Psychoanalytic psychotherapy is also known to have a 'sleeper effect' i.e. its benefits can endure and increase with time.
Adults who received psychoanalytic psychotherapy either as children or as adults report ongoing benefits because psychoanaytic psychotherapy extends its focus to interpersonal relationships not just mental health symptoms, as stated by Harvard Medical School (2010):
"...There is now enough research evidence to claim that psychodynamic therapy is an evidence-based treatment with effect sizes similar to or superior to those reported for other psychotherapies…it is encouraging that the benefits of psychodynamic therapy not only endure after therapy ends, but increase with time. This suggests that insights gained during psychodynamic therapy may equip patients with psychological skills that grow stronger with use".
Harvard Medical School, 2010.