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Phenomenology and Comorbidity of Dysthymic Disorder in 100 Consecutively Referred Children and Adolescents: Beyond DSM-IV
Results
Regarding the number of depressive symptoms, no statistically significant differences (t-test) were observed between children (mean 6.83, SD 1.68) and adolescents (mean 7.51, SD 1.99) and between female patients (mean 7.35 SD 2.00) and male patients (mean 7.07, SD 2.07). ANOVAs did not reveal significant age by sex interaction. The distribution was acceptably normal (skewness = –0.067; kurtosis = –0.63).
Prevalence of depressive symptoms in the whole sample of 100 children and adolescents with DD is presented in Table 1. Data show that irritability was the most frequently reported symptom, followed by low self-concept, fatigue and loss of energy, depressed mood, guilt, concentration difficulties, anhedonia, and hopelessness. Psychomotor agitation was present in about one-half of the patients, and retardation occurred in less than 20%. The least-frequent symptoms were hypersomnia (10%; contrasted with insomnia, which was reported by 45% of patients) and increased appetite (12%; contrasted with reduced appetite reported by 29% of patients). Significantly, 36% of the patients had thoughts of death. No significant differences in symptomatic profile were apparent between male and female patients (Table 1).
Comparisons between children and adolescents indicate that 2 symptoms were more frequently reported in adolescents: thoughts of death (48.4% vs 13.9%) (c2 = 10.5, df 1, P = 0.001) and anhedonia (64% vs 33.3%) (c2 = 7.5, df 1, P = 0.006). Only differences in thoughts of death remained significant after the Bonferroni correction, which set P < 0.003.
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Table 1 Depressive symptomatology in patients with dysthymic disorder
according to age and sex
|
|
Symptoms
|
Whole sample
(n = 100)
n (%)
|
Males
(n = 57)
n (%)
|
Females
(n = 43)
n (%)
|
Children
(n = 36)
n (%)
|
Adolescents
(n = 64)
n (%)
|
|
Irritability
|
86
|
47 (82.4)
|
39 (90.7)
|
31 (86.1)
|
55 (85.9)
|
|
Low self-concept
|
79
|
46 (80.7)
|
33 (76.7)
|
30 (83.3)
|
49 (76.5)
|
|
Fatigue
|
73
|
43 (75.4)
|
30 (69.7)
|
30 (83.3)
|
43 (67.2)
|
|
Depressed mood
|
69
|
37 (64.9)
|
32 (74.4)
|
27 (75.0)
|
42 (65.6)
|
|
Guilt
|
61
|
30 (52.6)
|
31 (72.1)
|
24 (66.7)
|
37 (57.8)
|
|
Concentration difficulties
|
58
|
37 (65.0)
|
21 (48.8)
|
19 (52.7)
|
39 (61.0)
|
|
Anhedonia
|
53
|
31 (54.3)
|
22 (51.2)
|
12 (33.3)
|
41 (64.0)
|
|
Hopelessness
|
52
|
30 (52.6)
|
22 (51.2)
|
16 (44.4)
|
36 (56.2)
|
|
Psychomotor agitation
|
46
|
29 (50.8)
|
17 (39.5)
|
15 (41.7)
|
31 (48.4)
|
|
Insomnia
|
45
|
25 (43.8)
|
20 (46.5)
|
16 (44.4)
|
29 (45.3)
|
|
Death thoughts
|
36
|
19 (33.3)
|
17 (39.5)
|
5 (13.9)
|
31 (48.4)a
|
|
Reduced appetite
|
29
|
18 (31.6)
|
11 (25.6)
|
11 (30.5)
|
18 (28.1)
|
|
Psychomotor retardation
|
17
|
9 (15.8)
|
8 (18.6)
|
6 (16.6)
|
11 (17.2)
|
|
Increased appetite
|
12
|
7 (12.3)
|
5 (11.6)
|
2 (5.5)
|
10 (15.6)
|
|
Hypersomnia
|
10
|
4 (7.0)
|
6 (13.9)
|
2 (5.5)
|
8 (12.5)
|
|
aStatistically significant (Bonferroni correction, P < 0.003).
|
Comparisons among age–sex groups (male children, female children, male adolescents, and female adolescents) (Table 2) showed that anhedonia (c2 = 9.2, df 3, P = 0.034) and thoughts of death (c2 = 17.47, df 3, P < 0.001) distinguished the 4 groups, but only thoughts of death remained significant after the Bonferroni correction.
The comorbidity of DD was analyzed separately in the whole sample as a function of sex and age (Table 3). Anxiety disorders were frequently comorbid with DD: 59% of the patients had GAD, 28% had simple phobias, 18% had separation anxiety disorder, 14% had obsessive–compulsive disorder, 13% had social phobia, and 10% had panic disorder. Comorbid externalizing disorders (that is, attention deficit disorder with hyperactivity, oppositional defiant disorder, and conduct disorder) were reported in 35% of patients. Statistical analyses (Bonferroni correction, P < 0.007) showed that children had more frequent separation anxiety disorder than adolescents (36.1% vs 7.8%) (c2 = 10.6, df 1, P = 0.001). Externalizing disorders were more frequently reported in male than in female patients (47.4% vs 18.6%) (c2 = 7.7, df 1, P = 0.006) .
Table 4 compares comorbidity in age–sex groups (male children, female children, male adolescents, and female adolescents): separation anxiety disorder (c2 = 16.17, df 3, P = 0.001) and externalizing disorders (c2 = 4.79, df 3, P = 0.01) distinguished the 4 groups, but only separation anxiety disorder remained significant after Bonferroni correction (P < 0.007). The group effect of separation anxiety disorder was due to its prevalence in children vs adolescents, as well as to its prevalence in female adolescents vs male adolescents. Externalizing disorders were equally prevalent in male patients, among both children and adolescents.
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Table 2 Depressive symptomatology in patients with dysthymic disorder
according to age–sex groups
|
|
Symptoms
|
Male children
(n = 21)
n (%)
|
Female children
(n = 15)
n (%)
|
Male adolescents
(n = 36)
n (%)
|
Female adolescents
(n = 28)
n (%)
|
|
Irritability
|
17 (80.9 )
|
12 (80.0)
|
22 (61.1)
|
20 (71.4)
|
|
Low self-concept
|
19 (90.5)
|
11 (73.3)
|
27 (75.0)
|
22 (78.6)
|
|
Fatigue
|
17 (80.9)
|
13 (86.6)
|
26 (72.2)
|
17 (60.7)
|
|
Depressed mood
|
15 (71.4)
|
12 (80.0)
|
22 (61.1)
|
20 (71.4)
|
|
Guilt
|
12 (57.1)
|
12 (80.0)
|
18 (50.0)
|
19 (67.8)
|
|
Concentration difficulties
|
10 (47.6)
|
9 (60)
|
27 (75.0)
|
12 (42.8)
|
|
Anhedonia
|
8 (38.1)
|
4 (26.6)
|
23 (63.9)
|
18 (64.3)
|
|
Hopelessness
|
9 (42.8)
|
7 (46.6)
|
21 (58.3)
|
15 (53.6)
|
|
Psychomotor agitation
|
10 (47.6)
|
5 (33.3)
|
19 (52.8)
|
12 (42.8)
|
|
Insomnia
|
10 (47.6)
|
6 (40.0)
|
15 (41.6)
|
14 (50.0)
|
|
Death thoughts
|
5 (23.8)
|
0 (0.0)
|
15 (41.6)
|
17 (60.7)a
|
|
Reduced appetite
|
8 (38.1)
|
3 (20.0)
|
10 (27.8)
|
8 (28.6)
|
|
Psychomotor retardation
|
3 (14.3)
|
3 (20.0)
|
6 (16.6)
|
5 (17.8)
|
|
Increased appetite
|
2 (9.5)
|
0 (0.0)
|
5 (13.9)
|
5 (17.8)
|
|
Hypersomnia
|
4 (7.0)
|
6 (13.9)
|
2 (5.5)
|
8 (12.5)
|
|
aStatistically significant (Bonferroni correction, P < 0.003).
|
|
Table 3 Comorbidity in patients with dysthymic disorder according to age
and sex
|
|
Syndromes
|
Whole sample
(n = 100)
n (%)
|
Males
(n = 57)
n (%)
|
Females
(n = 43)
n (%)
|
Children
(n = 36)
n (%)
|
Adolescents
(n = 64)
n (%)
|
|
Generalized anxiety disorder
|
59
|
35 (61.4)
|
24 (55.8)
|
19 (52.8)
|
40 (62.5)
|
|
Simple phobias
|
28
|
19 (35.1)
|
9 (21)
|
10 (27.7)
|
18 (28.1)
|
|
Separation anxiety disorder
|
18
|
7 (12.3)
|
11 (25.6)
|
13 (36.1)
|
5 (7.8)a
|
|
Social phobia
|
13
|
7 (12.3)
|
6 (14)
|
2 (5.5)
|
11 (17.1)
|
|
Obsessive–compulsive disorder
|
14
|
8 (14)
|
6 (14)
|
3 (8.3)
|
11 (17.2)
|
|
Panic disorder
|
10
|
6 (10.5)
|
4 (9.3)
|
1 (2.7)
|
9 (14)
|
|
Externalizing disorder
|
35
|
27 (47.4)
|
8 (18.6)a
|
13 (36.1)
|
22 (34.4)
|
|
aStatistically significant (Bonferroni correction, P < 0.007).
|
|
Table 4 Comorbidity in patients with dysthmic disorder according to age–sex
groups
|
|
Syndromes
|
Male children
(n = 21)
n (%)
|
Female children
(n = 15)
n (%)
|
Male adolescents
(n = 36)
n (%)
|
Female adolescents
(n = 28)
n (%)
|
|
Generalized anxiety disorder
|
27 (47.3)
|
23 (53.5)
|
15 (41.6)
|
35 (54.6)
|
|
Separation anxiety disorder
|
7 (33.3)
|
6 (40.0)
|
0 (0.0)
|
5 (17.8)a
|
|
Panic disorder
|
0 (0.0)
|
1 (6.6)
|
6 (16.6)
|
3 (10.7)
|
|
Social phobia
|
2 (9.5)
|
0 (0.0)
|
5 (13.9)
|
6 (21.4)
|
|
Simple phobias
|
7 (33.3)
|
3 (20.0)
|
12 (33.3)
|
6 (21.4)
|
|
Obsessive–compulsive disorder
|
1 (4.7)
|
2 (13.3)
|
6 (16.6)
|
2 (7.1)
|
|
Externalizing disorder
|
10 (47.7)
|
3 (20.0)
|
17 (47.2)
|
5 (17.8)
|
|
aStatistically significant (Bonferroni correction, P < 0.007).
|
Discussion
Our findings on the entire sample of patients with DD showed that irritability, fatigue or loss of energy, low self-esteem, depressed mood, guilt, concentration difficulties, anhedonia, and hopelessness are present in more than 50% of subjects. Other studies have underscored that the predominant mood in early-onset depressive disorders is irritability and dysphoria rather than sadness or melancholia (24). Most reported symptoms pertain to emotional or cognitive, rather than somatic and vegetative, domains. Only fatigue is more frequently represented in our sample, compared with the only previous study of the symptomatic expression of juvenile DD. Our data seem to underline the high frequency of some of the symptoms reported in the alternative DSM-IV research diagnostic criteria for DD (especially feelings of irritability, guilt, and anhedonia). Otherwise, these findings suggest that, at least for juvenile DD, DSM-IV diagnostic criteria may be inappropriate. As reported in other studies on clinical samples (6,14), boys and girls were equally represented.
Symptomatic profile is generally similar in children and adolescents; only thoughts of death were significantly more frequent in adolescent males. Affective and cognitive symptoms are commonly reported both in children and in adolescents. Most interesting is the high frequency in young children of low self-image (76.5%), depressed mood (65.6%), and guilty feelings (57.8%), which are often neglected or denied by parents (25,26) and are considered typical of adolescence. An interview with questions that specifically explore these areas has shown that they are much more common in children than previously recognized.
Notably, psychomotor agitation is present in 45% of our patients, which is 3 times more frequently than psychomotor retardation. This finding, as well as the high frequency of other symptoms such as irritability and poor concentration, suggests the presence of “mixed” bipolar elements in a relevant proportion of patients. Hypomanic and mixed features during major depression and dysthymia in children and adolescents have been previously reported by others (27,28). These symptoms, either spontaneous or pharmacologically induced, can represent a significant complication during the course of the depressive illness in a substantial minority of children and adolescents. Further, this observation confirms that, in a significant minority, early-onset DD belongs to the bipolar spectrum.
Anxiety disorders are commonly comorbid with DD, especially GAD and separation anxiety disorder (31). Sex did not appear to affect anxiety comorbidity, except for separation anxiety disorder, which was not reported in male adolescents. Lower rates of anxiety comorbidity (40% to 55%) are reported by Kovacs and others (6) and by Goodman and others (15). Although we have paid specific attention to distinguishing DD from GAD, a particularly high comorbidity between these 2 disorders was seen in our study. In the Goodman and coworkers’ study, based on a community sample, the rate of GAD in pure DD was 9%, even though it climbed to 44% when associated with MDD (15). In Kovacs and coworkers’ study, considering only ambulatory children, 17% of the pure DD and 31% of the DD–MDD patients had a comorbid overanxious disorder (10). The fact that we used patients who had been referred to our research group (both inpatients and outpatients) may have amplified this comorbidity.
Anxious comorbidity has been associated with a risk of bipolarity (32), increased severity of the chronic depression, and a poorer outcome in adult patients (33), but it did not affect recovery rate in children and adolescents with DD (8). Our cross-sectional data do not permit us to draw prognostic implications.
Externalizing disorders are reported in about one-third of our sample and, as expected, are more common in male than in female patients, both among children and adolescents (1). Similar rates of comorbidity, ranging from 31% to 41%, were reported by Kovacs and others (6) in a clinical sample and by Goodman and others (15) in a community sample. Higher rates of behavioural disorders were reported by Ferro and others (14), who found externalizing disorders in all their 18 children with DD, and by Asarnow and Ben-Mair (19). In our previous study (23), in which children were the main source of information, a lower rate of externalizing disorder (14%) was reported, while rates of anxiety comorbidity were similar to the present study. In children’s reports, greater weight is given to subjective experiences, while parents are more prone to report behavioural symptoms (25,26).
A limitation of this study may be that the severity of the symptomatology and the rates of comorbidity are greater in referred samples than in the general, nonreferred population (34). The mean number of symptoms (about 7) and the rate of thoughts of death and anxiety comorbidity, which were higher than in a previous report (6), suggest that our patients may represent a particularly severe sample of DD. On the other hand, this study provides information about DD as observed in practice settings of child and adolescent psychiatry.
DD has an insidious onset during childhood or adolescence (6). Considering the interval between the onset of DD and other superimposed mental disorders (that is, superimposed MDD usually occurs 2 to 3 years after the onset of DD) (6), and the possibility of a bipolar evolution (27,28,30), an early diagnosis is crucial. A timely intervention, indeed, provides the best opportunity for possible prevention of subsequent psychopathological and functional impairment.
It is finally noteworthy that, as in adults (3,35), pure DD is characterized primarily by emotional–cognitive manifestations, which are less prominent in the DSM-IV list. As discussed, these are the very symptoms reported by children and adolescents—not their parents.
References
1. American Psychiatric Association. Diagnostic and Statistical Manual for Mental Disorders 4th ed. Washington (DC): American Psychiatric Association, 1994.
2. Kovacs M, Obrosky DS, Gatsonis C, Richards C. First-episode major depressive and dysthymic disorder in childhood: clinical and sociodemographic factors in recovery. J Am Acad Child Adolesc Psychiatry 1997;36:777–84.
3. Akiskal HS, Rosenthal, TL, Haykal RF, Lemmi H, Rosenthal RH, Scott-Strauss A. Clinical and EEG findings separating “subaffective dysthymias” from “character spectrum disorders”. Arch Gen Psychiatry 1980;37:777–83.
4. Kashani JH, Allan WD, Beck NC, Bledsoe Y, Reid JC. Dysthymic disorder in clinically referred preschool children. J Am Acad Child Adolesc Psychiatry 1997;36:1426–33.
5. Akiskal HS, Weise RE. The clinical spectrum of so-called “minor” depressions. Am J Psychother 1992;66:9–22.
6. Kovacs M, Akiskal S, Gatsonis C, Parrone PL. Childhood-onset dysthymic disorder. Arch Gen Psychiatry 1994;51:365–74.
7. Akiskal HS. Subaffective disorders: dysthymic, cyclothimic and bipolar II disorders in the borderline realm. Psychiatr Clin North Am 1981;4:25–46.
8. Kovacs M, Feinberg TL, Crouse-Novak M, Paulaskas SL, Finkelstein R. Depressive disorders in childhood. II: a longitudinal study of the risk of a subsequent major depression. Arch Gen Psychiatry 1984; 41:643–49.
9. Lewinshon PM, Rohde P, Seeley JR, Hops H. Comorbidity of unipolar depression. I: major depression with dysthymia. J Abnorm Psychol 1991;100:205–13.
10. Kovacs M, Gatsonis C, Paulaskas SL, Richards C. Depressive disorders in childhood. IV: a longitudinal study of comorbidity with and risk for anxiety disorders. Arch. Gen. Psychiatry 1984;46:776–82.
11. Fine S, Moretti M, Haley G, Marriage K. Affective disorders in children and adolescents: the dysthymic disorder dilemma. Can J Psychiatry 1985;30:173–77.
12. Markowitz JC, Moran ME, Kocsis JH, Frances AJ. Prevalence and comorbidity of dysthymic disorder among psychiatric outpatients. J Affect Disord 1992; 24:63–71.
13. Masi G, Mucci M, Favilla L, Romano R, Poli P. Symptomatology and comorbidity of generalized anxiety disorder in children and adolescents. Comprehen Psychiatry 1999; 40:210–15.
14. Ferro T, Carlson GA, Grayson P, Klein DN. Depressive disorders: distinctions in children. J Am Acad Child Adolesc Psychiatry 1994;33:664–70.
15. Goodman SH, Schwab-Stone M, Lahey BB, Shaffer D, Jensen PS. Major depression and dysthymia in children and adolescents: discriminant validity and differential consequences in a community sample. J Am Acad Child Adolesc Psychiatry 2000; 39:761–70.
16. Bernstein GA. Comorbidity and severity of anxiety and depressive disorders in a clinic sample. J Am Acad Child Adolesc Psychiatry 1991;30:43–50.
17. Shores MM, Glub T, Cowley DS, Dager SR, Roy-Bryne PP, Dunner PL. The relationship between anxiety and depression: a clinical comparison of generalized anxiety disorder, dysthymic disorder, panic disorder and major depressive disorder. Comprehen Psychiatry 1992;33:237–44.
18. Ryan ND, Puig Antich J, Ambrosini PJ, Rabinovich H, Robinson D, Nelson B, Iyengar S, Twomey J. The clinical picture of major depression in children and adolescents. Arch Gen Psychiatry 1987;44:854–61.
19. Asarnow JR, Ben-Meir S. Children with schizophrenia spectrum and depressive disorders: a comparative study of premorbid adjustment, onset pattern and severity of impairment. J Child Psychol Psychiat 1988;29:477–88.
20. Shain BN, King CA, Naylor M, Alessi N. Chronic depression and hospital course in adolescents. J Am Acad Child Adolesc Psychiatry 1991;30:428–33.
21. Reich W. Diagnostic interview for children and adolescents—revised DSM-IV version. Toronto (ON): Multi-Health Systems; 1997.
22. Hollingshead AB. Two Factor Index of social position. Unpublished manuscript. New Haven (CT): Yale University, Department of Sociology; 1957.
23. Masi G, Favilla L, Mucci M, Poli P, Romano R. Depressive symptoms in children and adolescents with dysthymic disorder. Psychopathology 2001;34:29–35.
24. Biederman J, Faraone S, Mick E, Lelon E. Psychiatric comorbidity among referred juveniles with major depression: fact or artifact? J Am Acad Child Adolesc Psychiatry 1995;34:579–90.
25. Angold A, Weissman MM, John K. Parent and child reports of depressive symptoms in children at low and high risk of depression. J Child Psychol Psychiat 1987;28:901–15.
26. Walker M, Moreau D, Weissman MM. Parents’ awareness of children’s suicide attempts. Am J Psychiatry 1990;147:1364–6.
27. Geller B, Fox L, Clark K. Rate and predictors of prepubertal bipolarity during follow-up of 6- to 12-year-old depressed children. J Am Acad Child Adolesc Psychiatry 1994;33:461–8.
28. Strober M, Carlson G. Bipolar illness in adolescents with major depression: clinical genetic, and psychopharmacologic predictors in a three- to four-year prospective follow-up investigation. Arch Gen Psychiatry 1982;39:549–55.
29. Rosenthal TL, Akiskal HS, Scott-Strauss A, Rosenthal RH, David M. Familial and developmental factors in characterological depression. J Affect Disord 1981;3:183–92.
30. Akiskal HS. Developmental pathways to bipolarity: are juvenile-onset depressions pre-bipolar? J Am Acad Child Adolesc Psychiatry 1995;34:754–63.
31. Masi G, Mucci M, Favilla L, Millepiedi S. Anxiety comorbidity in referred children and adolescents with dysthymic disorder. Psychopathology 2001;34:253–8.
32. Masi G, Toni C, Perugi G, Mucci M, Millepiedi S, Akiskal HS. Anxiety disorders in consecutively referred children and adolescents with bipolar disorder: a neglected comorbidity. Can J Psychiatry 2001;46:797–802.
33. Sherbourne CD, Wells KB. Course of depression in patients with comorbid anxiety disorders. J Affect Disord 1997;43:245–50.
34. Goodman SH, Lahey BB, Fielding B, Dulcan M, Narrow W, Regier D. Representativeness of clinical samples of youth with mental disorders: a preliminary, population-based study. J Abnorm Psychol 1997;25:121–32.
35. Haykal RF, Akiskal HS. The long-term outcome of dysthymia in private practice: clinical features, temperament, and the art of management. J Clin Psychiatry 1999;60:508–18.
Manuscript received March 2002, revised, and accepted July 2002.
1. Researchers, IRCCS Stella Maris, Division of Child Neurology and Psychiatry, Calambrone, Pisa, Italy.
2. Researcher, Department of Psychiatry, Neurobiology, Pharmacology and Biotechnologies, Psychiatry Section, University of Pisa, Institute of Behavior Sciences G De Lisio, Carrara-Pisa, Italy.
3. Professor and Director, International Mood Center, Department of Psychiatry at the University of California at San Diego, La Jolla, California.
Address for correspondence: Dr G Masi, MD, IRCCS Stella Maris, Via dei Giacinti 2, 56018 Calambrone Pisa, Italy.
e-mail: gabriele.masi@inpe.unipi.it.
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