just drug use that will deplete your dopamine levels.
Stress will deplete dopamine, as will not sleeping properly, or by having adrenal issues, or by consuming an unhealthy diet (a diet high in sugar and saturated fats). A study by the Franklin Institute reported that caffeine; alcohol and sugar cause dopamine deficiency in the brain. Being obese is a dopamine killer too.
In our follow up article we’ll take a look at some of the symptoms you’re likely to experience if you’re low in dopamine. We’ll also review ways to increase your dopamine levels to help break the circle of dependency.
 Reduced Brain Norepinephrine and Dopamine Release in Treatment-Refractory Depressive Illness. Evidence in Support of the Catecholamine Hypothesis of Mood Disorders. Gavin Lambert, PhD; Mats Johansson, MD, PhD; Hans Ågren, MD, PhD; et al Arch Gen Psychiatry. 2000;57(8):787-793. doi:10.1001/archpsyc.57.8.787
 Dopamine in drug abuse and addiction: results from imaging studies and treatment implications N D Volkow1,2,3,5, J S Fowler4, G-J Wang3 and J M Swanson6 Molecular Psychiatry (2004) 9, 557–569. doi:10.1038/sj.mp.4001507 Published online 6 April 2004
 Evidence for sugar addiction: Behavioral and neurochemical effects of intermittent, excessive sugar intake. Nicole M. Avena, Pedro Rada, and Bartley G. Hoebel* Neurosci Biobehav Rev. 2008; 32(1): 20–39.
 Neurotransmitters in alcoholism: A review of neurobiological and genetic studies. Niladri Banerjee Indian J Hum Genet. 2014 Jan-Mar; 20(1): 20–31.
 Increased dopamine tone during meditation-induced change of consciousness. Troels W. Kjaera, Camilla Bertelsena, Paola Piccinib, David Brooksb, Jørgen Alvingc, Hans C. Lou