“Not all addictions are rooted in abuse or trauma, but I do believe they can all be traced to painful experience. A hurt is at the centre of all addictive behaviours. It is present in the gambler, the Internet addict, the compulsive shopper and the workaholic. The wound may not be as deep and the ache not as excruciating, and it may even be entirely hidden—but it’s there. As we’ll see, the effects of early stress or adverse experiences directly shape both the psychology and the neurobiology of addiction in the brain.” 


What is addiction?  


Substance abuse (chemical addictions)  

Activity abuse (behaviour addictions)   


Addiction is often restricted to the ingestion of chemical substances alone. However, excessive and repetitive behaviours (activities) are also classified as addiction. And thus, addiction is defined as the dependence on any substance or any activity.  


Behaviour addictions include:   



Video game playing  

Eating disorders  

Sports and physical exercise  

Media use  

Sex addiction  

Compulsive shopping   


Compulsive criminal behaviour.   


Although behavioural addictions do not involve a chemical intoxicant or substance. Some root causes of behavioural addiction are similar to those of chemical or substance addiction. Behavioural addictions can be passive (Netflix) or active (running).  


What causes addiction?  


A collection of underlying disorders predisposes us to behavioural and substance addiction. All of these disorders reflect low levels of dopamine and/or serotonin. Addiction is a way of ‘self-medicating’. This is because addictive processes increase dopamine and/or serotonin in the brain.  




Obsessive thoughts   

Affective (mood) disorders  

Disturbances in social relationships  

School problems (educational failure and lack of interest in doing homework)   

Occupational or interpersonal difficulties  

Isolation and negligence of friends, family and personal responsibilities  

Mental or physical restlessness   




When an individual reduces or stops a specific obsessive behaviour (their addiction) the following may ensue:  

Excessive fatigue   


Significantly reduced physical activity  

Deprivation and changes in sleep patterns  


Sexual deviations  


Eating disorder   

Withdrawal symptoms   


The six criteria of addiction:  


Salience: Domination of a person's life by the activity.  

Euphoria: A ‘buzz’ or a ‘high’ is derived from the activity.  

Tolerance: The activity has to be undertaken to a progressively greater extent to achieve the same ‘buzz’.  

Withdrawal Symptoms: Cessation of the activity leads to the occurrence of unpleasant emotions or physical effects.  

Conflict: The activity leads to conflict with others or self-conflict.  

Relapse and Reinstatement: Resumption of the activity with the same vigour after attempts to abstain, negative life consequences, and negligence of job, educational or career opportunities.  



Substance and activity addiction:   


The complex interplay of nature (genetics) and nurture (environment) is at the root of both substance and activity addiction. Five contributing aetiologies in the development and maintenance of addiction include: 






SNPs (single nucleotide polymorphisms)   




Dopamine reward system dysregulation   

Emotional dysregulation in the amygdala  

Stress-related shrinkage of the hippocampus and thus impaired learning and memory  




Delta-FosB is a member of the Fos family of transcription factors, which is involved in genetic expression and gene control.  

After multiple administrations of illicit drugs, Delta-FosB, accumulates within specific brain cells (neurons). The two brain regions affected include the nucleus accumbens and dorsal striatum.  


The abuse of drugs and thus accumulation of Delta-FosB, can produce changes in the brain that contribute to the addiction phenotype.  


Studies also found similar accumulation of Delta-FosB in the brain after compulsive running. Thus, Delta-FosB may accrue in many types of compulsive behaviours.  




Addictive behaviours have a strong association with early childhood adversity, neglect and abuse.  

The severity of childhood maltreatment led to abnormal changes in the brain.   


Changes include a reduction in all areas of the left hippocampus, para-hippocampus and anterior fusiform gyrus. The greater the shrinkage in these regions, the more rapid the relapse rate was in substance abuse following treatment. 


A study of 34,600 men and women in the USA, confirmed that all forms of abuse in childhood led to an increase in substance misuse and addiction. The type and intensity of the developed addictions are dependent on the type of childhood abuse and severity.   




Stress exposures – especially in early life with child maltreatment and regular adversity – enhances substance and activity abuse later on in life.   


Stress is also the precipitating factor to many relapses in former or current individuals with addiction.   

People with addiction have notable changes within three areas of their stress response.   


CRF (corticotropin-releasing factor)   

HPA (hypothalamic-pituitary-adrenal axis)   

Autonomic arousal (fight and flight)


Stress = “perception, appraisal, and response to harmful, threatening or challenging events or stimuli.”  


Once acute stress has been overcome feelings of mastery and accomplishment ensue. However, any “stress” that becomes prolonged (chronic) has the potential to become unpredictable and uncontrollable. Resulting in the loss of sensations of mastery or adaptability. And thus, the development of homeostatic dysregulation (loss of our internal balance). This homeostatic dysregulation creates vulnerability and thus, repetitive substance or activity behaviours and tendencies ensue. Eventually leading to possible addiction, in an attempt to stabilise our internal environment.   


SNPs in stress-related genes:  


There is an association between single nucleotide polymorphisms (SNPs) in stress-related genes and addiction.    

SNPs may interact with stress hormones, transcription factors, and cytokines. This interaction may be a potential pathway to identify reliable biomarkers of vulnerability to drug abuse and relapse.  


Therapeutic Target for Drug Addiction:  


CRF receptors in the lateral septum (LS) and the ventral tegmental area (VTA), specifically the CRF2-alpha-R isoform, is a potential therapeutic target for drug addiction.   


The Wnt family of secreted glycolipoproteins - Wnt/beta-catenin pathway may be a critical neural substrate for the interaction between stress and addictive behaviour.  


Researchers also studied the cannabinoid system as a promising target for stress-induced relapse on drugs.


Risk factors:  


Addiction (substance and activity) consistently finds its roots in stressful contexts, particularly when prolonged throughout early childhood.  


Environmental risk factors such as impulsivity, inadequate parental supervision, crime and delinquency also are common across chemical and behavioural expressions of addiction.   


Studies suggest that individuals who engage in one problem behaviour are likely to engage in another problem.   

Sociodemographic risk factors related to poverty, geography, family, and peer groups can also influence the onset and course of both substance addiction and non-substance addiction. 


“The greatest damage done by neglect, trauma or emotional loss is not the immediate pain they inflict but the long-term distortions they induce in the way a developing child will continue to interpret the world and her situation in it. All too often these ill-conditioned implicit beliefs become self-fulfilling prophecies in our lives. We create meanings from our unconscious interpretation of early events, and then we forge our present experiences from the meaning we’ve created. Unwittingly, we write the story of our future from narratives based on the past...Mindful awareness can bring into consciousness those hidden, past-based perspectives so that they no longer frame our worldview. ’Choice begins the moment you disidentify from the mind and its conditioned patterns, the moment you become present…Until you reach that point, you are unconscious.’ …In present