Early-onset depressive disorders,related mental health disorders and substance use-A prospective : longitudinal study of Finnish twins born 1983-1987

Early-onset psychiatric illnesses effects scatter to academic achievements as well as functioning in familial and social environments. From a public health point of view, depressive disorders are the most significant mental health disorders that begin in adolescence. Using prospective and longitudinal design, this study aimed to increase the understanding of early-onset depressive disorders, related mental health disorders and developing substance use in a large population-derived sample of adolescent Finnish twins. The participants of this study, FinnTwin12, an ongoing longitudinal population-based study, came from Finnish families with twins born in 1983-87 (exhaustive of five birth cohorts, identified from Finland s Central Population Register). With follow-up ongoing at age 20-24, this thesis assessed adolescent mental health in the first three waves, starting from baseline age 11-12 to follow-ups at age 14 and 17½. Some 5600 twins participated in questionnaire assessments of a wide range of health related behaviors. Mental health was further assessed among an intensively studied subsample of 1852 adolescents, who completed also professionally administered interviews at age 14, which provided data for full DSM-IV/III-R (Diagnostic and Statistical Manual for Mental Health disorders, 4th and 3rd editions) diagnoses. The participation rates of the study were 87-92%. The results of the study suggest, that the diagnostic criteria for major depressive disorder (MDD) may not capture youth with clinically significant early-onset depressive conditions outside clinical settings. Milder cases of depression, namely adolescents fulfilling the diagnostic criteria for minor depressive disorder, a qualitatively similar condition to MDD with fewer symptoms are also associated with marked suicidal thoughts, plans and attempts, recurrences and a high degree of comorbidity. Prospectively and longitudinally, early-onset depressive disorders were of substantial importance in the context of other mental health disorders and substance use behaviors: These data from a large population-derived sample established a substantial overlap between early-onset depressive disorders and attention deficit hyperactivity disorder in adolescent females, both of them significantly predictive for development of substance use among girls. Only in females baseline DSM-IV ADHD symptoms were strong predictors of alcohol abuse and dependence and illicit drug use at age 14 and frequent alcohol use and illicit drug use at age 17.½ when conduct disorder and previous substance use were controlled for. Early-onset depressive disorders were also prospectively and longitudinally associated to daily smoking behavior, smokeless tobacco use, frequent alcohol use and illicit drug use and eating disorders. Analysis of discordant twins suggested that these predictive associations were independent of familial confounds, such as family income, structure and parental models. In sum, early-onset depressive disorders predict subsequent involvement of substance use and psychiatric morbidity. A heightened risk for substance use is substantial also among those depressed below categorical diagnosis of MDD. Whether early recognition and interventions among these young people hold potential for substance use prevention further in their lives has potential public health significance and calls for more research. Data from this population-derived sample with balanced representation of boys and girls, suggested that boys and girls with ADHD behaviors may differ from each other in their vulnerability to substance use and depressive disorders: the data suggest more adverse substance use outcome for girls that was not attenuated by conduct disorder or previous substance use. Further, the prospective associations of early-onset depressive disorders and future elevated levels of addictive substance use is not explained by familial factors supporting future substance use, which could have important implications for substance use prevention.Tämän pitkittäistutkimuksen tavoitteena oli lisätä tietoa varhaisesta masennuksesta, sen yhteydessä esiintyvistä mielenterveyden häiriöistä ja päihteidenkäytöstä edustavassa suomalaisessa väestöpohjaisessa aineistossa. Tutkimus on osa Suomalaista Kaksosten Kehitys ja Terveys tutkimusta, jossa seurataan kaikkia Suomessa vuosina 1983-87 syntyneitä kaksosia 12, 14, 17½ ja 20-24 v iässä. Tutkimuksen tulokset perustuvat 1,852:n vuosina 1983-1987 syntyneiden 14-vuotiaiden suomalaisen nuorten henkilökohtaiseen haastatteluun ja seurantakyselyihin 12- ja 17½-vuoden iässä. Tutkimuksessa todettiin, että vakavan masennuksen lisäksi myös nuorten haitallisiksi kokemat masennusoireet ennustavat merkittävästi päivittäistä tupakointia, usein toistuvaa alkoholinkäyttöä, säännöllistä humalajuomista sekä nuuskan ja huumeiden käyttöä, kun muut mielenterveydenhäiriöt, käytöshäiriöt ja jo 14-v alkaneet päihdehäiriöt otetaan huomioon. Masennuksen ja päihteidenkäytön yhteys on todettavissa myös riippumatta yhteisistä perheittäisistä tekijöistä, kuten yhteisestä perimästä ja yhteisestä perheympäristöstä eli esimerkiksi perheen toimeentulosta. Tutkimustulokset viittaavat siihen, että ei-perheittäiset tekijät, kuten nuoren persoonallisuus ja kouluympäristöön sekä toverisuhteisiin liittyvät tekijät saattavat olla merkityksellisiä masentuneen nuoren päihteidenkäytön kehittymisessä. Tässä tutkimuksessa masennuksen yhteydessä esiintyi usein jokin muu mielenterveyden häiriö, kuten käytöshäiriö tai ahdistuneisuushäiriö . Tytöillä varhaisnuoruuden masennus ennusti merkitsevästi syömishäiriöitä 17½ vuoden iässä, etenkin, jos masennukseen liittyi ahdistuneisuutta. Tutkimuksessa todettiin ensikertaa suomalaisessa väestöpohjaisessa pitkittäisasetelmassa yhteissairastavuus tyttöjen masennuksen ja aktiivisuuden ja tarkkaavuuden häiriön (ADHD) välillä. Tässä tutkimuksessa ADHD oireet olivat tytöillä selvästi poikien oireita harvinaisempia, mutta ne ennustivat alkoholin haitallista käyttöä, alkoholiriippuvuutta sekä huumausaineiden tulevaa käyttöä selvästi merkittävämmin kuin poikien ADHD-oireet. Jatkossa on tärkeää selvittää, voitaisiinko masennusta ja muita varhain alkavia tai kehityksellisiä mielenterveyden häiriöitä paremmin tunnistamalla ja hoitamalla vaikuttaa päihteidenkäytön kehittymiseen. Myös lievemmät masennustilat, jotka aiheuttavat toiminnallista haittaa mutta eivät täytä vakavan masennuksen oirekriteerejä altistavat mm. päihteidenkäytön merkittävälle lisääntymiselle ja niillä saattaa korkeamman esiintyvyytensä vuoksi olla huomattava kansanterveydellinen merkitys. Tyttöjen ja poikien alttiudessa päihteidenkäytön kehittymiselle saattaa olla eroja, ja tätä tulisi päihteidenkäytön ehkäisyä ajatellen tutkia lisää. Psykiatrisen hoidon ja päihdehoidon yhteistyötä nuorilla tulee kehittää

Early-onset tobacco use and suicide-related behavior - A prospective study from adolescence to young adulthood

Background: Developmental relationships between tobacco use and suicide-related behaviors (SRB) remain unclear. Our objective was to investigate the longitudinal associations of tobacco use in adolescence and SRB in adulthood. Methods: Using a prospective design, we examined whether tobacco use in adolescence is associated with SRB (intentional self-injury, suicide ideation) in young adulthood in a population-based sample of 1330 twins (626 males, 704 females). The baseline and follow-up data were collected by professionally administered semi-structured poly-diagnostic interviews at ages 14 and 22, respectively. Results: After adjusting for multiple potential confounders, those who reported early-onset of regular tobacco use had a significantly increased risk for intentional self-injury, such as cutting or burning, at age 22 (adjusted odds ratio[AOR] 4.57, 95% CI 1.93-10.8) in comparison to those who had not at all initiated tobacco use. Also, daily cigarette smoking at baseline was associated with future intentional self-injury (AOR 4.45, 95% CI 2.04-9.70). Early-onset tobacco use was associated with suicidal ideation in females (AOR 3.69, 95% CI 1.56-8.72) but not in males. Considering any SRB, baseline daily smokers (AOR 2.13, 95% CI 1.12-4.07) and females with early onset of regular tobacco use (AOR 3.97, 95% CI 1.73-9.13) had an increased likelihood. Within-family analyses among twin pairs discordant for exposure and outcome controlling for familial confounds showed similar, albeit statistically non-significant, associations. Conclusion: Early-onset tobacco use in adolescence is longitudinally associated with SRB (intentional self-injury and/or suicide ideation) in young adulthood, particularly among females. Further investigation may reveal whether this association has implications for prevention of SRB in adolescence and young adulthood.Peer reviewe

Body mass index and subjective well-being in young adults: a twin population study

Peer reviewe

On the Asperger experience of interaction : Interpersonal dynamics in dyadic conversations

We compared the patterns of affiliative and dominant behavior displayed in male dyads where one participant has Asperger's syndrome (AS) with those displayed in male dyads with two neurotypical (NT) participants. Drawing on interpersonal theory, according to which affiliation and dominance constitute two orthogonal axes of the "interpersonal circle," we used a computer-joystick apparatus to assess the participants' moment-to-moment affiliative and dominant behaviors throughout conversation. The patterns of affiliation and dominance were subsequently studied in relation to post-conversation questionnaires that targeted the interactional experiences of the participants in the two different types of dyads (AS dyads, NT dyads). We found the overall interpersonal notion of complementarity to hold for AS and NT dyads alike: greater affiliation in one participant invoked greater affiliation in the co-participant, and greater dominance invoked greater submissiveness in the co-participant. The AS and NT dyads, however, differed with regard to how affiliative and dominant behaviors related to each other during the time course of a single conversation. Furthermore, we found important differences between the AS and NT dyads in how the different patterns of affiliation and dominance were experienced by the participants. For example, a high level of affiliation synchrony was experienced in more negative terms by the participants in the AS dyads than by those in the NT dyads, while a high level of dominance coordination was experienced in more positive terms by the participants in the AS dyads than by those in the NT dyads. The paper increases understanding of the details of the interactional deficits associated with AS and of the conditions in which AS participants may get maximally positive interactional experiences. More generally, our study highlights the necessity to take the study of individual differences in the experiences of patterns of affiliation and dominance into the official agenda of empirical interaction research.Peer reviewe

Physiological responses to affiliation during conversation : Comparing neurotypical males and males with Asperger syndrome

We examined the emotional and psychophysiological underpinnings of social interaction in the context of autism spectrum disorder, more specifically, involving participants diagnosed with Asperger syndrome (AS). We recorded participants’ autonomic nervous system (ANS) activation (electrodermal activity, heart rate, and heart rate variability) and facial muscle activation during conversations in two different types of male dyads: (1) ten dyads where one participant has been diagnosed with AS (AS/NT dyads) and (2) nine dyads where both participants are neurotypical (NT/NT dyads). Afterwards, three independent raters assessed continuously each participant’s affiliative and dominant behaviors during the first and last 10 minutes of the conversations. The relationship between the assessed data and ANS responses was examined. We found that, in the NT/NT dyads, a high level of affiliation displayed by the conversational partner calms down the participant when they are actively dominating the interaction. In contrast, when the participants themselves expressed affiliation, their psychophysiological responses indicated increase in arousal, which suggests that the giving of affiliation is physiologically “hard work.” The affiliation-related ANS responses were similar in those NT participants whose conversational partner had AS, while some differences in facial muscle activation did occur in comparison to NT/NT dyads. In the AS participants, in contrast, a high level of affiliation provided by the conversational partner was associated with increase in arousal, suggesting heightened alertness and stress. As for their own affiliative behavior, the AS participants exhibited similar indicators of alertness and stress as the NT participants, but only when their own level of dominance was low. Our results increase understanding of how individuals with AS experience social interaction at the physiological level, and how this experience differs from that in NT individuals. Moreover, our results confirm and further specify our earlier results, where we proposed that affiliation involves the type of “sharing of the burden” that also reverberates in the participants’ bodies.We examined the emotional and psychophysiological underpinnings of social interaction in the context of autism spectrum disorder, more specifically, involving participants diagnosed with Asperger syndrome (AS). We recorded participants’ autonomic nervous system (ANS) activation (electrodermal activity, heart rate, and heart rate variability) and facial muscle activation during conversations in two different types of male dyads: (1) ten dyads where one participant has been diagnosed with AS (AS/NT dyads) and (2) nine dyads where both participants are neurotypical (NT/NT dyads). Afterwards, three independent raters assessed continuously each participant’s affiliative and dominant behaviors during the first and last 10 minutes of the conversations. The relationship between the assessed data and ANS responses was examined. We found that, in the NT/NT dyads, a high level of affiliation displayed by the conversational partner calms down the participant when they are actively dominating the interaction. In contrast, when the participants themselves expressed affiliation, their psychophysiological responses indicated increase in arousal, which suggests that the giving of affiliation is physiologically “hard work.” The affiliation-related ANS responses were similar in those NT participants whose conversational partner had AS, while some differences in facial muscle activation did occur in comparison to NT/NT dyads. In the AS participants, in contrast, a high level of affiliation provided by the conversational partner was associated with increase in arousal, suggesting heightened alertness and stress. As for their own affiliative behavior, the AS participants exhibited similar indicators of alertness and stress as the NT participants, but only when their own level of dominance was low. Our results increase understanding of how individuals with AS experience social interaction at the physiological level, and how this experience differs from that in NT individuals. Moreover, our results confirm and further specify our earlier results, where we proposed that affiliation involves the type of “sharing of the burden” that also reverberates in the participants’ bodies.Peer reviewe

Determination of Omega_b From Big Bang Nucleosynthesis in the Presence of Regions of Antimatter

Production of regions of antimatter in the early universe is predicted in many baryogenesis models. Small scale antimatter regions would annihilate during or soon after nucleosynthesis, affecting the abundances of the light elements. In this paper we study how the acceptable range in Omega_b changes in the presence of antimatter regions, as compared to the standard big bang nucleosynthesis. It turns out that it is possible to produce at the same time both a low 4He value (Y_p < 0.240) and a low D/H value (D/H < 4e-5), but overproduction of 7Li is unavoidable at large Omega_b.Comment: 9 pages, PRD version, ref. 6 correcte

Constraining Antimatter Domains in the Early Universe with Big Bang Nucleosynthesis

We consider the effect of a small-scale matter-antimatter domain structure on big bang nucleosynthesis and place upper limits on the amount of antimatter in the early universe. For small domains, which annihilate before nucleosynthesis, this limit comes from underproduction of He-4. For larger domains, the limit comes from He-3 overproduction. Most of the He-3 from antiproton-helium annihilation is annihilated also. The main source of He-3 is photodisintegration of He-4 by the electromagnetic cascades initiated by the annihilation.Comment: 4 pages, 2 figures, revtex, (slightly shortened

Human mitochondrial DNA lineages in Iron-Age Fennoscandia suggest incipient admixture and eastern introduction of farming-related maternal ancestry

Human ancient DNA studies have revealed high mobility in Europe's past, and have helped to decode the human history on the Eurasian continent. Northeastern Europe, especially north of the Baltic Sea, however, remains less well understood largely due to the lack of preserved human remains. Finland, with a divergent population history from most of Europe, offers a unique perspective to hunter-gatherer way of life, but thus far genetic information on prehistoric human groups in Finland is nearly absent. Here we report 103 complete ancient mitochondrial genomes from human remains dated to AD 300-1800, and explore mtDNA diversity associated with hunter-gatherers and Neolithic farmers. The results indicate largely unadmixed mtDNA pools of differing ancestries from Iron-Age on, suggesting a rather late genetic shift from hunter-gatherers towards farmers in North-East Europe. Furthermore, the data suggest eastern introduction of farmer-related haplogroups into Finland, contradicting contemporary genetic patterns in Finns.Peer reviewe

Serotonin transporter binding of [123I]ADAM in bulimic women, their healthy twin sisters, and healthy women: a SPET study

<p>Abstract</p> <p>Background</p> <p>Bulimia Nervosa (BN) is believed to be caused by an interaction of genetic and environmental factors. Previous studies support the existence of a bulimia-related endophenotype as well as disturbances in serotonin (5-HT) transmission. We studied serotonin transporter (SERT) binding in BN, and to investigate the possibility of a SERT-related endophenotype for BN, did this in a sample of female twins. We hypothesized clearly reduced SERT binding in BN women as opposed to healthy women, and intermediate SERT binding in unaffected co-twins.</p> <p>Methods</p> <p>We studied 13 female twins with BN (9 with purging and 4 with non-purging BN) and 25 healthy women, including 6 healthy twin sisters of BN patients and 19 women from 10 healthy twin pairs. [¹²³I]ADAM, a selective SERT radioligand for single photon emission tomography (SPET) imaging, was used to assess SERT availability in the midbrain and the thalamus.</p> <p>Results</p> <p>No differences in SERT binding were evident when comparing the BN women, their unaffected co-twins and the healthy controls (p = 0.14). The healthy sisters of the BN patients and the healthy control women had similar SERT binding in both brain regions. In a <it>post hoc </it>subgroup analysis, the purging bulimics had higher SERT binding than the healthy women in the midbrain (p = 0.03), but not in the thalamus.</p> <p>Conclusion</p> <p>Our finding of increased SERT binding in the midbrain in the purging BN women raises the possibility that this subgroup of bulimics might differ in serotonergic function from the non-purging ones. The similarity of the unaffected co-twins and the healthy controls doesn't support our initial assumption of a SERT-related endophenotype for BN. Due to the small sample size, our results need to be interpreted with caution and verified in a larger sample.</p

Inhomogeneous Big Bang Nucleosynthesis and the High Baryon Density Suggested by Boomerang and MAXIMA

The recent Boomerang and MAXIMA data on the cosmic microwave background suggest a large value for the baryonic matter density of the universe, omega_b = 0.03. This density is larger than allowed by standard big bang nucleosynthesis theory and observations on the abundances of the light elements. We explore here the possibility of accommodating this high density in inhomogeneous big bang nucleosynthesis (IBBN). It turns out that in IBBN the observed D and Y_p values are quite consistent with this high density. However, IBBN is not able to reduce the 7Li yield by more than about a factor of two. For IBBN to be the solution, one has to accept that the 7Li plateau in population II halo stars is depleted from the primordial abundance by at least a factor of two.Comment: 6 pages, 4 figures, submitted to PR