Publications 2025

Engen MJ, Lyngstad SH, Eikenæs E, Vøllestad J, Høegh MC, Lagerberg TV, Aminoff SR (2025)
A mixed methods pilot feasibility study of the unified protocol group psychotherapy for early bipolar disorder
Front Psychiatry, 16, 1524243
DOI 10.3389/fpsyt.2025.1524243, PubMed 40496824

Glastad SH, Klungsøyr O, Aminoff SR, Hagen R, Bjella T, Engen MJ, Lyngstad SH, Busch C, Icick R, Etain B, Melle I, Andreassen OA, Høegh MC, Lagerberg TV (2025)
Exploring the temporal relationship between mood, alcohol- and nicotine use in bipolar disorder using time-series analyses
Int J Bipolar Disord, 13 (1), 18
DOI 10.1186/s40345-025-00388-5, PubMed 40407853

Høegh MC, Glastad SH, Lyngstad SH, Engen MJ, Aminoff SR, Melle I, Bjella T, Lagerberg TV (2025)
The MinDag app for symptom monitoring and feedback to patients and clinicians during the initial treatment of bipolar disorder - a feasibility study
Int J Bipolar Disord, 13 (1), 14
DOI 10.1186/s40345-025-00382-x, PubMed 40178653

Kreis I, Fjelnseth Wold K, Åsbø G, Bärthel Flaaten C, Engen MJ, Lyngstad SH, Hustad Widing L, Sheikh MA, Frogner Werner MC, Bakken E, Ueland T, Steen NE, Melle I (2025)
Recent cannabis use affects the association between baseline immune markers and long-term outcomes in psychosis
Transl Psychiatry, 15 (1), 282
DOI 10.1038/s41398-025-03498-x, PubMed 40813774

Publications 2024

Kreis I, Lagerberg TV, Wold KF, Åsbø G, Simonsen C, Flaaten CB, Engen MJ, Lyngstad SH, Widing LH, Ueland T, Melle I (2024)
Behind the heterogeneity in the long-term course of first-episode psychosis: Different psychotic symptom trajectories are associated with different patterns of cannabis and stimulant use
Schizophr Res, 271, 91-99
DOI 10.1016/j.schres.2024.07.006, PubMed 39018985

Kreis I, Wold KF, Åsbø G, Simonsen C, Flaaten CB, Engen MJ, Lyngstad SH, Widing LH, Ueland T, Melle I (2024)
The relationship between visual hallucinations, functioning, and suicidality over the course of illness: a 10-year follow-up study in first-episode psychosis
Schizophrenia (Heidelb), 10 (1), 30
DOI 10.1038/s41537-024-00450-8, PubMed 38431677

Simonsen C, Åsbø G, Slade M, Wold KF, Widing L, Flaaten CB, Engen MJ, Lyngstad SH, Gardsjord E, Bjella T, Romm KL, Ueland T, Melle I (2024)
A good life with psychosis: rate of positive outcomes in first-episode psychosis at 10-year follow-up
Psychol Med, 54 (9), 2112-2121
DOI 10.1017/S0033291724000205, PubMed 38389456

Wold KF, Kreis IV, Åsbø G, Flaaten CB, Widing L, Engen MJ, Lyngstad SH, Johnsen E, Ueland T, Simonsen C, Melle I (2024)
Long-term clinical recovery and treatment resistance in first-episode psychosis: a 10-year follow-up study
Schizophrenia (Heidelb), 10 (1), 69
DOI 10.1038/s41537-024-00489-7, PubMed 39174576

Publications 2023

Flaaten CB, Melle I, Bjella T, Engen MJ, Åsbø G, Wold KF, Widing L, Gardsjord E, Øie MG, Lyngstad SH, Haatveit B, Simonsen C, Ueland T (2023)
Long-term course of cognitive functioning in bipolar disorder: A ten-year follow-up study
Bipolar Disord, 26 (2), 136-147
DOI 10.1111/bdi.13364, PubMed 37356974

Ihler HM, Lyngstad SH, Gardsjord ES, Widing LH, Flaaten CB, Åsbø G, Wold KF, Engen MJ, Simonsen C, Ueland T, Lagerberg TV, Melle I, Romm KL (2023)
The trajectory of two negative symptom dimensions in first-episode psychosis and the role of cannabis use: A 10-year follow-up study
Schizophr Res, 252, 317-325
DOI 10.1016/j.schres.2023.01.024, PubMed 36706477

Ihler HM, Lyngstad SH, Mørch-Johnsen LE, Lagerberg TV, Melle I, Romm KL (2023)
A transdiagnostic approach to negative symptoms: exploring factor structure and negative symptoms in bipolar disorders
Front Psychiatry, 14, 1136097
DOI 10.3389/fpsyt.2023.1136097, PubMed 37398600

Lyngstad SH, Lyne JP, Ihler HM, van der Meer L, Færden A, Melle I (2023)
Turning the Spotlight on Apathy: Identification and Treatment in Schizophrenia Spectrum Disorders
Schizophr Bull, 49 (5), 1099-1104
DOI 10.1093/schbul/sbad070, PubMed 37193675

Widing L, Simonsen C, Bjella T, Engen MJ, Flaaten CB, Gardsjord E, Haatveit B, Haug E, Lyngstad SH, Svendsen IH, Vik RK, Wold KF, Åsbø G, Ueland T, Melle I (2023)
Long-term Outcomes of People With DSM Psychotic Disorder NOS
Schizophr Bull Open, 4 (1), sgad005
DOI 10.1093/schizbullopen/sgad005, PubMed 39145337

Publications 2022

Engen MJ, Vaskinn A, Melle I, Færden A, Lyngstad SH, Flaaten CB, Widing LH, Wold KF, Åsbø G, Haatveit B, Simonsen C, Ueland T (2022)
Cognitive and Global Functioning in Patients With First-Episode Psychosis Stratified by Level of Negative Symptoms. A 10-Year Follow-Up Study
Front Psychiatry, 13, 841057
DOI 10.3389/fpsyt.2022.841057, PubMed 35401286

Flaaten CB, Melle I, Bjella T, Engen MJ, Åsbø G, Wold KF, Widing L, Gardsjord E, Sæther LS, Øie MG, Lyngstad SH, Haatveit B, Simonsen C, Ueland T (2022)
Domain-specific cognitive course in schizophrenia: Group- and individual-level changes over 10 years
Schizophr Res Cogn, 30, 100263
DOI 10.1016/j.scog.2022.100263, PubMed 35783460

Flaaten CB, Melle I, Gardsjord E, Bjella T, Engen MJ, Vaskinn A, Åsbø G, Wold KF, Widing L, Lyngstad SH, Haatveit B, Simonsen C, Ueland T (2022)
Course of intellectual functioning in schizophrenia and bipolar disorder: a 10-year follow-up study
Psychol Med, 53 (6), 2662-2670
DOI 10.1017/S0033291721004645, PubMed 35256030

Åsbø G, Ueland T, Haatveit B, Bjella T, Flaaten CB, Wold KF, Widing L, Engen MJ, Lyngstad SH, Gardsjord E, Romm KL, Melle I, Simonsen C (2022)
The Time is Ripe for a Consensus Definition of Clinical Recovery in First-episode Psychosis: Suggestions Based on a 10-Year Follow-up Study
Schizophr Bull, 48 (4), 839-849
DOI 10.1093/schbul/sbac035, PubMed 35419608

Publications 2021

Ihler HM, Lagerberg TV, Lyngstad SH, Melle I, Romm KL (2021)
Exploring the relationship between recency and frequency of cannabis use and diminished expression and apathy as two dimensions of negative symptoms in first episode psychosis. A one-year follow-up study
Schizophr Res, 236, 89-96
DOI 10.1016/j.schres.2021.08.004, PubMed 34454305

Publications 2020

Engen MJ, Lyngstad SH, Ueland T, Simonsen CE, Vaskinn A, Smeland O, Bettella F, Lagerberg TV, Djurovic S, Andreassen OA, Melle I (2020)
Polygenic scores for schizophrenia and general cognitive ability: associations with six cognitive domains, premorbid intelligence, and cognitive composite score in individuals with a psychotic disorder and in healthy controls
Transl Psychiatry, 10 (1), 416
DOI 10.1038/s41398-020-01094-9, PubMed 33257657

Haatveit B, Mørch-Johnsen L, Alnæs D, Engen MJ, Lyngstad SH, Færden A, Agartz I, Ueland T, Melle I (2020)
Divergent relationship between brain structure and cognitive functioning in patients with prominent negative symptomatology
Psychiatry Res Neuroimaging, 307, 111233
DOI 10.1016/j.pscychresns.2020.111233, PubMed 33340940

Lyngstad SH, Gardsjord ES, Engen MJ, Haatveit B, Ihler HM, Wedervang-Resell K, Simonsen C, Melle I, Færden A (2020)
Trajectory and early predictors of apathy development in first-episode psychosis and healthy controls: a 10-year follow-up study
Eur Arch Psychiatry Clin Neurosci, 270 (6), 709-722
DOI 10.1007/s00406-020-01112-3, PubMed 32130475

Publications 2019

Engen MJ, Simonsen C, Melle I, Færden A, Lyngstad SH, Haatveit B, Vaskinn A, Ueland T (2019)
Cognitive functioning in patients with first-episode psychosis stratified by level of negative symptoms: A 1-year follow-up study
Psychiatry Res, 281, 112554
DOI 10.1016/j.psychres.2019.112554, PubMed 31499342

Wedervang-Resell K, Friis S, Lonning V, Smelror RE, Johannessen C, Reponen EJ, Lyngstad SH, Lekva T, Aukrust P, Ueland T, Andreassen OA, Agartz I, Myhre AM (2019)
Increased interleukin 18 activity in adolescents with early-onset psychosis is associated with cortisol and depressive symptoms
Psychoneuroendocrinology, 112, 104513
DOI 10.1016/j.psyneuen.2019.104513, PubMed 31761332

Publications 2018

Faerden A, Lyngstad SH, Simonsen C, Ringen PA, Papsuev O, Dieset I, Andreassen OA, Agartz I, Marder SR, Melle I (2018)
Reliability and validity of the self-report version of the apathy evaluation scale in first-episode Psychosis: Concordance with the clinical version at baseline and 12 months follow-up
Psychiatry Res, 267, 140-147
DOI 10.1016/j.psychres.2018.05.065, PubMed 29906681

Lyngstad SH, Gardsjord ES, Simonsen C, Engen MJ, Romm KL, Melle I, Færden A (2018)
Consequences of persistent depression and apathy in first-episode psychosis - A one-year follow-up study
Compr Psychiatry, 86, 60-66
DOI 10.1016/j.comppsych.2018.07.015, PubMed 30081208

Publications 2017

Gjerde PB, Dieset I, Simonsen C, Hoseth EZ, Iversen T, Lagerberg TV, Lyngstad SH, Mørch RH, Skrede S, Andreassen OA, Melle I, Steen VM (2017)
Increase in serum HDL level is associated with less negative symptoms after one year of antipsychotic treatment in first-episode psychosis
Schizophr Res, 197, 253-260
DOI 10.1016/j.schres.2017.10.042, PubMed 29129510