What is Depression?

According to statistics published by the World Health Organization (WMO), depression is one of the most common mental disorders. In 2015 WMO estimated that more than 300 million people (the equivalent to 4.4% of the world’s population) were affected by this condition. It was also the most common cause of disability and suicide deaths in the world (approximately 800.000). 1

Possibly because of its high prevalence, talking about depression has become quite common in everyday life. We will often hear people refer to themselves as depressed when they feel sad, or others who will ensure that a friend or relative is depressed by some situation. And although that could be true in a lot of cases, in order to diagnose depression accurately it is necessary to know exactly what it is, its symptoms, and diagnostic criteria.

What causes depression?

Depression does not have a single cause; on the contrary, it seems to be a result of the complex interaction of a number of biological, psychological and / or social conditions that act as risk factors for the development of this and other disorders.

Over the years, many scientific investigations have been conducted to identify potential risk factors or triggers for depression, and some of the variables that have been found related to it are: to have lived or to be living difficult and stressful situations (such as the death of a loved one, for example) , 5, 6; genetics 5; poverty 8, 9; lack of social contact 7; medical illness and injuries 7, unemployment 10,11; or substance abuse 12; among others .

There has also been found a higher prevalence of depression in women (5.1%) compared to men (3.6%); and a greater frequency of the disorder in older adulthood (above 7.5% among women between the ages of 55 and 74 years, and below the 5.5% in men of these ages), compared to childhood or adolescence. 1

The established hypotheses about the possible causes of depression can then be categorized into three groups: (a) biological / genetic hypotheses; (B) psychological hypotheses; and (C) social hypotheses. As mentioned above, these do not necessarily act independently, and the more risk factors are present in the life of a subject, the greater the likelihood of developing this disorder.

What are the symptoms of depression?

WMO defines depressive disorder as a condition characterized by sadness, loss of interest, inability to feel pleasure, and feelings of guilt or personal worthiness accompanied by disorders in appetite and sleep, the recurrent feeling of fatigue and poor ability to concentrate. Depression significantly affects academic and / or work performance as well as the ability to cope with everyday life. When depression is severe, it can lead to suicide. These symptoms have been present during a certain period of time. 1

In the fifth and last edition of the Diagnostic and Statistical Manual of Mental Disorders, commonly known as DSM-V (a manual used by most mental health professionals worldwide), the definition and diagnostic criteria established for depression are quite similar to those established by the WMO. However, the manual establishes a much broader classification of depressive disorders, depending on factors such as duration, intensity, frequency (in the case of one or more episodes), additional symptoms (such as hallucinations, for example), or its potential triggers (substance use or any medical condition), among others. 2

On the other hand, Aaron Beck (1967), a pioneering psychologist in the study, description and treatment of the disorder, defined depression by referring to five main attributes: (a) an altered mood, which is characterized by the sensation of sadness, loneliness, and / or apathy; (B) a negative self-concept associated with guilt and self-reproach; (C) regressive and self-punitive desires, such as a desire to escape, to hide or to die; (D) vegetative changes such as anorexia, insomnia or loss of libido; (E) alterations in the level of activity (retardation or agitation). 3

Thus, we can note that there is a more or less unanimous agreement regarding what depression is and its main symptoms or characteristics. However, this common agreement does not apply to the causes of the disorder, an aspect in which there are several hypotheses with more or less empirical support, but none of them points to a univocal cause. We’ll talk a bit about it next.


How is depression normally treated?

As for the treatment of depression, many strategies and approaches have proven to be effective, ranging from pharmacological treatment to psychotherapy and participation in support groups. It may happen that a person receives some of these modalities simultaneously, while in others will be possible to do without one or the other option.

For example, the use of antidepressants is not recommended when depression is slight, while in other cases prescription of the drug is a necessary but not sufficient condition for patient improvement. In any case, making these decisions will always be based on the personal history of each patient, the characteristics of the case (Severity, intensity, comorbidity with other disorders, among others), and the recommendations of the relevant specialist (usually a psychiatrist or a psychologist)

As far as psychotherapy is concerned, the approaches or strategies that have proven effective in the treatment of depression are cognitive behavioral therapy, behavioral activation, and problem-solving approaches. It is also common to teach certain relaxation techniques, recommend the patient to perform some type of physical activity or exercise, and promote the integration and participation in certain social groups that can act as support networks (family, community, and/ or friends, are some of the most common networks with which is usually counted).

How does addiction affect Addiction Treatment?

In psychology, it is really difficult to establish causal relationships between variables or conditions, especially at an unidirectional level, which is why it’s most common to hear about influences or relationships between variables, which have been empirically contrasted.

The same happens in cases in which different diseases or psychological conditions occur simultaneously in the same patient (phenomenon designated under the name of comorbidity), specialists do not necessarily establish a causal relationship, and they can also speak of influences or correlations between the different conditions.  In this case, depression presents a high comorbidity with other disorders and conditions such as anxiety disorders, anorexia, and / or substance use, among others.

With regard to the high comorbidity between depression and addictions, one of the investigations in which it has been established a causal relationship between these two conditions is that performed by Swendsen and Merikangas (2000) 12, in the article the authors expressed that according to its results, it is only possible to establish a causal relationship between alcoholism and depression, but for the consumption and addiction to other substances the evidence is less consistent, being more likely that in this population are acting different mechanisms of comorbidity simultaneously.

But, how exactly is the relationship between these two conditions? A study conducted by Grant (1995) found that comorbidity between major depression and substance use disorders affect a large part of the population. In addition, the association is greater between substance dependence and depression than between substance abuse and depression (*).Gender differences were also found for both substance abuse and substance dependence, and the type of drug consumed (e.g., women showed a greater relationship between depression and prescription drug abuse as sedatives and antidepressants In comparison to the group of men). 13

In summary, the relationship between depression and addiction is complicated, not necessarily causal, and varies according to a series of variables such as the type of drug consumed or the sex of the consumer, among others. As one might imagine, the treatment of the conditions presented simultaneously differs in many ways from that which is performed when only one of these disorders is present.

(*) We talk of “dependency” when there is drug addiction and “abuse” when substance use is excessive. Although sometimes both conditions are presented together, they are not interchangeable terms.


Special considerations for people with depression in addiction treatment

As mentioned above, adequate treatment for depression will vary depending on many variables, including patient history and comorbidity with other disorders, including those related to drug use and dependence. In this sense, scheduling a treatment for a person who is addicted to the use of drugs or substances generates a series of different challenges.

First, it is necessary to detect if the person is intoxicated or under the effects of abstinence at the time of the aid. If so, in many cases it will be necessary to first render medical help before starting the treatment. Once the need for immediate medical attention has been ruled out, the approach to addiction cases requires exploring the pattern of consumption (substances, quantities, frequency) in order to have a better understanding of the case and to detect if the patient’s life is in danger. In those cases where addiction and depression occur simultaneously, this indicator is even more important since the possible suicidal ideation characteristic of depressive disorder can be realized through consumption.

In many cases, it will be necessary to implement strategies aimed at stopping consumption, such as the establishment of contracts, token economy programs, or hospitalization, in the most severe cases. While in these cases it is also common to promote participation in support groups (as you would with only depressive participants), in the case of people with drug dependence is often necessary to also provide support in areas such as employment and housing.


1. World Health Organization (2017). Recovered from http://apps.who.int/iris/bitstream/10665/254610/1/WHO-MSD-MER-2017.2-eng.pdf?ua=1
2. AMERICAN PSYCHIATRIC ASSOCIATION (APA). (2013). Diagnostic and Statistical Manual of Mental Disorders. Washington, USA.
3. Beck, A. (1967). Depression: Clinical, Experimental, and Theoretical Aspects. University of Pennsylvania, Philadelphia.
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10. David, D., Catalano, R., Georjeanna, W. (1994). Depression and Unemployment: Panel Findings from the Epidemiologic Catchment Area Study. American Journal of Community Psychology. 22 (6), 745-765.
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13. Grant, B. (1995). Comorbidity between DSM- IV drug use disorders and major depression: Results of a national survey of adults. Journal of Substance Abuse, 7 (4), 481-497.