Physical changes such as body shapes changing are inevitable during these years of rapid growth. When these dramatic changes young people often go through a time of feeling uncomfortable or self-conscious with their bodies, even feeling there is something seriously wrong with their body or they do not belong in their body. This can lead to eating disorders, gender dysphoria or severe social anxiety. The teenage years are also associated with dramatic hormonal changes, particularly increases in testosterone (in boys) which is associated with assertiveness, impulsiveness, anger, irritability and increased sexual desire, and oestrogen and progesterone (in girls) with is associated with sexual desire and mood changes.
Brain changes occur as a result of ‘upgrades’ to nerve pathways in the brain through a process of “myelination”. The limbic system (the emotional part of the brain) develops in the early teens, and the pre-frontal cortex (also called the “frontal lobe”) develops in the late teens up to the mid-twenties. Because of this lag in frontal lobe development, many young people have difficulties with managing intense emotions, impulsive behaviour and social relationships, and managing high level academic expectations at school.
Social challenges and changes are also prevalent during these years when main emotional connections shift from parents to friends or romantic or sexual partners. Aside from academic school pressure and time management expectations from higher levels of learning, there is the added challenge of fitting in and being accepted amongst others, with the added stress of bullying or social rejection for some.
There are also many aspects of life that become “legal” in this age bracket, including sexual consent, consenting to medical treatment or driving a car. There are a huge number of skills to learn and may be expected of this age group. All of this poses a strain on the developing brain.
Developing identity is major step in young people, how they see themselves in the world. This includes gender identity, sexual orientation, cultural identity, political beliefs, ideals, morals. It's a period of trying to understand and develop one’s sense of self and where this fits in amongst their friends and family and the world.
Family issues can arise when young people do not have the support base necessary during this time of moving out into the world beyond their family. A secure base offers confidence to young people dealing with this this time of change. Without this support (with feelings of conflict, stress, abandonment or rejection from family), young people may be more vulnerable to mental health problems.
Trauma in earlier childhood years can have severe and lasting effects on how young people feel about themselves. This can include severe bullying at school or being abused or mistreated at home. Many girls experience sexual assault in their teenage years. All these experiences can lead to mental health problems.