What is the diagnosis for a patient with a history of depression, including postpartum depression, presenting with symptoms of impaired concentration, memory difficulties, anxiety, and social withdrawal, following recent stressors including bereavement?

Major Depressive Disorder (MDD): Venus's history of depression, including postpartum depression, and her current symptoms of low mood, anxiety, sleep disturbances, and difficulty with concentration, suggest that MDD is the most likely diagnosis. The recent stressors, such as the death of her mother and father, may have triggered or worsened her depressive symptoms.

Generalized Anxiety Disorder (GAD): Venus's anxiety in situations where she feels unprepared, avoidance behaviors, and overstimulation suggest that GAD may be a contributing factor to her symptoms.
Attention-Deficit/Hyperactivity Disorder (ADHD): Venus's difficulties with concentration, memory, and maintaining focus, which have been present since high school, may indicate ADHD. However, it is essential to consider that her symptoms may be exacerbated by her depressive and anxiety symptoms.
Post-Traumatic Stress Disorder (PTSD): Although not explicitly stated, Venus's history of substance use and self-medication in her 20s and 30s may suggest that she has experienced traumatic events. Her recent stressors and symptoms of anxiety and avoidance behaviors could be related to PTSD.

Neurocognitive Disorder: Venus's difficulties with concentration, memory, and word recall may indicate a neurocognitive disorder, such as a dementia or a traumatic brain injury. Although less likely, it is crucial to rule out these conditions, as they can have significant implications for her treatment and prognosis.
Sleep Disorder: Venus's sleep disturbances may be a contributing factor to her symptoms. A sleep disorder, such as insomnia or sleep apnea, can have significant consequences if left untreated.
Substance Use Disorder: Although Venus has a history of substance use, it is essential to assess whether she has relapsed or is experiencing symptoms related to substance use.

Frontotemporal Dementia: Although rare, frontotemporal dementia can present with symptoms similar to Venus's, such as difficulties with concentration, memory, and word recall. However, this diagnosis is less likely given her age and the absence of other characteristic symptoms.
Hypothyroidism: Hypothyroidism can cause symptoms such as fatigue, difficulty concentrating, and memory problems. Although less likely, it is essential to rule out this condition, as it can be treated with medication.