The term complex trauma describes both children’s exposure to multiple traumatic events, often of an invasive, interpersonal nature, and the wide-ranging, long-term impact of this exposure. These events are severe and pervasive, such as abuse or profound neglect. They usually begin early in life and can disrupt many aspects of the child’s development and the very formation of a self. Since they often occur in the context of the child’s relationship with a caregiver, they interfere with the child’s ability to form a secure attachment bond. Many aspects of a child’s healthy physical and mental development rely on this primary source of safety and stability.
Many children with complex trauma histories suffer a variety of traumatic events, such as physical and sexual abuse, witnessing domestic and community violence, separation from family members, and revictimization by others. Complex trauma can have devastating effects on a child’s physiology, emotions, ability to think, learn, and concentrate, impulse control, self-image, and relationships with others. Across the life span, complex trauma is linked to a wide range of problems, including addiction, chronic physical conditions, depression and anxiety, self-harming behaviors, and other psychiatric disorders.
Beyond the consequences for the child and family, these problems carry high costs for society. For example, a child who cannot learn may grow up to be an adult who cannot hold a job. A child with chronic physical problems may grow up to be a chronically ill adult. A child who grows up learning to hate herself may become an adult with an eating disorder or substance addiction.
Children whose families and homes do not provide consistent safety, comfort, and protection may develop ways of coping that allow them to survive and function day-to-day. For instance, they may be overly sensitive to the moods of others, always watching to figure out what the adults around them are feeling and how they will behave. They may withhold their own emotions from others, never letting them see when they are afraid, sad, or angry. These kinds of learned adaptations make sense when physical and/or emotional threats are ever-present. As a child grows up and encounters situations and relationships that are safe, these adaptations are no longer helpful, and may in fact be counterproductive and interfere with the capacity to live, love, and be loved.
Click here to learn more about the effects of complex trauma. Click here  to learn more about the assessment of complex trauma, including guidelines and tools for mental health professionals, as well as additional resources for non-mental health professionals and parents / caregivers.
Complex Trauma Speaker Series  
Since 2008, experts from the NCTSN have presented the Complex Trauma Speaker Series. All presentations are available through the NCTSN Learning Center for Child and Adolescent Trauma . Access to all presentations in the NCTSN Learning Center for Child and Adolescent Trauma is free, and continuing education credits are available.
Polyvictimization and Complex Trauma: Understanding Special Populations, Enhancing Multidisciplinary Responses to Polyvictimization  
This webinar series, a collaborative effort between the OVC National Action Partnership on Polyvictimization and the NCTSN Complex Trauma Workgroup and Complex Trauma Treatment Network, focuses on complex trauma and polyvictimization as they affect a wide range of populations and offers useful tools to a broad range of professionals, including educators, mental health workers, law enforcement, judicial personnel, and child welfare workers.
Complex Trauma in Children and Adolescents (2003) (PDF) 
A white paper from the NCTSN Complex Trauma Task Force
Complex Trauma in Children and Adolescents  (2007) (PDF)
This article appeared in the winter 2007 issue of the journal Focal Point. It is an adaptation and update of the Network white paper listed above. Click here  to access the article. Focal Point is a publication of the Research and Training Center on Family Support and Children's Mental Health.
Complex Trauma in the NCTSN  (PDF)
Results of an NCTSN survey on complex trauma exposure, outcomes, and treatment approaches for impacted children and their families who received intervention and/or comprehensive assessment services in 2002.