Depression Through Childhood Development

Early theories of depression assumed that infants and children could not experience depression. A common current misperception of depressive symptoms in children is that they represent a phase that children will “grow out of” with time. Research demonstrates that depression may manifest as early as infancy and that early depression may recur or persist into later developmental stages. New research is focusing upon issues of prevalence, etiology, diagnostic criteria, stability of diagnoses over time, comorbidity, and treatment. [Zalsman: 2006]

Depressive symptoms in infants may include sadness, inactivity, withdrawn behavior, agitation, sleep problems, feeding problems, or failure to thrive. A major controversy is whether symptoms may occur endogenously or are always associated with environmental stress (separation from caregivers, maternal depression, neglect, abuse, severe illness). Such symptoms should prompt a search for environmental causes or physical illness. Diagnostic criteria for depression in infancy are available (Diagnostic Classification of Mental Health and Developmental Disorders of Infancy and Early Childhood, Revised (DC:0-3R)). The proper diagnosis and treatment of such cases demand referral to a specialist. There are no data on treatment in this age group.

Preschoolers may also present with depressive symptoms which may include those listed above for infants, as well as the child’s stated emotions (e.g., “I’m sad”) or observation of depressive themes in the child’s play (e.g., themes of sadness, loss, guilt, aggression, death, or suicide). Somatic symptoms (e.g., headaches, stomachaches) may be present but are less frequent than more typical depressive symptoms. [Luby: 2003] Endogenous depression is less controversial in this age group, but environmental factors are still important to consider. Prevalence is uncertain but may be as high as 1 percent. [Stalets: 2006] As with infant depression, diagnostic criteria are available that have been modified to reflect developmental stage and include decreased number and duration of symptoms. [Luby: 2003] No data exist on treatment in this age group.

There is little controversy regarding the existence of endogenous depression in school age children, with a prevalence of 1-2 percent and a 1:1 male to female ratio. [Costello: 2003] Diagnosis is based on DSM-IV criteria. These are unmodified from adult criteria save for the inclusion of irritable mood in addition to depressed or sad mood. School age children are more able to report their own symptoms. Often symptoms reported by the child may be combined with those reported by caregivers to arrive at a diagnosis. School dysfunction may be a strong indicator for the need for evaluation. There are positive research findings for use of medications and cognitive behavioral therapy (CBT) in this age group.

The prevalence of depression in adolescence jumps to 3-8 percent. [Costello: 2003] The sex ratio changes as the prevalence in girls increases relative to boys, resulting in a 2:1 female to male ratio that persists until late middle age. Pubertal hormonal and physiologic changes undoubtedly play a role but research has not yet defined causal factors. [Angold: 2006] Diagnosis is by DSM-IV criteria and often can be made by interview with the adolescent alone, though it is strongly recommended to interview both the adolescent and their caregivers. School dysfunction may be a clue to depression. Social withdrawal or changes in friends may also be a clue, as may new onset of arguing or defiant behavior at home. There are positive research findings in this age group for the use of medications, cognitive behavioral therapy (CBT), interpersonal psychotherapy (IPT), and electroconvulsive therapy (ECT).