The current method of diagnosing depression relies on the patient’s ability to recount their symptoms and the doctor’s ability and training to interpret them.
Diagnosing teenage depression via their symptoms can be tricky because of normal mood changes during those years
Researchers say diagnosing teenagers is an urgent concern because they are highly vulnerable to depression and difficult to accurately diagnose due to normal mood changes at that age.
The new test is also the first to identify subtypes of depression. It distinguished between teens with major depression and those with major depression combined with anxiety disorder. It is the first evidence that it’s possible to diagnose subtypes of depression from blood, raising the hope for tailoring care to the different types.
Lead investigator Eva Redei, a professor of psychiatry and behavioural sciences at Northwestern University Feinberg School of Medicine in the United States, said: 'Right now depression is treated with a blunt instrument.
'It’s like treating type 1 diabetes and type 2 diabetes exactly the same way. We need to do better for these kids.'
She added: 'This is the first significant step for us to understand which treatment will be most effective for an individual patient.
'Without an objective diagnosis, it’s very difficult to make that assessment. The early diagnosis and specific classification of early major depression could lead to a larger repertoire of more effective treatments and enhanced individualized care.'
Mothers suffering from symptoms of depression might disturb their babies’ sleep, according to a new study.
The research found mothers with higher levels of symptoms of depression and more worries about their children’s sleep had children whose sleep was more disrupted.
However, researchers tried to establish if the symptoms of depression led mothers to behave in ways that interfered with their babies’ sleep, or whether the babies’ night wakings lead their moms to be more depressed, perhaps because of sleep loss.
The study found it’s most likely the mums and their behaviour that are responsible. Mums with more symptoms of depression and worries behaved in ways that disrupted their infants’ sleep. For example, picking up babies who were sleeping.
The researchers suggest that mothers who worry excessively about their babies’ well-being at night may respond to infant sounds that don’t necessarily require response or move their babies into their own beds to alleviate their own anxieties about whether their infants are hungry, thirsty, and comfortable.
Mothers who are feeling depressed also may seek out their infants at night for their own emotional comfort.
Study lead author Douglas Teti from Pennsylvania State University, said: 'This study provides insights about maternal depression’s effects on night-time parenting, and how such parenting affects infant sleep.'
He added: “Sleep problems often endure beyond early childhood and can have a negative effect on various aspects of development, including emotional, behavioural, and academic functioning.
'Understanding how maternal depression and sleep problems combine to affect children’s development is important to developing interventions to help reduce these negative consequences.'
The findings were published in the journal Child Development.
The estimated rates of major depressive disorder jump from two to four per cent in pre-adolescent children to 10 to 20 per cent by late adolescence.
Early onset of major depression in teens has a poorer prognosis than when it starts in adulthood. Untreated teens with the disease experience increases in substance abuse, social maladjustment, physical illness and suicide. Their normal development is derailed, and the disease persists into adulthood.
The depressed teens in the study were patients of Doctor Kathleen Pajer, a co-first author of the study, and her colleagues from the Research Institute of Nationwide Children’s Hospital in Columbus, Ohio.
The study subjects included 14 teenagers with major depression who had not been clinically treated and 14 non-depressed teenagers, all aged between 15 and 19. The depressed and control subjects were matched by sex and race.
Prof Redei’s lab tested the adolescents’ blood for 26 genetic blood markers she had identified in previous research. She discovered 11 of the markers were able to differentiate between depressed and non-depressed adolescents.
In addition, 18 of the 26 markers distinguished between patients that had only major depression and those who had major depression combined with anxiety disorder.
Prof Redei said: 'These 11 genes are probably the tip of the iceberg because depression is a complex illness.
'But it’s an entree into a much bigger phenomenon that has to be explored. It clearly indicates we can diagnose from blood and create a blood diagnosis test for depression.'
Prof Redei first isolated and identified the genetic blood markers for depression and anxiety based on decades of research with severely depressed and anxious rats. She said the rats mirror many behavioral and physiological abnormalities found in patients with major depression and anxiety.
Further indicating the challenge in working with depressed adolescents, none of the teens who were diagnosed with depression opted for treatment.
Prof Redei added: 'Everybody, including parents, are wary of treatment, and there remains a social stigma around depression, which in the peer-pressured world of teenagers is even more devastating.
'Once you can objectively diagnose depression as you would hypertension or diabetes, the stigma will likely disappear.'
The study was published in the journal Translational Psychiatry.