Major depression is one of the most prevalent mental health problems in adolescents
and is associated with increased risk for subsequent attempted or completed suicide,
1
comprising more than half of the reported adolescent suicide victims at death.
2
Nevertheless, adolescent depression is more frequently missed than that in adults,
possibly due to the prominence of irritability, mood reactivity, and fluctuating symptoms.
3
For the early detection of depression, screening scales are clinically important;
therefore, the optimal cut‐off score to detect major depressive disorder in various
populations has been investigated.
4
However, distributional patterns of item responses in the adolescent general population
are limited. In order to detect adolescent depression, which is often overlooked,
the distributional pattern of depression symptoms in the general population should
be deeply understood. The Patient Health Questionnaire for Adolescents (PHQ‐A) is
a self‐reporting questionnaire adapted from the adult version of the PHQ‐9, one of
the most used screening tools for major depression worldwide.
4
The PHQ‐A is used to screen for depression among adolescents in a developmentally
appropriate fashion in accordance with the DSM‐IV‐TR criteria.
5
As nine components of the PHQ‐A match the ‘A’ diagnostic criteria for major depression
in the DSM‐5,
6
the distributional pattern of PHQ‐A item responses in the adolescent general population
should be examined to deepen our understanding of various expressions of depression
symptoms among adolescents. Therefore, this study provided distributional patterns
of item responses and total scores using the PHQ‐A among adolescents.
Every year, a community‐based school survey has been prospectively conducted to measure
several mental health indicators and their associated factors among adolescents in
Hirosaki (please see Appendix S1 for more information about Hirosaki City).
7
Data were obtained in September 2019 targeting children between the 4th and 9th grades
in public elementary and junior high schools. We distributed 8003 sets of the PHQ‐A
to the corresponding schools. Classroom teachers explained the contents of this survey
and discussed the concept of informed consent with them. Additionally, we mailed letters
and information on the study to each child's primary caregiver(s), and we excluded
the children whose primary caregivers indicated an intention of not wanting their
children to participate; the cohort included a total of 7765 children (3850 boys [49.6%]
and 3915 girls [50.4%]). Ethical approval was obtained from the Hirosaki University
Committee on Medical Ethics (IRB#2019‐1026). This study was conducted in accordance
with the ethical standards laid down in the 1964 Declaration of Helsinki and its later
amendments.
Before examining the distributional pattern of PHQ‐A item responses, the psychometric
properties of the PHQ‐A for Japanese adolescents were confirmed, which have not been
reported to date (please see Appendix S2).
Table 1 displays the PHQ‐A item responses. Item responses for all nine items showed
a similar pattern. Such a distributional pattern was also reported in a PHQ‐9 study
in adults.
8
The distribution of No. 9 (suicidal ideation) showed a difference between current
and previous studies conducted on adult participants
8
: 83.5% and 96.6% for not at all, 10.7% and 15.0% for several days, 3.1% and 0.6%
for more than half the days, and 2.4% and 0.6% for nearly every day, respectively.
This difference was statistically significant (χ2 = 530.1, d.f. = 3, P < 0.001), suggesting
that adolescents may be more frequently prone to suicidal ideation and suicide attempts
than adults. This result is considered to reflect the current situation in Japan where
the suicide rate for adults is decreasing; however, those for children and adolescents
remain high.
9
Table 1
Distributional patterns of the Patient Health Questionnaire for Adolescents item responses
(n = 7765)
Not at all
Several days
More than half the days
Nearly every day
Missing
Statement
n
%
n
%
n
%
n
%
n
%
Feeling down, depressed, irritable, or hopeless?
4909
63.2
2189
28.2
400
5.2
251
3.2
16
0.2
Little interest or pleasure in doing things?
5552
71.5
1613
20.8
348
4.5
210
2.7
42
0.5
Trouble falling asleep, staying asleep, or sleeping too much?
4179
53.8
1976
25.4
758
9.8
824
10.6
28
0.4
Poor appetite, weight loss, or overeating?
5226
67.3
1564
20.1
557
7.2
384
4.9
34
0.4
Feeling tired or having little energy?
3702
47.7
2476
31.9
891
11.5
679
8.7
17
0.2
Feeling bad about yourself, or feeling that you are a failure, or that you have let
yourself or your family down?
4954
63.8
1625
20.9
592
7.6
573
7.4
21
0.3
Trouble concentrating on things like schoolwork, reading, or watching TV?
5631
72.5
1364
17.6
426
5.5
315
4.1
29
0.4
Moving or speaking so slowly that other people could have noticed?
Or the opposite – being so fidgety or restless that you were moving around a lot more
than usual?
6295
81.1
1035
13.3
254
3.3
160
2.1
21
0.3
Thoughts that you would be better off dead, or of hurting yourself in some way?
6481
83.5
832
10.7
243
3.1
188
2.4
21
0.3
Average
5214
67.2
1630
21.0
496.6
6.4
398.2
5.1
25.44
0.3
Regarding the PHQ‐A total scores, 21.6% of participants had a score of 0, whereas
63.4% of them had a score of 0–4; the percentage of participants who scored 10, which
is the cut‐off score of the PHQ‐9,
4
was 11.1% (please see Appendices [Link], [Link]). These severity distributions are
overall consistent with findings reported in the National Comorbidity Survey – Adolescent
Supplement, which reported the prevalence of depression in adolescents and revealed
that approximately 11% of adolescents have a depressive disorder by age 18 years.
10
This study presents distributional patterns of PHQ‐A item responses and total scores
in the Japanese adolescent general population, which have not been reported previously.
Although study limitations cannot be ignored (e.g., a single‐area study; no data are
available for students who were absent from school during the survey period; the discriminant
validity, including the cut‐off score of the PHQ‐A, has not been examined), this study
has several strengths. Targeting all children in public elementary and junior high
schools in one area with a high participation rate (97.0%) yields highly relevant
community‐based data. These data are the baseline for the long‐term trajectory of
depressive symptoms in our ongoing prospective cohort study. In future studies, the
heterogeneity of the developmental trajectory should be determined among these nine
symptoms, that is, the DSM‐5 ‘A’ diagnostic criteria for major depression.
Disclosure statement
The authors declare that they have no competing interests.
Supporting information
Appendix S1. Information about Hirosaki City.
Click here for additional data file.
Appendix S2. Psychometric properties of the Patient Health Questionnaire for Adolescents
for Japanese adolescents.
Click here for additional data file.
Appendix S3. Distributional patterns of the Patient Health Questionnaire for Adolescents
total scores.
Click here for additional data file.
Appendix S4. The Patient Health Questionnaire for Adolescents total score and severity
classification (N = 7612).
Click here for additional data file.