A New Pandemic of the XXI Century: The Growing Crisis of Adolescent Depression in the Digital Age

Introduction

Depressive disorders in the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) encompass the diagnoses of major depressive disorder (MDD), disruptive mood dysregulation disorder (DMDD), persistent depressive disorder-dysthymia (PDD), and depression not otherwise specified [1]. According to WHO 2014, “youth” are people aged 10–19 years [1]. Adolescent depression is an increasingly common disorder and constitutes a significant health problem, as over the years there has been a sharp increase in the number of hospitalizations of young adults and adolescents [2]. Modern lifestyle, a huge number of stimuli and stressors, and increased susceptibility to them contribute to the increased incidence of depression [3]. Adolescence is a period in a young person’s life characterized by numerous changes in the neuropsychology of the brain at the structural and emotional levels [3]. This is a period that is highly sensitive to stressors, such as stress, neglect, or isolation, when the hormonal system also undergoes many changes that are crucial for growing up [4]. To provide teenagers with the best possible development conditions, which will later translate into their adult life and the choices they make, it is worth paying particular attention to the documented causes their mental problems, the diagnosis and symptomatology of adolescent depression, and the possibilities of its treatment and rehabilitation. The annual incidence rate of depression in children aged 13 years is 1–2%, and in children aged 15 years it is 3–7% [1]. These data emphasize that this is a leading and important problem of modern medicine. It is worth expanding public awareness due to the scale of prevalence and significant consequences of this disorder in the age group in question. According to numerous publications, major depressive disorders are the most common cause of disability in the group of adolescents aged 10–19 years [1]. Research confirms that the occurrence of early-onset depression is associated with a worse prognosis for the further course of the disease [5], with high relapse rates and poorer cognitive functioning [6]. The present report focuses on the psychosocial conditions, clinical features, and forms of therapy for adolescent depression. For this purpose, the PubMed and Google Scholar databases were searched by entering the keywords “adolescent depression.” Therefore, this article aims to review the causes and consequences of the increasing incidence of depression, self-harm, and suicide among children and young people, and current management approaches.

Incidence, Causes, and Consequences of Depression

ETIOLOGY OF ADOLESCENT DEPRESSION:

The etiology of depressive disorder in adolescents is multifactorial. Genetic and environmental factors contribute to the development of depressive symptoms. One of the most important risk factors for developing depression is a family history among first-degree relatives. Studies have confirmed that the risk of depression in the offspring of depressed parents is 2–4 times higher than in the offspring of healthy parents [1]. Moreover, the influence of genes on is also emphasized by analyses of the serotonin transporter gene variant (5-HTTLPR), which may increase the risk of depression in the event of adverse life events, including early abuse [1]. This may constitute an interesting turning point in deepening knowledge about the etiology of adolescent depression. High-intensity stress in early life may cause serious disturbances in gene expression due to epigenetic mechanisms [3]. This process translates directly into the occurrence of mental health anomalies later in life. Research confirmed that people experiencing extremely strong stressors were more likely to develop major depressive disorder before the age of 18 years [3]. Moreover, it is believed that gender also determines the strength of the impact of stress on young people – mental health problems appear more often in young women than in young males, while men were more likely to use psychoactive substances [3]. Currently, there is not enough research to confirm the impact of stress and its nature at a young age on epigenetic changes in adolescents. One opportunity is a genome-wide association study, based on examining the relationship between the frequency of single nucleotide polymorphisms and the occurrence of depression [3,7].

There are many risk factors for development of depression in teenagers, but psychosocial and biological factors play a key role. The first group includes, among others, neglect, violence, sexual abuse, and severe stressful experiences such as the loss of a loved one. The second is depression in family members, hormonal storm during adolescence, organic diseases such as diabetes, female gender, and the use of certain medications [4]. Significant external stressors also include poverty in the family home and being raised by a single parent [6]. The role of rejection by peer society in the development of depression and even trauma with manifestations of post-traumatic stress syndrome symptoms is also emphasized [6]. All these situations can lead in adult life to significant disturbances in functioning in society, social anxiety, and exclusion from social life. Only early diagnosis and treatment of depression will prevent the serious consequences of this disease.

The ecological systems theory proposed by Bronfenbrenner (1992) highlights the function of the various environments in which adolescents develop [6]. The micron system, 1 of the 5 distinguished in this theory, has the greatest impact on the young individual. It consists of the home environment, school environment, and the peer group, which consists of groups that surround young people every day and have a constant impact on the functioning and experience of a young person’s everyday life. The more supportive this system is, the greater the chances of proper development and resistance to negative stimuli [6].

THE INFLUENCE OF MASS MEDIA, COVID-19, AND THE CO-OCCURRENCE OF OBESITY:

With the constant development of civilization, the use of social media from an early age is becoming more and more common. Among people aged 13–17 years, 97% actively participate in interactive social life [4]. In the case of girls who use the Internet intensively, the risk of developing serious depressive symptoms was 166% higher compared to those who rarely use the Internet [8]. The above facts show how many threats are posed by uncontrolled use of the Internet by young people – from abandoning social life in real life and the lack of ability to create social relationships, through increased pressure and constant comparison, to cyberbullying and addiction [4].

According to research, exceeding the threshold time of 3 h spent on the Internet has a negative impact on many young users; worsening mood and shortening sleep, leading to depression and anxiety disorders [8].

To better understand the correlations between the COVID-19 pandemic and disruption of mental life of people going through adolescence, the importance of peer contacts during this period should be emphasized [9]. At this time, acceptance by peers becomes crucial for young people, which correlates with the increased impact of these interactions on the teenager’s well-being. During the outbreak of the pandemic, restrictions on movement and distance learning significantly limited maintaining interpersonal contacts, which are so important for young people. Recent studies have shown an increasing trend in the incidence of depression in teenagers after the outbreak of the COVID-19 pandemic [6]. During this period, the young generation was exposed to long-term isolation, death, and illness of loved ones, and excessive time at home with family members, whose pathological behavior could worsen [10]. In addition, previously treated mental illnesses may have become more acute and even lead to the development of post-traumatic stress syndrome in more susceptible people [10]. The long-term effects of the global crisis are still being investigated.

In recent years, increasing trends in the incidence of depression and obesity in children and adolescents have been noticed [7]. Both conditions are associated with inflammation in the body and it has been proposed to treat both disorders simultaneously to achieve the best possible results in the treatment of depression [7].

In the conducted research, visceral fat tissue becomes the most sensitive indicator of depression in adolescents and may be correlated with its severity. It also becomes a predictor of depression and not only a regional indicator of fat tissue assessment [7].

The pathophysiology of depression in adolescents is still not fully understood, but a theory that deserves attention is the disturbance of the hypothalamic-pituitary-adrenal axis and persistently elevated cortisol levels. Physical activity can help restore neurohormonal balance in the body. In the mechanism of movement, pro-inflammatory cytokines are inhibited and the concentration of growth factors necessary for neurogenesis is increased [11].

DIAGNOSTICS AND CLINICAL PICTURE OF ADOLESCENT DEPRESSION:

Symptoms of depression in adolescents are heterogeneous and its course differs from that in adults. It is recommended to grade treatment from the beginning and exercise caution at each stage: starting with short psychosocial activities, then psychological therapy, and finally pharmacological treatment [2].

According to the Diagnostic and Statistical Manual of Mental Disorders-5, to diagnose depression in the pediatric age group, the patient should present at least 5 symptoms for a period of at least 2 weeks, including depressed or irritable mood most of the day, almost every day, as evidenced by either a subjective report, such as the patient feeling sad, empty, or hopeless, or an observation made by others, such as the patient appearing sad.

Depression can manifest as significant loss of interest or pleasure in activities most of the day, almost every day, as indicated by self-reports or observations; failure to achieve expected weight gain or noticeable weight loss when not following the diet, or significant weight gain, or a decrease or increase in daily appetite, lack of sleep or excessive sleeping almost every day, almost daily anxiety or psychomotor retardation (observed by others, not just a subjective feeling of anxiety), lack of energy almost every day, feelings of worthlessness or inappropriate guilt (possibly delusional) almost daily (not just self-reported or guilt about illness); decreased ability to think, concentrate, or indecision, almost every day (either based on self-report or observed by others), recurring thoughts of death (not just fear of death), recurrent suicidal thoughts without specific plans; suicide attempt; or a specific plan to commit suicide.

These symptoms must significantly change the functioning of the young person, significantly disturbing individual areas of life. At the same time, to make a diagnosis of adolescent depression, other diseases that may influence the occurrence of the above symptoms must be excluded [1].

Identical diagnostic criteria are used to diagnose depression in both children/adolescents and adults, with 1 exception – irritable mood, not depressed mood, is considered one of the main symptoms in children [12]. It is interesting that vegetative symptoms, such as changes in sleep/wake rhythm, decreased drive and appetite, and changes in body weight, occur more often in teenagers than in adults. On the other hand, decreased concentration and anhedonia are more common in adults [12].

L1Incidence, Causes, and Consequences of Self-Harm and Suicide

According to American Foundation For Suicide Prevention, non-suicidal self-injury is a self-inflicted act that causes pain or superficial damage but is not intended to cause death. Diagnosing self-harm requires, first of all, excluding suicidal behavior. At the same time, before starting treatment, it is necessary to assess the self-injury, including type, frequency, duration, causes, assessment of the coexistence of other mental disorders, assessment of the risk of suicide attempt, and assessment of the patient’s willingness to cooperate. One meta-analysis showed a close relationship between the occurrence of depression and non-suicidal self-injury [13]. Globally, the estimated prevalence of self-harm in adolescents ranges from 14% to 30%, and in depressed adolescents the prevalence reaches 40% or higher [4]. Risk factors that increase the likelihood of self-harm include emotional instability, dysfunctional families as the basic social unit, and the experience of trauma in childhood [13]. Treatment is mainly based on psychotherapy (eg, cognitive behavioral therapy, dialectical behavioral therapy, group emotion regulation therapy). As a result of depression, suicide attempts and completed suicides occur. The American Foundation For Suicide Prevention determines suicide as death caused by an act of self-harm that is intended to be lethal. Suicidal behavior encompasses a spectrum of behavior from suicide attempt and preparatory behaviors to completed suicide. Suicidal ideation refers to the process of thinking about, considering, or planning suicide. Suicide is the third leading cause of death in the 10–19 age group [1]. Girls aged 15 years and over are more likely to suffer from depression and manifest suicidal thoughts and attempts, but the suicide rate is higher in adolescent boys [4]. Typical risk factors include identification with a sexual minority and family or individual history of psychiatric problems [14]. The initial stage of selective serotonin reuptake inhibitor (SSRI) pharmacotherapy leads to an increase in drive, with still depressed mood. This unfortunate correlation requires closer control and supervision of the patient at the beginning of treatment, because during this period suicidal thoughts may turn into attempts, often completed [15]. It is recommended to evaluate the effectiveness of treatment with SSRIs within 4–6 weeks of starting therapy, because in the initial stage of fluoxetine treatment, young patients have a greater risk of suicide [16].

Therapy of Adolescent Depression

The basic methods of treating adolescent depression are psychotherapy and pharmacotherapy.

In mild depression or in the presence of contraindications to pharmacotherapy, the primary intervention is psychotherapy alone [17]. Cognitive behavioral therapy (CBT) and interpersonal therapy (IPT) are 2 forms of therapy that constitute the basis in the treatment of depression [17]. The best described effects have been in patients over 13 years of age [17]. CBT is described in more detail in the literature, and it has had better results than IPT [17]. CBT is based on the freedom of cognitive restructuring and behavioral activation [17], and involvement of caregivers has a significant impact on its effectiveness [17]. IPT focuses on enriching problem-solving skills, improving communication, and strengthening relationships [17]. A less recognized trend in CBT is acceptance and commitment therapy, which also seems to be effective in adolescent patients, but is currently less widespread [17]. If the patient’s clinical condition does not improve or depression worsens despite psychotherapy, pharmacotherapy may be added to the treatment [17].

Studies show a smaller effect of psychotherapy in children and adolescents compared to adults [18], perhaps because therapies conducted with adolescents were initially designed for adults and were modified to work with young patients [18]. Another hypothesis is that the parents of minors still have a significant influence, as they may show a lack of support during children’s therapy and may even intensify the experience of destructive emotions [18]. In this situation, teenagers become defenseless and discouraged, giving up on the therapy they need so much.

Another hypothesis states that the effectiveness of treating depression with psychotherapy may not increase in a linear manner because it is low in children, then increases significantly in young adults and decreases again in adults [18]. This is an interesting phenomenon that is worth investigating in the future.

In terms of pharmacological treatment, selective serotonin reuptake inhibitors (SSRIs) are less effective in adolescents than in adults, but they remain the first-choice group of drugs for treating depression. The FDA (Food and Drug Administration) has approved only 2 drugs for use in adolescent depression – fluoxetine from the age of 8 years at an initial dose of 10–20 mg/day and escitalopram from the age of 12 years with an initial dose of 5–10 mg/d [17,19].

During therapy with fluoxetine – the first-line drug in adolescents suffering from depression – with high doses (60 mg/d), an increase in the frequency of completed suicides and the level of anxiety was observed [20]. Fluoxetine used in adolescent depression is associated with numerous adverse effects, so it is crucial to discuss the possibility of undesirable symptoms with the patient and parents, as this may result in discontinuing the drug and discontinuing the therapy. It seems crucial to divide adverse effects into transient and permanent ones, which may significantly increase patients’ awareness of treatment [21]. The first group includes gastrointestinal symptoms and excess body weight that appears later, and the second group includes sexual disorders, such as decreased libido [21].

The most sensitive aspect regarding adverse effects during SSRI depression therapy remains weight gain. An increased risk of overweight was observed during the use of paroxetine and citalopram, while during treatment with duloxetine (a drug from the group of serotonin and norepinephrine reuptake inhibitors), weight gain decreases with the duration of therapy [21]. The basic preventive measures are maintaining a balanced diet and regular physical activity.

It is also important to consider the increasing use of stimulants by young people, such as cannabis, which is also metabolized by cytochrome CYP2C19, like SSRIs, which may enhance the effect of antidepressants and cause diarrhea or dizziness, which can discourage treatment [21]. The pathomechanism does is unclear, but antihistamine activity and 5HT2C receptor activity seem probable [21].

In resistant depression (score >40 on the Revised Depression Scale for Children), intravenous ketamine may be started, which reduces the severity of symptoms as early as 24 h after administration and the effect lasts up to 14 days [22]. This drug has been proven to be more effective than midazolam and may constitute a breakthrough therapy in acute depression, not only in adults but also in pediatric patients (results confirmed using the MADRS scale) [22].

Another method is electrostimulation, which, especially in younger people, has a strong therapeutic effect [23], especially when the unilateral stimulation variant is used [23]. This method is not widely used due to insufficient research [23]. Moreover, there are no data on the recommended dose, frequency of sessions, or total duration of treatment [23]. However, this is undoubtedly an interesting starting point for the future in this group of patients, providing a chance for treatment without the need to use pharmacotherapy [23].

We should also not forget about the important role played by a strong bond with peers and support from family in treatment [4]. Such relationships have a documented impact on reducing the incidence of mental health problems and could even have a protective effect [4].

Neuroimaging and Transcranial Magnetic Stimulation

A 2022 study published in the International Journal of Neuropsychopharmacology appears to be the first to broadly cover the topic of neuroimaging in adolescents with depression [16]. The results obtained using magnetic resonance imaging confirm a reduced volume of the amygdala and the caudal part of the anterior cingulate cortex in depressed versus adolescents [16].

The cited article presents TMS (transcranial magnetic stimulation) as a promising therapy of choice for over one-third of adolescents suffering from depression resistant to SSRI pharmacological treatment [16]. TMS is an electromagnetic stimulation of the brain using a pre-cranial method in which a coil is placed on the surface of the head [24]. Analyzes of previous studies confirm the effectiveness of TMS therapy in younger people and in people with severe depression [24].

The authors emphasize, however, that changes in the anterior cingulate cortex remain non-specific for this disease and TMS treatment does not restore the volume of this brain structure [16]. On the other hand, high-frequency TMS in the left-prefrontal position significantly improved the results in the amygdala [16].

Future Directions

The worse prognosis of depression in young people requires early detection and use of appropriate screening tests such as the Kutcher Adolescent Depression Scale.

There is still no confirmation of the relationship between high-intensity stress experienced by adolescents and epigenetic changes. It is justified to continue genetic research based on genome-wide association studies to make breakthrough discoveries and confirm these theories.

Excessive use of social media by adolescents is associated with an increased risk of depression, and the number of hours spent at a computer correlates with the level of this risk. It is necessary to educate parents to increase awareness of this threat and, consequently, control their children.

From 2019, due to the onset of the COVID-19 pandemic and the research-confirmed increase in the incidence of isolation-related depression, primary care physicians should be more vigilant about the need for constant screening of patients for depression.

Analysis of visceral fat may become a new and useful indicator in detecting depression and determining its severity. More research is needed to investigate this correlation, allowing wider use of this indicator in the future.

Due to its high effectiveness and low risk of adverse effects, electrostimulation of the brain may become a leading method in the treatment of adolescent depression. Its widespread use is limited by insufficient knowledge among specialists and the small number of studies in this age group, as well as public stigmatization.

Results

Depression has many consequences for mental health, from worsening academic performance, through anxiety, substance abuse, to suicide attempts. Adolescents are exposed to this disease as they experience great stress during their development, which may have many different causes, such as neglect, mental and sexual violence, and loss of loved ones. However, the most threatening risk factor is still the family history embedded in the genetic code. The burden of lifestyle diseases, obesity, and autoimmune diseases at such a young age is also important.

The image of adolescent depression superficially resembles that presented in adults, but when delving deeper into this topic, the dominant group of symptoms in adolescents are those originating from the autonomic system.

The problem of self-harm and completed suicides remains a serious threat in adolescents; it is one of the main causes of death and can be prevented through early and effective interventions and adequate specialist help.

Treatment of adolescent depression is based on psychotherapy and pharmacotherapy and, in exceptional cases, electrostimulation. SSRIs, which are drugs of first choice, unfortunately produce less effective results than in adults and have numerous adverse effects, including gastrointestinal disorders and weight gain, which are often the reason for rejection of treatment by young patients. Therefore, it seems crucial to conduct a conscious, educational conversation with patients and their caregivers. The epicenter of helping a sick person is still support from their loved ones.

Adolescent depression is undoubtedly a leading medical problem in the adolescent age group, which is reflected in the statistics of the disease and related self-harm and suicides. Currently, the most documented risk factor for the disease is a family history of suicide by a first-degree relative. Nowadays, however, the growing number of cases of depression in teenagers is also increasing, largely due to the abuse of social media and the COVID-19 pandemic, as well as co-existing obesity, which increases inflammation in the young person’s body. The clinical picture is dominated by vegetative symptoms and an irritable mood, which distinguishes the course of this disease from that of adults. The most dangerous effects of depression remain self-harm, suicide attempts, and completed suicides. An indispensable duty of a specialist is special monitoring of patients, as after starting SSRI therapy young people tend to have an increase in drive and risk of committing suicide. The treatment of depression in adolescents requires innovation to improve the effectiveness of previously unsatisfactory results. Particularly noteworthy is the method based on TMS, which is a very attractive alternative to pharmacotherapy because it has high effectiveness and few adverse effects.