Ann M. Guthery
Often primary care providers have adolescents brought to their office with complaints of irritability, decline in school performance, oppositional defiant behavior, withdrawn behavior, and somatic complaints. Deciding whether these symptoms are indicators of depression or are reflective of normal developmental transitions can often be difficult. Determining the persistence, intensity, and impairment caused by these symptoms with regard to home, school, and peers is needed to make the diagnosis of depression.
1. Identify symptoms of depression in adolescents.
2. Discuss treatment options including medication management and therapy in setting up a treatment plan.
3. Identify when a referral should be made.
Case Presentation and Discussion
Tom Williams is a 14-year-old male who is brought in by his mother who is concerned about his decreased energy level, frequent headaches, and stomach pains. He often wants to sleep or be alone in his room. He loses his temper easily and at one point punched a hole in the wall after an argument with his father. He just started ninth grade and is struggling with the transition to high school. He used to play baseball, but recently has been ditching his old friends and hanging around with new friends that his mother believes are a bad influence. Since being with these new friends, he has been caught shoplifting cigarettes and one of the peers was suspended for bringing marijuana to school. His mother is worried that he is using drugs, but he denies that he has used any.
You observe during this interaction that Tom’s affect is flat and he is tearful as his mother tells you this information. He has dark circles under his eyes and states, “I just don’t feel good, I can never get to sleep so I’m tired all the time and everything in my life is bad.”
You ask his mother to wait in the waiting room so you can question Tom privately. After his mother leaves he tells you the following:
He has tried marijuana a few times because he wanted to see if it helped him to relax, but he often feels worse after he comes off the high, so has stopped using it. He states he has felt sad for the last year; he often feels that no one likes him and that everyone judges him. His closest friend from the baseball team has a girlfriend whom he spends all his time with, so Tom has had to try and find other friends. He knows that the new friends are not considered the best behaved kids in school, but they at least cause some excitement in his life because he is always bored. He feels he can’t ever please his parents because he struggles with academics. He states his parents make him so angry that he feels like he wants to hit them when they are lecturing him for something he has done. He denies suicidal thoughts, but states he feels like he is in a hole and can’t crawl out of it. Every day is the same and nothing ever gets better.
In meeting with Tom’s mother, you find out that she and Tom’s father have been arguing and they have discussed a trial separation and possible divorce. Tom is an only child. His father is diagnosed with bipolar disorder.
What other things do you need to do to further assess this patient?
Before answering this, here is additional information you need to consider.
Description and Etiology of Depression in Children and Adolescents
Definition and Characteristics of Depression
A definition of childhood depression is difficult to find in literature because depression is usually described by symptoms. Depression in children and adolescents may be defined with the same criteria as for adults. It is based on negative cognitions such as hopelessness, negative view of the self, negative self-schema, negative attributions, loss of locus of control, and cognitive distortions. Depression is hard to diagnose in children because many also have comorbid diagnoses such as anxiety. Depression in children appears to be a syndrome with a combination of dysphoria (inappropriately or excessively sad mood) or anhedonia (loss of pleasure in response to previously enjoyed activities) as the two most significant symptoms.
Depression symptoms change with age. For example, in preschool children, decreased appetite, failure to gain weight, sad appearance, irritable mood, feeling bored, GI upset, sleep difficulties, and repetitive behaviors are the most common symptoms. They tend not to report depressed mood or hopelessness feelings (Hankin, 2006). In children ages 3–8 years, aggression and self-endangering behaviors are more common. Negative life events sometimes lead to depressive symptoms in early childhood while a negative explanatory style leads to depressive symptoms in later childhood and adolescence. Major depressive disorder in young people continues into adulthood across many studies (Hankin, 2006; Rice, Harold, & Tharper, 2002). Genetic and biological factors also have been found to contribute to the occurrence of depression in children.
Norepinephrine and serotonin are the two neurotransmitters most often implicated in mood disorders. People who are depressed have decreased sensitivity of beta adrenergic receptors for both epinephrine and serotonin; these neurotransmitters are increased with use of antidepressants. In addition to the neurotransmitters, studies have shown that the following areas of the brain are involved with mood regulation: medial and orbital prefrontal cortex, anterior cingulated cortex, amygdale, nucleus accumbens, and hypothalamus (Sadock & Sadock, 2007).
Depression commonly occurs with other mental disorders including anxiety, conduct/oppositional defiant disorders, and attention deficit hyperactivity disorder (ADHD). Eating disorders and substance abuse are associated with depression in adolescents (Hankin, 2006). In examining comorbid conditions in adolescents, Rice et al. (2002) found that chemical dependency could be a form of depression.
Mesquita and Gilliam (1994) reported that both attention deficit disorder and depression can result in difficulty with concentration, psychomotor agitation, and engagement in self-endangering behaviors. Social withdrawal, guilt, weeping, and dysphoria are key to depression. Thus, it is clear that depressed children are suffering and that their emotional and social well-being and academic progress are at risk.
Depression in Children and Their Families
Depressed children may have a depressed parent. In addition, they may have received hard power-assertive discipline, a rigid and inflexible family structure, and internalized aggression. A family interaction of low conflict and aggression and maternal aversiveness was seen in both depression and conduct disorders. Environmental stressors seem to be less correlated with depression.
Theories of Depression
According to Sadock and Sadock (2007), the causal basis for mood disorders is not known, but many theories have been proposed. These theories have been divided according to biological, genetic, and psychosocial factors, as well as cognitive theories.
It is important to understand that brain chemistry may affect perception and thinking, which in turn could impact mood. One hypothesis is that mood disorders are associated with heterogeneous dysregulation of the biogenic amines; in particular, depleted levels of serotonin and norepinephrine are most often implicated in mood disorders. The pathology for depression seems to occur in the limbic system, the basal ganglia, and the hypothalamus.
Genetic factors for depression have been shown in first-degree relatives. Sadock and Sadock (2007) cited a review of genetic studies showing that children have a 25% higher chance of developing a mood disorder if they have one parent with a mood disorder. If both parents have a mood disorder, then children have a 50–75% chance of developing a mood disorder. Key findings from a review of studies by Rice, Harold, and Tharper (2002) showed an increased familial risk, and that recurrent prepubescent major depressive disorder may be more familial than previously thought.
Psychosocial factors related to depression include life events and environmental stressors such as early loss and abandonment affecting children’s mood. Children who have experienced these stressors can show symptoms of internalized hostility, ambivalence, and loss of self-esteem. These factors can all affect thinking and perception, which, in turn, may be related to depressed feelings.
The cognitive theory of depression has been widely studied. According to this theory, depression results from a negative cognitive set (i.e., a tendency to erroneously view the self, future, and one’s experience in a negative manner). Basically, the model reveals that a loss of social reinforcement and disruption of close interpersonal relationships mediate the development and maintenance of depression symptoms; the less interpersonal competence one has, the greater the negative impacts on others and the poorer interpersonal problem-solving performance will be.
Stress and Coping
It is important to understand potential resources for coping because they may be spiritual in nature or they may function in place of spiritual resources for the child. People learn modes of coping from their membership group. Coping involves modification of the stressful situation, modification of the meaning of the problem in order to reduce stress, and then management of the stress symptoms. It includes specific behaviors that vary depending on the problem and the social role one is dealing with. However, coping has its limits. As Pearlin et al. (1981) explained, individuals, faced with an array of problems and hardships as they move through life, do not choose between coping and supports, but use both in an effort to avoid, eliminate, or reduce distress.
Epidemiology of Depression
Prevalence rates vary across studies, which use a variety of measures to identify depression. Twenty-eight percent of the students nationwide completing the Youth Behavior Survey (Centers for Disease Control and Prevention [CDC], 2008) reported feeling so sad or hopeless every day for two or more weeks that they changed their activities; 14.5% reported considering suicide, 11.3% had made a suicide plan, and 6.9% had attempted suicide. In an assessment of children with chronic emotional, behavioral, or developmental problems completed in 2001, 43.5% had depression or anxiety problems (CDC, 2005). Hankin (2006), in his review of many adolescent depression studies, notes that between 20% and 50% of adolescents report subsyndrome levels of depression. Generally, studies of individuals with clinically diagnosed major depression report prevalence rates of about 14% for 15 to 18 year olds and about 16.6% for 18 to 29 year olds. In childhood, rates are more like 1% to 3%.
What instruments could you use in your practice to assist in the diagnosis of depression in children?
In order to complete a full assessment and evaluation of an adolescent for depression, the healthcare provider will need to integrate information from multiple sources. Children and adolescents tend to be reliable in reporting internal symptoms, whereas parents and teachers are more reliable in reporting external symptoms. It is important to interview both the adolescent and the parents separately. Often, use of a screening questionnaire can help in guiding the interview. The Children’s Depression Inventory is one such tool (Kovaks, 2003). This is a 27-item symptoms-oriented scale designed for children and adolescents ages 7–17 years. Questions focus on severity of depression symptoms in the last 2 weeks. Whether using a questionnaire or an interview strategy, questions for adolescents need to focus on the following:
• Mood: Does the adolescent feel sad, down, irritable, or grouchy? Does the teen feel this way most of the time? Does he or she often cry? Does the teen get into more arguments with others recently, including parents, teachers, or peers?
• Anhedonia: Is the teen able to enjoy things he or she used to enjoy? Does he or she have less interest in doing fun things, often feel bored and tired, or have less energy than usual?
• Guilty feelings or negative self-image: Does the teen feel bad about him- or herself or feel bad about things they have done? Does the young person feel worthless? Does the teen have any friends and feel that other kids like them?
• Neurovegetative signs: Have changes occurred in sleep patterns—not able to sleep, waking up more, sleeping all the time? Are there changes in appetite—increased or decreased? Are there difficulties concentrating in school? Have grades dropped? Does the child or teen not want to go to school because it takes too much energy?
• Somatic symptoms: Does the boy or girl have headaches, stomachaches, or body aches? How often and how severe?
• Suicidal ideation: Has the child or teen wished to be dead or made a comment that they wished they were not here? Does he or she have any plans for self-harm? How detailed is the plan? What are the means? Has the youth tried to hurt him- or herself? How long ago did these feelings arise? What was going on when these feelings arose?
• Substance use: Is the youth using any drugs or alcohol, and if so, which ones? For how long? How much? Is this a recent change?
Questions for parents encompass similar areas:
• Mood/affect: How do they see the child’s mood? Has it changed recently? Is the child sad, angry, irritable? Is he or she arguing more? Does he or she avoid doing things he or she used to enjoy doing? Is he or she more withdrawn?
• Neurovegetative signs: Have they noticed changes in the child’s sleep patterns? Difficulty getting and staying asleep? Sleeping more? Any changes in appetite? Increased or decreased? Weight changes? Changes in energy level?
• Suicidal ideation: Has the child voiced any thoughts about wishing he or she was dead? Has the child tried to hurt him- or herself? Are they worried that the child may harm him- or herself? Have they seen that the child is preoccupied with death? Is he or she listening to, writing, or watching more morbid things?
• Impaired school or peer functioning: Have the child’s grades declined? Is the child showing less interest in social or after-school activities? Has the child missed a lot of school from not feeling well? Is he or she spending less time with peers? Has the peer group changed?
• Drug abuse: Are there any signs of substance use (e.g., lethargy, hyperactivity, hypervigilance, deviant or risk-taking behavior, absences or suspension from school, poorer school performance, withdrawal from family or friends, changes in friends, angry outbursts)? Tom scores positively for depression on the Children’s Depression Inventory which you administer in the office. This instrument validates the history that you obtained earlier.
Physical Examination and Laboratory Studies
What physical examination data should you collect?
As a primary care provider, it is important to complete a physical exam and laboratory screenings to rule out any physical causes for these symptoms, such as anemia; vitamin B12 deficiency; Cushing syndrome; connective tissue disorders such as juvenile arthritis or lupus; diabetes mellitus; chronic fatigue syndrome; fibromyalgia; hypothyroidism; infections such as mononucleosis, hepatitis, or human immunodeficiency virus (HIV); inflammatory bowel disorder; multiple sclerosis; seizure disorder; or tumors (Kaye, Montgomery, & Munson, 2002). Tom’s physical examination, including a careful neurological examination considering his headaches, is normal for his age.
Are any laboratory studies indicated for initial diagnosis and screening of depression in children?
Laboratory screenings for thyroid abnormalities, CBC, and toxicology are important. No abnormalities were found on the screening lab work for Tom.
Could these symptoms be the result of medication use?
A thorough history of use of other medications is needed. Steroids, thyroid supplements, megavitamins, benzodiazepines, beta-blockers, clonidine, Accutane, and oral contraceptives, for example, can all contribute to mood changes. Tom has not taken any medications or substances.
In addition, it is important to rule out ADHD, bipolar disorder, substance use/abuse, and anxiety disorders.
Making the Diagnosis
The results from the history, the positive results of the Childhood Depression Inventory, and data from both Tom and his parents lead you to make a diagnosis of depression. There is no indication of drug use or chronic illness, physical examination data to support a physical illness, or laboratory work indicating physical ailments that might account for his feelings. He has not had suicidal thoughts or other thoughts about harming himself or others.
As a primary care provider, you want to refer Tom to a mental health specialist for care. However, you also have a role to play in advocating for mental health treatment and arranging for a referral, and need to be acquainted with the care the mental health specialist will provide.
The following are actions you can expect from the mental health specialist that you can support (Kaye et al., 2002):
• Review stressors and contributing factors to mood changes.
• Clarify coping strategies that the patient and family have to support the adolescent’s capacity to discuss their feelings.
• Destigmatize the acknowledgement of emotional difficulties.
• Normalize developmental struggles.
• Identify self-esteem–enhancing activities and skills such as any school-based activities, sports, or camps.
• Reinforce good self-care habits. (Establishing regular eating, sleeping, and exercise habits help mental health.)
• Rule out maltreatment as a contributing factor.
• Educate the teen and family about signs of increasing depression such as sleep disturbances, changes in appetite, school problems, and argumentativeness.
Cognitive Behavioral Therapy
Psychotherapy is used for mild cases of depression. The largest randomized clinical trial for adolescent depression, the Treatment of Adolescent Depression Study (TADS) (March et al., 2004) showed that moderate to severe adolescent depression is best treated with a combination of an antidepressant and cognitive behavioral therapy (CBT). Other studies demonstrate the effectiveness of CBT (Compton et al., 2004; Hazell, 2004; Powers, Jones, & Jones, 2005).
CBT is often the therapy of choice because depression is considered a cognitive dysfunction. CBT is based on the assumption that the way a person thinks, perceives, and actively interacts within the environment determines his or her feelings and behaviors (Beck, 1976). An individual’s emotions and behaviors are, in large part, determined by the way in which he or she cognitively appraises the world. The primary care provider who understands basic CBT concepts can better support the mental health specialist’s work.
CBT can be understood best as an integrated theory that links cognitive, affective, social, and developmental processes to behavior. An individual’s cognitions are termed schemas and are central to thought and perception. They have a fundamental influence on emotion and behavior and can be either positive or negative. They help process and organize complex information into meaningful patterns over time (Beck, 1976).
Beck’s theory takes into account metacognitions, which are defined as “thoughts about thinking” that emerge during middle childhood. It is at this time that children become more skilled in identifying information needed to solve problems. The development of metacognitions is necessary for the child to develop a sense of self. By 8 years of age, children have been found to distinguish between thoughts and behavior (Flavell, Green, & Flavell, 2000; Quakley, Coker, Palmer, & Reynolds, 2003).
The goal of CBT is to decrease negative schema and their emotional and behavioral consequences. This is done by: 1) assisting the individual to attempt new behaviors and experiences; 2) acknowledging the individual’s past but focusing the intervention on the present desired functioning; 3) viewing the changes in emotions and behavior from both an objective and subjective vantage point; 4) refocusing the individual on recent successful experiences; and 5) redirecting the self-evaluations to reasoned depictions of positive perceptions, beliefs, and attitudes. Problems that are brought to the therapy appointment are broken down into a series of questions, the answers to which gradually reveal the solution. In the session, the teen is asked to begin to question his or her own reactions. For example:
• What other plausible perspective(s) can I take about this matter?
• What factual evidence supports or refutes my beliefs?
• What are the pros and cons of continuing to see things the way I see them, and what are the pros and cons of trying to see things differently?
• What constructive action can I take to deal with my beliefs or schemas?
• What sincere advice would I give to a good friend with the same beliefs?
In any type of therapy it is difficult to understand numerous problems in their entirety. CBT focuses on individual events or problems and allows the therapist to conceptualize connections and solutions. A prioritization needs to occur in CBT, as follows: First, assess and problem solve for suicide risk. Next, address interfering behaviors such as homework noncompliance, medication noncompliance, not working collaboratively in therapy, and missing appointments. Third, address behaviors that are dangerous and that interfere with quality of life such as substance abuse, shoplifting, high-risk sexual behaviors, abusive relationships, or homelessness. These behaviors have to be addressed first or no progress can be made.
Goal setting must be mutually agreed on. The goals should be described concretely and with measurable outcomes. The therapist is trying to teach goal-oriented active problem-solving skills focused on concrete, specific patient problems. Other names for CBT have included goal setting, problem solving, self-statement modification, social perception skills training, self-control training, and cognitive restructuring. Over time, CBT can help the teen to recognize themes that identify specific maladaptive automatic thoughts.
In clinical practice, evaluation of the existing knowledge and beliefs of the individual are determined, appropriate interventions are developed to educate and motivate, and the resulting behavior changes are appraised.
For CBT, a “thoughts log” like that shown in Table 14-1 could be used to help the teen change his or her thinking.
Often psychotherapy is used first for mild cases of depression. Medications may be warranted if this is not effective, or if the depression is more severe. Selective serotonin reuptake inhibitors (SSRIs) are considered the first-line treatment for depression. Food and Drug Administration (FDA) approved indications for pediatric depression controlled trials support the use of fluoxetine (Prozac), paroxetine (Paxil), and citalopram (Celexa) for children and adolescents with depression. Open trials also support the use of Prozac, sertraline (Zoloft), Paxil, Celexa, and fluvoxamine (Luvox). With respect to dosing of these medications, the rule of thumb is to “start low and go slow.” Dosing can be increased every 5–7 days to target dose and then should be held for 4–6 weeks before further dose increases. Table 14-2 shows dosing guidelines. Medications are typically given on a QD (daily) schedule. The primary care provider may be asked by the mental health specialist to prescribe psychotropic medications if that person does not have prescriptive authority. Even if not prescribing, the primary care provider needs to know which medications are being prescribed and provide surveillance related to safety and effectiveness.
Table 14–1 Thoughts Log
When prescribing, it is important to educate patients about side effects because this seems to help with treatment adherence. Common side effects of SSRIs include agitation or restlessness, apathy or amotivation syndrome, gastrointestinal upset or diarrhea, headaches, insomnia, and sexual side effects (Kaye et al., 2002).
Serotonin syndrome is a serious and possibly fatal syndrome that occurs when serotonin has been overstimulated. Symptoms include diarrhea, restlessness, extreme agitation, hyperreflexia, and autonomic instability with possible rapid fluctuations in vital signs, myoclonus, seizures, hyperthermia, uncontrollable shivering and rigidity, delirium, coma, status epilepticus, cardiovascular collapse, and death. Treatment includes removing the offending agent and referral to the hospital for care (Sadock & Sadock, 2007).
Table 14–2 Dosing Table for SSRIs
SSRIs and Side Effects
If intolerable side effects emerge or a maximal dosage is reached without improvement after 8–12 weeks, then an alternative SSRI should be cross-tapered and substituted. If a second SSRI trial is unsuccessful, then atypical antidepressants (bupropion, venlafaxine, mirtazapine, and duloxetine) can be tried, although it is important to note that fewer data are available on these agents. Bupropion (Wellbutrin) has stimulant-like properties and has been helpful in some adolescents with symptoms of depression and ADHD. It has been associated with increased risk of seizures and should not be used in patients with a history of substance abuse or eating disorders because it is contraindicated in these cases. Venlafaxine (Effexor) has also been shown to help symptoms of depression and anxiety in adolescents. It can cause blood pressure elevations, and 5–7% of patients on it must be monitored for these changes. Mirtazapine (Remeron) has not been used widely in adolescents. It is highly sedating and, rarely, is associated with agranulocytosis. Duloxetine (Cymbalta) also has not been widely used for adolescents, but is available. Adult data show gastrointestinal side effects. Tricyclic antidepressants are not currently supported as first-line agents for treating juvenile depression. Studies have shown that they have a narrow margin for safety and lack of benefit (Kaye et al., 2002; Sadock & Sadock, 2007).
When adolescents are taking antidepressants, the healthcare provider needs to be vigilant for signs of mania, including increased activity, irritability, aggression, euphoria, giddiness, and decreased need for sleep. If these symptoms are present the antidepressant needs to be discontinued. This can occur with use of any of the antidepressants in adolescents predisposed to bipolar disorder (Sadock & Sadock, 2007). Suicide ideation can also occur.
Both adolescents and their families need to be reminded that antidepressants often take 2–4 weeks to alleviate symptoms. The medication should be continued for 6–12 months once symptoms improve. Adolescents should be symptom-free for at least 3 months before considering tapering off of medication. Antidepressants need to be slowly tapered. This will prevent withdrawal symptoms and allow for rapid retitration if depressive symptoms reoccur (Sadock & Sadock, 2007).
In Tom’s case, it would be appropriate to start Prozac 10 mg 1 tablet PO in the morning and refer him to a therapist for CBT. It would be important to have him return weekly for 2 to 4 weeks for follow-up to report on how he is feeling and to assess for suicidal ideation.
What will you do to educate him and his mother about depression and the management of his symptoms?
The following are points you include when educating Tom about depression and it’s management:
Explain the diagnosis and its pathophysiology, its chronic nature, and the need for medications and therapy to stabilize the depressed mood.
Explain the use of the antidepressant prescribed, including efficacy and side effects. Reassure them that the medication may not result in improvement for 4–6 weeks and that the improvement may seem subtle. Often parents and teachers will notice the benefit before the teen may feel it.
Discuss monitoring for suicidal ideation and that it is important for Tom to tell his parents if he has these feelings. Tom or his parents should call you immediately so it can be determined if he might need to be hospitalized at that point.
Explain your process to arrange for a mental health specialist to see Tom for therapy and your intention to call the therapist to work out a plan to coordinate management as specialist and primary care provider.
Once his mood is stable, follow-up appointments can be changed to meeting every 4–6 weeks to continue to assess response to medications and to support the patient and his parents. In our case example, Tom begins to feel better after 4 weeks on Prozac. He has started to see a therapist and is starting to work on viewing situations in his life more positively. After 6 months of therapy and medications, he is enjoying high school, his grades have improved, and he is more motivated and has his sense of humor back. He has started to play baseball again and is hanging out with more positive peers. No suspicions of drug use are noted.
Key Points from the Case
1. Guidelines can help to simplify the care of depression, such as how to choose a medication or therapy technique, but often the individual’s situation and variables of biology, environment, cognition, and events leading to depression all need to be factored into treatment planning.
2. Treatment of depression with a teen includes understanding his or her pathophysiology, cognitive development, family history, family environment, school environment, social environment, and life experiences.
Beck, A. (1976). Cognitive therapy and emotional disorders. New York: International Universities Press.
Centers for Disease Control and Prevention. (2005). Mental health in the United States: Health care and well being of children with chronic emotional, behavioral, or developmental problems—United States, 2001. Morbidity and Mortality Weekly Report, 54(39), 985–989.
Centers for Disease Control and Prevention. (2008). Youth risk behavioral surveillance—United States, 2007. Morbidity and Mortality Weekly Report, 57(SS-4).
Compton, S., March, J., Brent, D., Albano, A., Weersing, R., & Curry, J. (2004). Cognitive-behavioral psychotherapy for anxiety and depressive disorders in children and adolescents: An evidence-based medicine review. Journal of the American Academy of Child and Adolescent Psychiatry, 43(8), 930–959.
Flavell, J. H., Green, F., & Flavell, E. R. (2000). Young children’s knowledge about thinking: Monographs of the Society for Research in Child Development. Malden, MA: Blackwell.
Hankin, B. (2006). Adolescent depression: Description, causes, and interventions. Epilepsy and Behavior, 8, 102–114.
Hazell, P. (2004). Depression in children and adolescents. Clinical Evidence, 12, 427–442.
Kaye, D. L., Montgomery, M. E., & Munson, S. (2002). Child and adolescent mental health. Philadelphia: Lippincott Williams & Wilkins.
Kovaks, M. (2003). Children’s Depression Inventory: Technical manual. Toronto: Multi-Health Systems.
March, J., Silva, S., Petrycki, S., Curry, J., Wells, K., Fairbank, J., et al. (2004). Fluoxetine, cognitive behavioral therapy, and their combination for adolescents with depression: Treatment for Adolescents with Depression Study (TADS) randomized controlled trial. Journal of the American Medical Association, 292, 807–820.
Mesquita, P. B., & Gilliam, W. S. (1994). Differential diagnosis of childhood depression: Using comorbidity and symptom overlap to generate multiple hypotheses. Child Psychiatry and Human Development, 24(3), 157–172.
Pearlin, L. I., Lieberman, M. A., Menaghan, E. G., & Mullan, J. T. (1981). The stress process. Journal of Health and Social Behavior, 22, 337–356.
Powers, S., Jones, J., & Jones, B. (2005). Behavioral and cognitive-behavioral interventions with pediatric populations. Clinical Child Psychology and Psychiatry, 10, 65–77.
Quakley, S., Coker, S., Palmer, K., & Reynolds, S. (2003). Can children distinguish between thoughts and behaviors? Behavioural and Cognitive Psychotherapy, 31, 159–168.
Rice, F., Harold, G., & Tharper, A. (2002). The genetic aetiology of childhood depression: A review. Journal of Child Psychology and Psychiatry, 43(1), 65–79.
Sadock, B. J., & Sadock, V. A. (2007). Kaplan and Sadock’s synopsis of psychiatry (10th ed.). Philadelphia: Lippincott Williams & Wilkins.