Methods for treating depressive symptoms

A method of treating a depressive symptom in a subject comprising administering to the subject a compound of Formula IV:

• or a pharmaceutically acceptable salt thereof, wherein
• R1 is C1-C6 alkyl, C2-C6 alkenyl, aryl, cycloalkyl, heterocyclyl, benzyl, hydroxyalkyl, or alkoxyalkyl;
• R1a is H or methyl;
• R2 is H, hydroxyl, or methoxy;
• and
• R3 and R4 are each methyl, or alternatively, R3 and R4, together with the carbon atoms to which they are attached, form a 6-membered unsubstituted carbocyclic ring;
• wherein the depressive symptom is selected from the group consisting of depressed mood, loss of pleasure, loss of appetite, sleep disturbance, psychomotor changes, fatigue, post-partum depression, a depressive symptom associated with a mental condition, acute stress disorder, an adjustment disorder with depressed mood, Asperger syndrome, attention deficit, bereavement, bipolar I disorder, bipolar II disorder, borderline and personality disorder, cyclothymia, dysthymia, depression, Dysthymic disorder, hyperactivity disorder, impulse control disorder, mixed mania, obsessive-compulsive personality disorder (OCD), paranoid, post-traumatic stress disorder, seasonal affective disorder, self-injury separation, sleep disorder, substance-induced mood disorder, Tourette syndrome, tic disorder, Trichotillomania, a depressive symptom associated with an anxiety disorder, chronic depression, and recurrent depression.