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There’s often bewilderment when someone with a history of depression commits suicide. Same goes with someone with history of addiction. There is an erroneous judgement that depression – especially clinical depression – can be overcome by life-style changes, and by ‘being happy’ and ‘positive’. Similarly we think addiction – be it alcohol or substance abuse – can be overcome by willpower alone. What we need to understand is that in these cases, the biggest threat to life comes from within. Today’s Write Tribe's blog prompt is about answering a question. So I’ll try to answer the question about the biological basis of depression and addiction.
I’ll try to use very few technical terms...but even so, bear with me as we tour our brain. So, let’s start with the very basic neurotransmitters. These are chemicals that help ‘transfer’ signals from one neuron (brain cell) to the next. So...let’s say you see a slice of raw mango smeared with salt, chilli powder. Your body’s first ‘reaction’ to this visual stimulus is to salivate. So when I say ‘signals’, I mean a series of electro-chemical reactions
The world of neurotransmitters is delicate, precisely balanced and a LOT of vital body functions depend on optimal levels of these chemicals. Even slight variations can affect you in different ways – insomnia, increased/loss of appetite, aggressiveness and so on.
In the case of depression and addiction, two important neurotransmitters play a critical role – Dopamine and Serotonin. Both these are vital in the overall functioning of the human body. For example, serotonin regulates mood and feeling of wellbeing. It also regulates your sleep cycle, and it is the neurotransmitter that signals ‘hey stomach is full, stop eating’. In other words, it regulates the portion of food you can eat (the brain tells you...this is enough on the plate). Yeah...if you are the one who is known to eat 30 dosas and 80 idlis in one sitting...consuming quantities disproportionate to your lifestyle and body weight, stop being proud of your ‘prowess’. There’s probably a malfunction in your serotonin levels. You might find yourself suffering from insomnia, you are needlessly impulsive, restless, aggressive and always fidgety. Dopamine on the other hand, is very critical for cognition, memory, learning, attention and motor functions.
Research has implicated low serotonin levels in depression. The low level could have various causes – hereditary, diet, life style. This is one of the reasons a class of anti-depressants known as ‘SSRI’s (Selective Serotonin Reuptake Inhibitors) have become a standard prescription for depression. They help increase the serotonin level, alleviating the symptoms of depression.
Low serotonin level is also known to increase the probability of alcohol addiction. In fact, it becomes a vicious cycle. Low serotonin makes one reach out to stimulants. Since alcohol directly hits the bloodstream, there’s a rush of serotonin, giving that immediate spike of energy and loss of inhibition. But that ‘high’ cannot be sustained. Once your drinking session is over, the serotonin drops to its original levels – the depression hitting you like a bucket of ice water. So you again need the stimulant – you reach out for more alcohol.
All this is fired by the brain’s reward and reinforcement system. The nucleus accumbens is the ‘pleasure centre’ in our brain –– it forms a reward circuit. For example, when you see something pleasant – it could be your favourite food, or your favourite person – that ‘pleasure’ you feel is because of a surge of dopamine neurotransmitter in the accumbens. The nucleus accumbens is lined with several dopamine and seretogenic receptors. The dopamine molecules latch on to the respective receptors – like a key being inserted to a lock – this is the ‘activated’ state. So what happens when you take a drug such as cocaine? The surge of dopamine is so high that there are not enough receptors for all the dopamine molecules to eventually latch on to. The result is that there is a high content of dopamine floating in the reward circuit – so the substance abuser experiences a sustained ‘high’. With repeated abuse of alcohol and drugs, you are essentially altering the levels of these neurotransmitters. This leads to a ‘deregulation’ of receptors – in other words, the brain rewires itself by decreasing the number of receptors in response to sustained high levels of neurotransmitters. Finally, a stage is reached when the receptors are constantly activated – example, D2 high or dopamine supersensitivity condition. This can lead to psychosis, schizophrenic symptoms, loss of memory, delusions of grandeur, onset of Parkinson’s. For example, some severe abusers of crystal meth believe there are bugs running beneath their skin – so they literally gouge themselves to remove the ‘bugs’. Because the brain is now accustomed to a very high level of stimulation, the individual can no longer find pleasure in everyday environment – there is a marked disinterest, apathy, nothing can make the person ‘happy’ – this condition is known as anhedonia. The victim now reaches out to drugs/alcohol over and over again to regain that ‘pleasure’.
Even in the case of depression in the absence of addiction, the mind becomes an absolutely dark place – like a maze of underground caves with no exit. One does not see the purpose of getting out of bed – everything seems futile. There is a marked lack of energy, like a deflated balloon – every small movement seems to expend an enormous amount of energy – one would rather sit still on the couch, hungry and thirsty, rather than walk up to the kitchen, open the fridge door and find a bottle of water. It’s like watching someone implode. Suicide is unfortunately a common outcome. The sufferers are persistent in their attempts. You have to understand that these are not suicides committed to escape an external situation...but this is more of a release from a prison of the worst kind...a mental prison.
We see all kinds of enemies around us – rapists, murderers, terrorists. But when your own mind turns against you...you’ll probably come face-to-face with the worst enemy there ever was. God forbid.
© Sumana Khan - 2014